Softpanorama

May the source be with you, but remember the KISS principle ;-)
Home Switchboard Unix Administration Red Hat TCP/IP Networks Neoliberalism Toxic Managers
(slightly skeptical) Educational society promoting "Back to basics" movement against IT overcomplexity and  bastardization of classic Unix

Customizing Shell Dot Files: profile, RC-file, and history

News Shell customization Recommended Links Best Shell Books Command history reuse Examples of .bashrc files
Organizing shell aliases into knowledge database Using inputrc for key remapping Shell Prompts Customarization      
Controlling the Prompt in bash BASH Prompt Control Symbols Reference Advanced Unix filesystem navigation   AIX dotfiles .profile
Programmable Keyboards Sysadmin Horror Stories Unix shells history Tips

Humor

 Etc

Introduction

Each user's common home directory contains a set of master dot files for login and run-control support. These files can be modified to customize the user environment. Dot files is probably the most important avenue of such customarization. Usage of programmable keyboard  and macros is another important avenue that is they are complementary in nature to customized dot files.

Why "." files? You probably know that ls does not show these files by default - they are somewhat hidden. Other than this, the "." files have no special significance. It is simply a Unix convention.

Creation of convenient environment for  your work is one of the criteria (and demonstration) of sysadmin abilities. Actually if a Unix sysadmin does not have his own dot files this is a warning sign as for his/her qualification.

customized dot file not only increase productivity and cut the number of keystrokes one uses during typical operations. Good prompt and carefully selected aliases and functions increases situation awareness and prevent some horrible blunders, especially if your under stress and/or in a hurry. For example such horrible mistake as rebooting the wrong server in a hurry can be prevented by redefining shutdown as a function for interactive sessions only and asking the situation "If this is a right server to reboot". Just displaying the name of the server is of great importance. Of course you should never use "now" in shutdown command anyway but mistakes are made.  

Especially acute situation arise when you find yourself working on the server or workstation that has default dot files and do not have access to your "native" dot files. In this case sites like  dotfiles.org community can be of tremendous help. See also examples in News section  below and Examples of .bashrc files

Just a couple of adjustments to .bash_profile (or .profile if ksh is used) and .bashrc (or .rc) do wonders to your mood.

This way you can turn a SNAFU into educational experience.

Key dot files

There are several fundamental files used by Unix shells such as bash or ksh93:

  1. /etc/profile -- system wide shell initialization script. Executed during login only for each user including root. .profile is a user customizable part of the profile.  Bash uses .bash_profile instead of .profile if it exists.

  2.  ~/profile, this file $HOME/.profile, also known as ~/.profile, is run exactly once per session -- when you login. As it runs after system wide /etc/profile script, the typical thing you want to do in this script is set, or modify, environment variables. If you set a shell option or alias in this script, it will not be propagated to a subshell.

  3. $ENV file (name is user selectable but usually .bashrc .kshrc,  .kshenv or .aliases). Executed upon each non-interactive invocation of the shell. If this variable contains a name of a file readable by a particular user it will be executed each time shell is invoked.

    The main difference between your $HOME/.profile and $ENV is that $ENV is run every time a shell starts, whicle $HOME/.profile runs instead when you login into interactive session. For this reason, the typical thing you want to do in this script is set, or modify

    Do not set shell options environment variables (with possible exception of $PATH) in this file.  Please note that all exported environment variables are propagated to the child processes from the login shell.

    The file should be minimal. Really minimal. Such things as aliases which are used only in interactive sessions are probably redundant and inefficient because.

Which file is executed when

Contrary to popular urban myth .logout file is not executed on logoff for ksh users. You can make it execute by defining it as an alias for exit.

See also DotFiles - Greg's Wiki

Other dot files

There are many other dot files. See In Unix, what are some common dot files.  Among them:

 

- Dr. Nikolai Bezroukov

NEWS CONTENTS

Old News ;-)

[Mar 24, 2021] What commands are missing from your bashrc file- - Enable Sysadmin

Mar 24, 2021 | www.redhat.com

The idea was that sharing this would inspire others to improve their bashrc savviness. Take a look at what our Sudoers group shared and, please, borrow anything you like to make your sysadmin life easier.

[ You might also like: Parsing Bash history in Linux ]

Jonathan Roemer 
# Require confirmation before overwriting target files. This setting keeps me from deleting things I didn't expect to, etc
alias cp='cp -i'
alias mv='mv -i'
alias rm='rm -i'

# Add color, formatting, etc to ls without re-typing a bunch of options every time
alias ll='ls -alhF'
alias ls="ls --color"
# So I don't need to remember the options to tar every time
alias untar='tar xzvf'
alias tarup='tar czvf'

# Changing the default editor, I'm sure a bunch of people have this so they don't get dropped into vi instead of vim, etc. A lot of distributions have system default overrides for these, but I don't like relying on that being around
alias vim='nvim'
alias vi='nvim'
Valentin Bajrami

Here are a few functions from my ~/.bashrc file:

# Easy copy the content of a file without using cat / selecting it etc. It requires xclip to be installed
# Example:  _cp /etc/dnsmasq.conf
_cp()
{
  local file="$1"
  local st=1
  if [[ -f $file ]]; then
    cat "$file" | xclip -selection clipboard
    st=$?
  else
    printf '%s\n' "Make sure you are copying the content of a file" >&2
  fi
  return $st    
}

# This is the function to paste the content. The content is now in your buffer.
# Example: _paste   

_paste()
{
  xclip -selection cliboard -o
}

# Generate a random password without installing any external tooling
genpw()
{
  alphanum=( {a..z} {A..Z} {0..9} ); for((i=0;i<=${#alphanum[@]};i++)); do printf '%s' "${alphanum[@]:$((RANDOM%255)):1}"; done; echo
}
# See what command you are using the most (this parses the history command)
cm() {
  history | awk ' { a[$4]++ } END { for ( i in a ) print a[i], i | "sort -rn | head -n10"}' | awk '$1 > max{ max=$1} { bar=""; i=s=10*$1/max;while(i-->0)bar=bar"#"; printf "%25s %15d %s %s", $2, $1,bar, "\n"; }'
}
Peter Gervase

For shutting down at night, I kill all SSH sessions and then kill any VPN connections:

#!/bin/bash
/usr/bin/killall ssh
/usr/bin/nmcli connection down "Raleigh (RDU2)"
/usr/bin/nmcli connection down "Phoenix (PHX2)"
Valentin Rothberg 
alias vim='nvim'
alias l='ls -CF --color=always''
alias cd='cd -P' # follow symlinks
alias gits='git status'
alias gitu='git remote update'
alias gitum='git reset --hard upstream/master'
Steve Ovens 
alias nano='nano -wET 4'
alias ls='ls --color=auto'
PS1="\[\e[01;32m\]\u@\h \[\e[01;34m\]\w  \[\e[01;34m\]$\[\e[00m\] "
export EDITOR=nano
export AURDEST=/var/cache/pacman/pkg
PATH=$PATH:/home/stratus/.gem/ruby/2.7.0/bin
alias mp3youtube='youtube-dl -x --audio-format mp3'
alias grep='grep --color'
alias best-youtube='youtube-dl -r 1M --yes-playlist -f 'bestvideo[ext=mp4]+bestaudio[ext=m4a]''
alias mv='mv -vv'
shopt -s histappend
HISTCONTROL=ignoreboth
Jason Hibbets

While my bashrc aliases aren't as sophisticated as the previous technologists, you can probably tell I really like shortcuts:

# User specific aliases and functions

alias q='exit'
alias h='cd ~/'
alias c='clear'
alias m='man'
alias lsa='ls -al'
alias s='sudo su -'
More Linux resources Bonus: Organizing bashrc files and cleaning up files

We know many sysadmins like to script things to make their work more automated. Here are a few tips from our Sudoers that you might find useful.

Chris Collins

I don't know who I need to thank for this, some awesome woman on Twitter whose name I no longer remember, but it's changed the organization of my bash aliases and commands completely.

I have Ansible drop individual <something>.bashrc files into ~/.bashrc.d/ with any alias or command or shortcut I want, related to any particular technology or Ansible role, and can manage them all separately per host. It's been the best single trick I've learned for .bashrc files ever.

Git stuff gets a ~/.bashrc.d/git.bashrc , Kubernetes goes in ~/.bashrc.d/kube.bashrc .

if [ -d ${HOME}/.bashrc.d ]
then
  for file in ~/.bashrc.d/*.bashrc
  do
    source "${file}"
  done
fi
Peter Gervase

These aren't bashrc aliases, but I use them all the time. I wrote a little script named clean for getting rid of excess lines in files. For example, here's nsswitch.conf with lots of comments and blank lines:

[pgervase@pgervase etc]$ head authselect/nsswitch.conf
# Generated by authselect on Sun Dec  6 22:12:26 2020
# Do not modify this file manually.

# If you want to make changes to nsswitch.conf please modify
# /etc/authselect/user-nsswitch.conf and run 'authselect apply-changes'.
#
# Note that your changes may not be applied as they may be
# overwritten by selected profile. Maps set in the authselect
# profile always take precedence and overwrites the same maps
# set in the user file. Only maps that are not set by the profile

[pgervase@pgervase etc]$ wc -l authselect/nsswitch.conf
80 authselect/nsswitch.conf

[pgervase@pgervase etc]$ clean authselect/nsswitch.conf
passwd:     sss files systemd
group:      sss files systemd
netgroup:   sss files
automount:  sss files
services:   sss files
shadow:     files sss
hosts:      files dns myhostname
bootparams: files
ethers:     files
netmasks:   files
networks:   files
protocols:  files
rpc:        files
publickey:  files
aliases:    files

[pgervase@pgervase etc]$ cat `which clean`
#! /bin/bash
#
/bin/cat $1 | /bin/sed 's/^[ \t]*//' | /bin/grep -v -e "^#" -e "^;" -e "^[[:space:]]*$" -e "^[ \t]+"

[ Free online course: Red Hat Enterprise Linux technical overview . ]

[Jan 26, 2019] Shell startup scripts

flowblok's blog
that diagram shows what happens according to the man page, and not what happens when you actually try it out in real life. This second diagram more accurately captures the insanity of bash:

See how remote interactive login shells read /etc/bash.bashrc, but normal interactive login shells don't? Sigh.

Finally, here's a repository containing my implementation and the graphviz files for the above diagram. If your POSIX-compliant shell isn't listed here, or if I've made a horrible mistake (or just a tiny one), please send me a pull request or make a comment below, and I'll update this post accordingly.

[1]

and since I'm writing this, I can make you say whatever I want for the purposes of narrative.

[Jan 26, 2019] Shell startup script order of execution

Highly recommended!
Jan 26, 2019 | flowblok.id.au

Adrian • a month ago ,

6 years late, but...

In my experience, if your bash sources /etc/bash.bashrc, odds are good it also sources /etc/bash.bash_logout or something similar on logout (after ~/.bash_logout, of course).

From bash-4.4/config-top.h:

/* System-wide .bashrc file for interactive shells. */
/* #define SYS_BASHRC "/etc/bash.bashrc" */

/* System-wide .bash_logout for login shells. */
/* #define SYS_BASH_LOGOUT "/etc/bash.bash_logout" */

(Yes, they're disabled by default.)

Check the FILES section of your system's bash man page for details.

[Dec 20, 2018] Your .bashrc

Notable quotes:
"... Erm, did you know that `tar` autoextracts these days? This will work for pretty much anything: ..."
Dec 20, 2018 | forums.debian.net

pawRoot " 2018-10-15 17:13

Just spent some time editing .bashrc to make my life easier, and wondering if anyone has some cool "tricks" for bash as well.

Here is mine:

Code: Select all
# changing shell appearance
PS1='\[\033[0;32m\]\[\033[0m\033[0;32m\]\u\[\033[0;36m\] @ \[\033[0;36m\]\h \w\[\033[0;32m\]$(__git_ps1)\n\[\033[0;32m\]└─\[\033[0m\033[0;32m\] \$\[\033[0m\033[0;32m\] ▶\[\033[0m\] '

# aliases
alias la="ls -la --group-directories-first --color"

# clear terminal
alias cls="clear"

#
alias sup="sudo apt update && sudo apt upgrade"

# search for package
alias apts='apt-cache search'

# start x session
alias x="startx"

# download mp3 in best quality from YouTube
# usage: ytmp3 https://www.youtube.com/watch?v=LINK

alias ytmp3="youtube-dl -f bestaudio --extract-audio --audio-format mp3 --audio-quality 0"

# perform 'la' after 'cd'

alias cd="listDir"

listDir() {
builtin cd "$*"
RESULT=$?
if [ "$RESULT" -eq 0 ]; then
la
fi
}

# type "extract filename" to extract the file

extract () {
if [ -f $1 ] ; then
case $1 in
*.tar.bz2) tar xvjf $1 ;;
*.tar.gz) tar xvzf $1 ;;
*.bz2) bunzip2 $1 ;;
*.rar) unrar x $1 ;;
*.gz) gunzip $1 ;;
*.tar) tar xvf $1 ;;
*.tbz2) tar xvjf $1 ;;
*.tgz) tar xvzf $1 ;;
*.zip) unzip $1 ;;
*.Z) uncompress $1 ;;
*.7z) 7z x $1 ;;
*) echo "don't know how to extract '$1'..." ;;
esac
else
echo "'$1' is not a valid file!"
fi
}

# obvious one

alias ..="cd .."
alias ...="cd ../.."
alias ....="cd ../../.."
alias .....="cd ../../../.."

# tail all logs in /var/log
alias logs="find /var/log -type f -exec file {} \; | grep 'text' | cut -d' ' -f1 | sed -e's/:$//g' | grep -v '[0-9]$' | xargs tail -f"

Head_on_a_Stick " 2018-10-15 18:11

pawRoot wrote:
Code: Select all
extract () {
if [ -f $1 ] ; then
case $1 in
*.tar.bz2) tar xvjf $1 ;;
*.tar.gz) tar xvzf $1 ;;
*.bz2) bunzip2 $1 ;;
*.rar) unrar x $1 ;;
*.gz) gunzip $1 ;;
*.tar) tar xvf $1 ;;
*.tbz2) tar xvjf $1 ;;
*.tgz) tar xvzf $1 ;;
*.zip) unzip $1 ;;
*.Z) uncompress $1 ;;
*.7z) 7z x $1 ;;
*) echo "don't know how to extract '$1'..." ;;
esac
else
echo "'$1' is not a valid file!"
fi
}
Erm, did you know that `tar` autoextracts these days? This will work for pretty much anything:
Code: Select all
tar xf whatever.tar.whatever
I have these functions in my .mkshrc (bash is bloat!):
Code: Select all
function mnt {
for i in proc sys dev dev/pts; do sudo mount --bind /$i "$1"$i; done &
sudo chroot "$1" /bin/bash
sudo umount -R "$1"{proc,sys,dev}
}

function mkiso {
xorriso -as mkisofs \
-iso-level 3 \
-full-iso9660-filenames \
-volid SharpBang-stretch \
-eltorito-boot isolinux/isolinux.bin \
-eltorito-catalog isolinux/boot.cat \
-no-emul-boot -boot-load-size 4 -boot-info-table \
-isohybrid-mbr isolinux/isohdpfx.bin \
-eltorito-alt-boot \
-e boot/grub/efi.img \
-no-emul-boot -isohybrid-gpt-basdat \
-output ../"$1" ./
}

The mnt function acts like a poor person's arch-chroot and will bind mount /proc /sys & /dev before chrooting then tear it down afterwards.

The mkiso function builds a UEFI-capable Debian live system (with the name of the image given as the first argument).

The only other stuff I have are aliases, not really worth posting.

dbruce wrote: Ubuntu forums try to be like a coffee shop in Seattle. Debian forums strive for the charm and ambience of a skinhead bar in Bacau. We intend to keep it that way.

pawRoot " 2018-10-15 18:23

Head_on_a_Stick wrote: Erm, did you know that `tar` autoextracts these days? This will work for pretty much anything:

But it won't work for zip or rar right ?

None1975 " 2018-10-16 13:02

Here is compilation of cool "tricks" for bash. This is similar to oh-my-zsh. OS: Debian Stretch / WM : Fluxbox
Debian Wiki | DontBreakDebian , My config files in github

debiman " 2018-10-21 14:38

i have a LOT of stuff in my /etc/bash.bashrc, because i want it to be available for the root user too.
i won't post everything, but here's a "best of" from both /etc/bash.bashrc and ~/.bashrc:
Code: Select all
case ${TERM} in
xterm*|rxvt*|Eterm|aterm|kterm|gnome*)
PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND; }'printf "\033]0;%s: %s\007" "${SHELL##*/}" "${PWD/#$HOME/\~}"'
;;
screen)
PROMPT_COMMAND=${PROMPT_COMMAND:+$PROMPT_COMMAND; }'printf "\033_%s@%s:%s\033\\" "${USER}" "${HOSTNAME%%.*}" "${PWD/#$HOME/\~}"'
;;
linux)
setterm --blength 0
setterm --blank 4
setterm --powerdown 8
;;
esac

PS2='cont> '
PS3='Choice: '
PS4='DEBUG: '

# Bash won't get SIGWINCH if another process is in the foreground.
# Enable checkwinsize so that bash will check the terminal size when
# it regains control.
# http://cnswww.cns.cwru.edu/~chet/bash/FAQ (E11)
shopt -s checkwinsize

# forums.bunsenlabs.org/viewtopic.php?pid=27494#p27494
# also see aliases '...' and '....'
shopt -s autocd
# opensource.com/article/18/5/bash-tricks
shopt -s cdspell

# as big as possible!!!
HISTSIZE=500000
HISTFILESIZE=2000000

# unix.stackexchange.com/a/18443
# history: erase duplicates...
HISTCONTROL=ignoredups:erasedups
shopt -s histappend

# next: enables usage of CTRL-S (backward search) with CTRL-R (forward search)
# digitalocean.com/community/tutorials/how-to-use-bash-history-commands-and-expansions-on-a-linux-vps#searching-through-bash-history
stty -ixon

if [[ ${EUID} == 0 ]] ; then
# root = color=1 # red
if [ "$TERM" != "linux" ]; then
PS1="\[$(tput setaf 1)\]\[$(tput rev)\] \[$(tput sgr0)\]\[$(tput setaf 5)\]\${?#0}\[$(tput setaf 1)\] \u@\h \w\[$(tput sgr0)\]\n\[$(tput rev)\] \[$(tput sgr0)\] "
else
# adding \t = time to tty prompt
PS1="\[$(tput setaf 1)\]\[$(tput rev)\] \[$(tput sgr0)\]\[$(tput setaf 5)\]\${?#0}\[$(tput setaf 1)\] \t \u@\h \w\[$(tput sgr0)\]\n\[$(tput rev)\] \[$(tput sgr0)\] "
fi
else
if [ "$TERM" != "linux" ]; then
PS1="\[$(tput setaf 2)\]\[$(tput rev)\] \[$(tput sgr0)\]\[$(tput setaf 5)\]\${?#0}\[$(tput setaf 2)\] \u@\h \w\[$(tput sgr0)\]\n\[$(tput rev)\] \[$(tput sgr0)\] "
else
# adding \t = time to tty prompt
PS1="\[$(tput setaf 2)\]\[$(tput rev)\] \[$(tput sgr0)\]\[$(tput setaf 5)\]\${?#0}\[$(tput setaf 2)\] \t \u@\h \w\[$(tput sgr0)\]\n\[$(tput rev)\] \[$(tput sgr0)\] "
fi
fi

[ -r /usr/share/bash-completion/bash_completion ] && . /usr/share/bash-completion/bash_completion || true

export EDITOR="nano"

man() {
env LESS_TERMCAP_mb=$(printf "\e[1;31m") \
LESS_TERMCAP_md=$(printf "\e[1;31m") \
LESS_TERMCAP_me=$(printf "\e[0m") \
LESS_TERMCAP_se=$(printf "\e[0m") \
LESS_TERMCAP_so=$(printf "\e[7m") \
LESS_TERMCAP_ue=$(printf "\e[0m") \
LESS_TERMCAP_us=$(printf "\e[1;32m") \
man "$@"
}
#LESS_TERMCAP_so=$(printf "\e[1;44;33m")
# that used to be in the man function for less's annoyingly over-colorful status line.
# changed it to simple reverse video (tput rev)

alias ls='ls --group-directories-first -hF --color=auto'
alias ll='ls --group-directories-first -hF --color=auto -la'
alias mpf='/usr/bin/ls -1 | mpv --playlist=-'
alias ruler='slop -o -c 1,0.3,0'
alias xmeasure='slop -o -c 1,0.3,0'
alias obxprop='obxprop | grep -v _NET_WM_ICON'
alias sx='exec startx > ~/.local/share/xorg/xlog 2>&1'
alias pngq='pngquant --nofs --speed 1 --skip-if-larger --strip '
alias screencap='ffmpeg -r 15 -s 1680x1050 -f x11grab -i :0.0 -vcodec msmpeg4v2 -qscale 2'
alias su='su -'
alias fblc='fluxbox -list-commands | column'
alias torrench='torrench -t -k -s -x -r -l -i -b --sorted'
alias F5='while sleep 60; do notify-send -u low "Pressed F5 on:" "$(xdotool getwindowname $(xdotool getwindowfocus))"; xdotool key F5; done'
alias aurs='aurman --sort_by_name -Ss'
alias cal3='cal -3 -m -w --color'
alias mkdir='mkdir -p -v'
alias ping='ping -c 5'
alias cd..='cd ..'
alias off='systemctl poweroff'
alias xg='xgamma -gamma'
alias find='find 2>/dev/null'
alias stressme='stress --cpu 8 --io 4 --vm 2 --vm-bytes 128M --timeout'
alias hf='history|grep'
alias du1='du -m --max-depth=1|sort -g|sed "s/\t./M\t/g ; s/\///g"'
alias zipcat='gunzip -c'

mkcd() {
mkdir -p "$1"
echo cd "$1"
cd "$1"
}

[Jul 29, 2017] If processes inherit the parents environment, why do we need export?

Notable quotes:
"... "Processes inherit their environment from their parent (the process which started them)." ..."
"... in the environment ..."
Jul 29, 2017 | unix.stackexchange.com
Amelio Vazquez-Reina asked May 19 '14

I read here that the purpose of export in a shell is to make the variable available to sub-processes started from the shell.

However, I have also read here and here that "Processes inherit their environment from their parent (the process which started them)."

If this is the case, why do we need export ? What am I missing?

Are shell variables not part of the environment by default? What is the difference?

Your assumption is that all shell variables are in the environment . This is incorrect. The export command is what defines a name to be in the environment at all. Thus: 

a=1
b=2
export b

results in the current shell knowing that $a expands to 1 and $b to 2, but subprocesses will not know anything about a because it is not part of the environment (even in the current shell).

Some useful tools:

Alternatives to export :

  1. name=val command # Assignment before command exports that name to the command.
  2. declare/local -x name # Exports name, particularly useful in shell functions when you want to avoid exposing the name to outside scope.
====

There's a difference between shell variables and environment variables. If you define a shell variable without export ing it, it is not added to the processes environment and thus not inherited to its children.

Using export you tell the shell to add the shell variable to the environment. You can test this using printenv (which just prints its environment to stdout, since it's a child-process you see the effect of export ing variables):

#!/bin/sh
MYVAR="my cool variable"
echo "Without export:"
printenv | grep MYVAR
echo "With export:"
export MYVAR 
printenv | grep MYVAR
A variable, once exported, is part of the environment. PATH is exported in the shell itself, while custom variables can be exported as needed.

... ... ..

[Jul 29, 2017] Why does subshell not inherit exported variable (PS1)?

Jul 29, 2017 | superuser.com
up vote down vote favorite 1 I am using startx to start the graphical environment. I have a very simple .xinitrc which I will add things to as I set up the environment, but for now it is as follows: 

catwm
&
# Just a basic window manager, for testing.


xterm

The reason I background the WM and foreground terminal and not the other way around as often is done, is because I would like to be able to come back to the virtual text console after typing exit in xterm . This appears to work as described.

The problem is that the PS1 variable that currently is set to my preference in /etc/profile.d/user.sh (which is sourced from /etc/profile supplied by distro), does not appear to propagate to the environment of the xterm mentioned above. The relevant process tree is as follows:


\_
bash
    \_ xinit
home
user
/.
xinitrc
--
etc
X11
xinit
xserverrc
auth
tmp
serverauth
ggJna3I0vx
        \_
usr
bin
nolisten tcp
auth
tmp
serverauth
ggJna3I0vx vt1
        \_ sh
home
user
/.
xinitrc
            \_
home
user
catwm
            \_ xterm
                \_ bash

The shell started by xterm appears to be interactive, the shell executing .xinitrc however is not. I am ok with both, the assumptions about interactivity seem to be perfectly valid, but now I have a non-interactive shell that spawns an interactive shell indirectly, and the interactive shell has no chance to automatically inherit the prompt, because the prompt was unset or otherwise made unavailable higher up the process tree.

How do I go about getting my prompt back? bash environment-variables sh

share improve this question edited Oct 21 '13 at 11:39 asked Oct 21 '13 at 9:51 amn 453 12 29
down vote accepted

Commands env and export list only variables which are exported. $PS1 is usually not exported. Try echo $PS1 in your shell to see actual value of $PS1 .

Non-interactive shells usually do not have $PS1 . Non-interactive bash explicitly unsets $PS1 . 1 You can check if bash is interactive by echo $- . If the output contains i then it is interactive. You can explicitly start interactive shell by using the option on the command line: bash -i . Shell started with -c is not interactive.

The /etc/profile script is read for a login shell. You can start the shell as a login shell by: bash -l .

With bash shell the scripts /etc/bash.bashrc and ~/.bashrc are usually used to set $PS1 . Those scripts are sourced when interactive non-login shell is started. It is your case in the xterm .

See Setting the PS? Strings Permanently

Possible solutions
share improve this answer edited Oct 22 '13 at 16:45 answered Oct 21 '13 at 11:19 pabouk 4,250 25 40
I am specifically avoiding to set PS1 in .bashrc or /etc/bash.bashrc (which is executed as well), to retain POSIX shell compatibility. These do not set or unset PS1 . PS1 is set in /etc/profile.d/user.sh , which is sourced by /etc/profile . Indeed, this file is only executed for login shells, however I do export PS1 from /etc/profile.d/user.sh exactly because I want propagation of my preferred value down the process tree. So it shouldn't matter which subshells are login and/or interactive ones then, should it? – amn Oct 21 '13 at 11:32
It seems that bash removes the PS1 variable. What exactly do you want to achieve by "POSIX shell compatibility"? Do you want to be able to replace bash by a different POSIX-compliant shell and retain the same functionality? Based on my tests bash removes PS1 when it is started as non-interactive. I think of two simple solutions: 1. start the shell as a login shell with the -l option (attention for actions in the startup scripts which should be started only at login) 2. start the intermediate shells as interactive with the -i option. – pabouk Oct 21 '13 at 12:00
I try to follow interfaces and specifications, not implementations - hence POSIX compatibility. That's important (to me). I already have one login shell - the one started by /usr/bin/login . I understand that a non-interactive shell doesn't need prompt, but unsetting a variable is too much - I need the prompt in an interactive shell (spawned and used by xterm ) later on. What am I doing wrong? I guess most people set their prompt in .bashrc which is sourced by bash anyway, and so the prompt survives. I try to avoid .bashrc however. – amn Oct 22 '13 at 12:12
@amn: I have added various possible solutions to the reply. – pabouk Oct 22 '13 at 16:46

[Jul 29, 2017] Bash subshell mystery

Notable quotes:
"... The subshell created using parentheses does not ..."
Jul 29, 2017 | stackoverflow.com

user3718463 , asked Sep 27 '14 at 21:41

The Learning Bash Book mention that a subshell will inherit only environment variabels and file descriptors , ...etc and that it will not inherit variables that are not exported of 
$ var=15
$ (echo $var)
15
$ ./file # this file include the same command echo $var

$

As i know the shell will create two subshells for () case and for ./file, but why in () case the subshell identified the var variable although it is not exported and in the ./file case it did not identify it ?

...

I tried to use strace to figure out how this happens and surprisingly i found that bash will use the same arguments for the clone system call so this means that the both forked process in () and ./file should have the same process address space of the parent, so why in () case the variable is visible to the subshell and the same does not happen for ./file case although the same arguments is based with clone system call ?

Alfe , answered Sep 27 '14 at 23:16

The subshell created using parentheses does not use an execve() call for the new process, the calling of the script does. At this point the variables from the parent shell are handled differently: The execve() passes a deliberate set of variables (the script-calling case) while not calling execve() (the parentheses case) leaves the complete set of variables intact.

Your probing using strace should have shown exactly that difference; if you did not see it, I can only assume that you made one of several possible mistakes. I will just strip down what I did to show the difference, then you can decide for yourself where your error was.

... ... ...

Nicolas Albert , answered Sep 27 '14 at 21:43

You have to export your var for child process: 


export var
15

Once exported, the variable is used for all children process at the launch time (not export time).



var
15



export var

is same as



export var
var
15

is same as



export var
15

Export can be cancelled using unset . Sample: unset var .

user3718463 , answered Sep 27 '14 at 23:11

The solution for this mystery is that subshells inherit everything from the parent shell including all shell variables because they are simply called with fork or clone so they share the same memory space with the parent shell , that's why this will work 
$ var=15
$ (echo $var)
15

But in the ./file , the subshell will be later followed by exec or execv system call which will clear all the previous parent variables but we still have the environment variables you can check this out using strace using -f to monitor the child subshell and you will find that there is a call to execv

[Jul 29, 2017] How To Read and Set Environmental and Shell Variables on a Linux VPS

Mar 03, 2014 | www.digitalocean.com
Introduction

When interacting with your server through a shell session, there are many pieces of information that your shell compiles to determine its behavior and access to resources. Some of these settings are contained within configuration settings and others are determined by user input.

One way that the shell keeps track of all of these settings and details is through an area it maintains called the environment . The environment is an area that the shell builds every time that it starts a session that contains variables that define system properties.

In this guide, we will discuss how to interact with the environment and read or set environmental and shell variables interactively and through configuration files. We will be using an Ubuntu 12.04 VPS as an example, but these details should be relevant on any Linux system.

How the Environment and Environmental Variables Work

Every time a shell session spawns, a process takes place to gather and compile information that should be available to the shell process and its child processes. It obtains the data for these settings from a variety of different files and settings on the system.

Basically the environment provides a medium through which the shell process can get or set settings and, in turn, pass these on to its child processes.

The environment is implemented as strings that represent key-value pairs. If multiple values are passed, they are typically separated by colon (:) characters. Each pair will generally will look something like this:

KEY
value1
value2:...

If the value contains significant white-space, quotations are used:

KEY
="
value with spaces
"

The keys in these scenarios are variables. They can be one of two types, environmental variables or shell variables.

Environmental variables are variables that are defined for the current shell and are inherited by any child shells or processes. Environmental variables are used to pass information into processes that are spawned from the shell.

Shell variables are variables that are contained exclusively within the shell in which they were set or defined. They are often used to keep track of ephemeral data, like the current working directory.

By convention, these types of variables are usually defined using all capital letters. This helps users distinguish environmental variables within other contexts.

Printing Shell and Environmental Variables

Each shell session keeps track of its own shell and environmental variables. We can access these in a few different ways.

We can see a list of all of our environmental variables by using the env or printenv commands. In their default state, they should function exactly the same:

printenv


SHELL=/bin/bash
TERM=xterm
USER=demouser
LS_COLORS=rs=0:di=01;34:ln=01;36:mh=00:pi=40;33:so=01;35:do=01;35:bd=40;33;01:cd=40;33;01:or=40;31;01:su=37;41:sg=30;43:ca:...
MAIL=/var/mail/demouser
PATH=/usr/local/bin:/usr/bin:/bin:/usr/local/games:/usr/games
PWD=/home/demouser
LANG=en_US.UTF-8
SHLVL=1
HOME=/home/demouser
LOGNAME=demouser
LESSOPEN=| /usr/bin/lesspipe %s
LESSCLOSE=/usr/bin/lesspipe %s %s
_=/usr/bin/printenv

This is fairly typical of the output of both printenv and env . The difference between the two commands is only apparent in their more specific functionality. For instance, with printenv , you can requests the values of individual variables:

printenv SHELL


/bin/bash

On the other hand, env let's you modify the environment that programs run in by passing a set of variable definitions into a command like this:

env VAR1="blahblah" command_to_run command_options

Since, as we learned above, child processes typically inherit the environmental variables of the parent process, this gives you the opportunity to override values or add additional variables for the child.

As you can see from the output of our printenv command, there are quite a few environmental variables set up through our system files and processes without our input.

These show the environmental variables, but how do we see shell variables?

The set command can be used for this. If we type set without any additional parameters, we will get a list of all shell variables, environmental variables, local variables, and shell functions:

set


BASH=/bin/bash
BASHOPTS=checkwinsize:cmdhist:expand_aliases:extglob:extquote:force_fignore:histappend:interactive_comments:login_shell:progcomp:promptvars:sourcepath
BASH_ALIASES=()
BASH_ARGC=()
BASH_ARGV=()
BASH_CMDS=()
. . .

This is usually a huge list. You probably want to pipe it into a pager program to deal with the amount of output easily:

set | less

The amount of additional information that we receive back is a bit overwhelming. We probably do not need to know all of the bash functions that are defined, for instance.

We can clean up the output by specifying that set should operate in POSIX mode, which won't print the shell functions. We can execute this in a sub-shell so that it does not change our current environment:

(set -o posix; set)

This will list all of the environmental and shell variables that are defined.

We can attempt to compare this output with the output of the env or printenv commands to try to get a list of only shell variables, but this will be imperfect due to the different ways that these commands output information:

comm -23 <(set -o posix; set | sort) <(env | sort)

This will likely still include a few environmental variables, due to the fact that the set command outputs quoted values, while the printenv and env commands do not quote the values of strings.

This should still give you a good idea of the environmental and shell variables that are set in your session.

These variables are used for all sorts of things. They provide an alternative way of setting persistent values for the session between processes, without writing changes to a file.

Common Environmental and Shell Variables

Some environmental and shell variables are very useful and are referenced fairly often.

Here are some common environmental variables that you will come across:

In addition to these environmental variables, some shell variables that you'll often see are:

Setting Shell and Environmental Variables

To better understand the difference between shell and environmental variables, and to introduce the syntax for setting these variables, we will do a small demonstration.

Creating Shell Variables

We will begin by defining a shell variable within our current session. This is easy to accomplish; we only need to specify a name and a value. We'll adhere to the convention of keeping all caps for the variable name, and set it to a simple string.

TEST_VAR='Hello World!'

Here, we've used quotations since the value of our variable contains a space. Furthermore, we've used single quotes because the exclamation point is a special character in the bash shell that normally expands to the bash history if it is not escaped or put into single quotes.

We now have a shell variable. This variable is available in our current session, but will not be passed down to child processes.

We can see this by grepping for our new variable within the set output:

set | grep TEST_VAR


TEST_VAR='Hello World!'

We can verify that this is not an environmental variable by trying the same thing with printenv :

printenv | grep TEST_VAR

No out should be returned.

Let's take this as an opportunity to demonstrate a way of accessing the value of any shell or environmental variable.

echo $TEST_VAR


Hello World!

As you can see, reference the value of a variable by preceding it with a $ sign. The shell takes this to mean that it should substitute the value of the variable when it comes across this.

So now we have a shell variable. It shouldn't be passed on to any child processes. We can spawn a new bash shell from within our current one to demonstrate:

bash
echo $TEST_VAR

If we type bash to spawn a child shell, and then try to access the contents of the variable, nothing will be returned. This is what we expected.

Get back to our original shell by typing exit :

exit
Creating Environmental Variables

Now, let's turn our shell variable into an environmental variable. We can do this by exporting the variable. The command to do so is appropriately named:

export TEST_VAR

This will change our variable into an environmental variable. We can check this by checking our environmental listing again:

printenv | grep TEST_VAR


TEST_VAR=Hello World!

This time, our variable shows up. Let's try our experiment with our child shell again:

bash
echo $TEST_VAR


Hello World!

Great! Our child shell has received the variable set by its parent. Before we exit this child shell, let's try to export another variable. We can set environmental variables in a single step like this:

export NEW_VAR="Testing export"

Test that it's exported as an environmental variable:

printenv | grep NEW_VAR


NEW_VAR=Testing export

Now, let's exit back into our original shell:

exit

Let's see if our new variable is available:

echo $NEW_VAR

Nothing is returned.

This is because environmental variables are only passed to child processes. There isn't a built-in way of setting environmental variables of the parent shell. This is good in most cases and prevents programs from affecting the operating environment from which they were called.

The NEW_VAR variable was set as an environmental variable in our child shell. This variable would be available to itself and any of its child shells and processes. When we exited back into our main shell, that environment was destroyed.

Demoting and Unsetting Variables

We still have our TEST_VAR variable defined as an environmental variable. We can change it back into a shell variable by typing:

export -n TEST_VAR

It is no longer an environmental variable:

printenv | grep TEST_VAR

However, it is still a shell variable:

set | grep TEST_VAR


TEST_VAR='Hello World!'

If we want to completely unset a variable, either shell or environmental, we can do so with the unset command:

unset TEST_VAR

We can verify that it is no longer set:

echo $TEST_VAR

Nothing is returned because the variable has been unset.

Setting Environmental Variables at Login

We've already mentioned that many programs use environmental variables to decide the specifics of how to operate. We do not want to have to set important variables up every time we start a new shell session, and we have already seen how many variables are already set upon login, so how do we make and define variables automatically?

This is actually a more complex problem than it initially seems, due to the numerous configuration files that the bash shell reads depending on how it is started.

The Difference between Login, Non-Login, Interactive, and Non-Interactive Shell Sessions

The bash shell reads different configuration files depending on how the session is started.

One distinction between different sessions is whether the shell is being spawned as a "login" or "non-login" session.

A login shell is a shell session that begins by authenticating the user. If you are signing into a terminal session or through SSH and authenticate, your shell session will be set as a "login" shell.

If you start a new shell session from within your authenticated session, like we did by calling the bash command from the terminal, a non-login shell session is started. You were were not asked for your authentication details when you started your child shell.

Another distinction that can be made is whether a shell session is interactive, or non-interactive.

An interactive shell session is a shell session that is attached to a terminal. A non-interactive shell session is one is not attached to a terminal session.

So each shell session is classified as either login or non-login and interactive or non-interactive.

A normal session that begins with SSH is usually an interactive login shell. A script run from the command line is usually run in a non-interactive, non-login shell. A terminal session can be any combination of these two properties.

Whether a shell session is classified as a login or non-login shell has implications on which files are read to initialize the shell session.

A session started as a login session will read configuration details from the /etc/profile file first. It will then look for the first login shell configuration file in the user's home directory to get user-specific configuration details.

It reads the first file that it can find out of ~/.bash_profile , ~/.bash_login , and ~/.profile and does not read any further files.

In contrast, a session defined as a non-login shell will read /etc/bash.bashrc and then the user-specific ~/.bashrc file to build its environment.

Non-interactive shells read the environmental variable called BASH_ENV and read the file specified to define the new environment.

Implementing Environmental Variables

As you can see, there are a variety of different files that we would usually need to look at for placing our settings.

This provides a lot of flexibility that can help in specific situations where we want certain settings in a login shell, and other settings in a non-login shell. However, most of the time we will want the same settings in both situations.

Fortunately, most Linux distributions configure the login configuration files to source the non-login configuration files. This means that you can define environmental variables that you want in both inside the non-login configuration files. They will then be read in both scenarios.

We will usually be setting user-specific environmental variables, and we usually will want our settings to be available in both login and non-login shells. This means that the place to define these variables is in the ~/.bashrc file.

Open this file now:

nano ~/.bashrc

This will most likely contain quite a bit of data already. Most of the definitions here are for setting bash options, which are unrelated to environmental variables. You can set environmental variables just like you would from the command line:

export VARNAME=value

We can then save and close the file. The next time you start a shell session, your environmental variable declaration will be read and passed on to the shell environment. You can force your current session to read the file now by typing:

source ~/.bashrc

If you need to set system-wide variables, you may want to think about adding them to /etc/profile , /etc/bash.bashrc , or /etc/environment .

Conclusion

Environmental and shell variables are always present in your shell sessions and can be very useful. They are an interesting way for a parent process to set configuration details for its children, and are a way of setting options outside of files.

This has many advantages in specific situations. For instance, some deployment mechanisms rely on environmental variables to configure authentication information. This is useful because it does not require keeping these in files that may be seen by outside parties.

There are plenty of other, more mundane, but more common scenarios where you will need to read or alter the environment of your system. These tools and techniques should give you a good foundation for making these changes and using them correctly.

By Justin Ellingwood

[Jul 29, 2017] shell - Whats the difference between .bashrc, .bash_profile, and .environment - Stack Overflow

Notable quotes:
"... "The following paragraphs describe how bash executes its startup files." ..."
Jul 29, 2017 | stackoverflow.com

up vote 130 down vote favorite 717

Adam Rosenfield , asked Jan 6 '09 at 3:58

I've used a number of different *nix-based systems of the years, and it seems like every flavor of Bash I use has a different algorithm for deciding which startup scripts to run. For the purposes of tasks like setting up environment variables and aliases and printing startup messages (e.g. MOTDs), which startup script is the appropriate place to do these?

What's the difference between putting things in .bashrc , .bash_profile , and .environment ? I've also seen other files such as .login , .bash_login , and .profile ; are these ever relevant? What are the differences in which ones get run when logging in physically, logging in remotely via ssh, and opening a new terminal window? Are there any significant differences across platforms (including Mac OS X (and its Terminal.app) and Cygwin Bash)?

Cos , answered Jan 6 '09 at 4:18

The main difference with shell config files is that some are only read by "login" shells (eg. when you login from another host, or login at the text console of a local unix machine). these are the ones called, say, .login or .profile or .zlogin (depending on which shell you're using).

Then you have config files that are read by "interactive" shells (as in, ones connected to a terminal (or pseudo-terminal in the case of, say, a terminal emulator running under a windowing system). these are the ones with names like .bashrc , .tcshrc , .zshrc , etc.

bash complicates this in that .bashrc is only read by a shell that's both interactive and non-login , so you'll find most people end up telling their .bash_profile to also read .bashrc with something like

[[ -r ~/.bashrc ]] && . ~/.bashrc

Other shells behave differently - eg with zsh , .zshrc is always read for an interactive shell, whether it's a login one or not.

The manual page for bash explains the circumstances under which each file is read. Yes, behaviour is generally consistent between machines.

.profile is simply the login script filename originally used by /bin/sh . bash , being generally backwards-compatible with /bin/sh , will read .profile if one exists.

Johannes Schaub - litb , answered Jan 6 '09 at 15:21

That's simple. It's explained in man bash : 
... ... ...

Login shells are the ones that are the one you login (so, they are not executed when merely starting up xterm, for example). There are other ways to login. For example using an X display manager. Those have other ways to read and export environment variables at login time.

Also read the INVOCATION chapter in the manual. It says "The following paragraphs describe how bash executes its startup files." , i think that's a spot-on :) It explains what an "interactive" shell is too.

Bash does not know about .environment . I suspect that's a file of your distribution, to set environment variables independent of the shell that you drive.

Jonathan Leffler , answered Jan 6 '09 at 4:13

Classically, ~/.profile is used by Bourne Shell, and is probably supported by Bash as a legacy measure. Again, ~/.login and ~/.cshrc were used by C Shell - I'm not sure that Bash uses them at all.

The ~/.bash_profile would be used once, at login. The ~/.bashrc script is read every time a shell is started. This is analogous to /.cshrc for C Shell.

One consequence is that stuff in ~/.bashrc should be as lightweight (minimal) as possible to reduce the overhead when starting a non-login shell.

I believe the ~/.environment file is a compatibility file for Korn Shell.

Filip Ekberg , answered Jan 6 '09 at 4:03

I found information about .bashrc and .bash_profile here to sum it up:

.bash_profile is executed when you login. Stuff you put in there might be your PATH and other important environment variables.

.bashrc is used for non login shells. I'm not sure what that means. I know that RedHat executes it everytime you start another shell (su to this user or simply calling bash again) You might want to put aliases in there but again I am not sure what that means. I simply ignore it myself.

.profile is the equivalent of .bash_profile for the root. I think the name is changed to let other shells (csh, sh, tcsh) use it as well. (you don't need one as a user)

There is also .bash_logout wich executes at, yeah good guess...logout. You might want to stop deamons or even make a little housekeeping . You can also add "clear" there if you want to clear the screen when you log out.

Also there is a complete follow up on each of the configurations files here

These are probably even distro.-dependant, not all distros choose to have each configuraton with them and some have even more. But when they have the same name, they usualy include the same content.

Rose Perrone , answered Feb 27 '12 at 0:22

According to Josh Staiger , Mac OS X's Terminal.app actually runs a login shell rather than a non-login shell by default for each new terminal window, calling .bash_profile instead of .bashrc.

He recommends:

Most of the time you don't want to maintain two separate config files for login and non-login shells ! when you set a PATH, you want it to apply to both. You can fix this by sourcing .bashrc from your .bash_profile file, then putting PATH and common settings in .bashrc.

To do this, add the following lines to .bash_profile:


if ~/.bashrc ]; then 
    source ~/.bashrc
fi

Now when you login to your machine from a console .bashrc will be called.

PolyThinker , answered Jan 6 '09 at 4:06

A good place to look at is the man page of bash. Here 's an online version. Look for "INVOCATION" section.

seismick , answered May 21 '12 at 10:42

I have used Debian-family distros which appear to execute .profile , but not .bash_profile , whereas RHEL derivatives execute .bash_profile before .profile .

It seems to be a mess when you have to set up environment variables to work in any Linux OS.

[Jul 28, 2017] bash - About .bash_profile, .bashrc, and where should alias be written in - Stack Overflow

Jul 28, 2017 | stackoverflow.com

Community May 23 at 12:17 ♦

Possible Duplicate: What's the difference between .bashrc, .bash_profile, and .environment?

It seems that if I use

alias ls
'ls -F'

inside of .bashrc on Mac OS X, then the newly created shell will not have that alias. I need to type bash again and that alias will be in effect.

And if I log into Linux on the hosting company, the .bashrc file has a comment line that says:

For non-login shell

and the .bash_profile file has a comment that says

for login shell

So where should aliases be written in? How come we separate the login shell and non-login shell?

Some webpage say use .bash_aliases , but it doesn't work on Mac OS X, it seems.

Maggyero edited Apr 25 '16 at 16:24

The reason you separate the login and non-login shell is because the .bashrc file is reloaded every time you start a new copy of Bash.

The .profile file is loaded only when you either log in or use the appropriate flag to tell Bash to act as a login shell.

Personally,

Oh, and the reason you need to type bash again to get the new alias is that Bash loads your .bashrc file when it starts but it doesn't reload it unless you tell it to. You can reload the .bashrc file (and not need a second shell) by typing


source
~/.
bashrc

which loads the .bashrc file as if you had typed the commands directly to Bash.

lhunath answered May 24 '09 at 6:22

Check out http://mywiki.wooledge.org/DotFiles for an excellent resource on the topic aside from man bash .

Summary:

Adam Rosenfield May 24 '09 at 2:46
From the bash manpage:

When bash is invoked as an interactive login shell, or as a non-interactive shell with the --login option, it first reads and executes commands from the file /etc/profile , if that file exists. After reading that file, it looks for ~/.bash_profile , ~/.bash_login , and ~/.profile , in that order, and reads and executes commands from the first one that exists and is readable. The --noprofile option may be used when the shell is started to inhibit this behavior.

When a login shell exits, bash reads and executes commands from the file ~/.bash_logout , if it exists.

When an interactive shell that is not a login shell is started, bash reads and executes commands from ~/.bashrc , if that file exists. This may be inhibited by using the --norc option. The --rcfile file option will force bash to read and execute commands from file instead of ~/.bashrc .

Thus, if you want to get the same behavior for both login shells and interactive non-login shells, you should put all of your commands in either .bashrc or .bash_profile , and then have the other file source the first one.

Adam Rosenfield May 24 '09 at 2:46

.bash_profile is loaded for a "login shell". I am not sure what that would be on OS X, but on Linux that is either X11 or a virtual terminal.

.bashrc is loaded every time you run Bash. That is where you should put stuff you want loaded whenever you open a new Terminal.app window.

I personally put everything in .bashrc so that I don't have to restart the application for changes to take effect.

jonty /.bashrc

Commands vi and man will launch in separate screens when called inside GNU screen. You need my scr file as well.
# $HOME/.bashrc - Jonty's own settings for all shells, not just login
# Jonty 28-Aug-2005

# Shorthands to launch 'vi' or 'man' in separate screens
# when we are running in 'screen'.

function vi() { scr vi $* ; }

function man() { scr man $* ; }

cron0 /.bashrc

This one should probably be .bash_profile.
cron0 /.bashrc 

#.bashrc
export PAGER=less
export EDITOR=vim
export PATH=$HOME/bin:/usr/local/bin:/usr/local/mysql/bin:/opt/local/bin:$PATH
export LESS='-R'

if [[ $- != *i* ]] ; then
         # Shell is non-interactive.  Be done now!
         return
fi


# Fancy PWD display function
# The home directory (HOME) is replaced with a ~
# /home/me/stuff          -> ~/stuff               if USER=me
# /usr/share/big_dir_name -> ../share/big_dir_name if pwdmaxlen=20
bash_prompt_command() {
    # How many characters of the $PWD should be kept
    local pwdmaxlen=15
    # Indicate that there has been dir truncation
    local trunc_symbol=".."
    local dir=${PWD##*/}
    pwdmaxlen=$(( ( pwdmaxlen < ${#dir} ) ? ${#dir} : pwdmaxlen ))
    NEW_PWD=${PWD/#$HOME/\~}
    local pwdoffset=$(( ${#NEW_PWD} - pwdmaxlen ))
    if [ ${pwdoffset} -gt "0" ]
    then
        NEW_PWD=${NEW_PWD:$pwdoffset:$pwdmaxlen}
        NEW_PWD=${trunc_symbol}/${NEW_PWD#*/}
    fi
}

bash_prompt() {
        case $TERM in
    xterm*|rxvt*)
        local TITLEBAR='\[\033]0;\u:${NEW_PWD}\007\]'
        ;;
    *)
        local TITLEBAR=""
        ;;
        esac
        
    local NONE="\[\033[0m\]"    # unsets color to term's fg color
    
    # regular colors
    local K="\[\033[0;30m\]"    # black
    local R="\[\033[0;31m\]"    # red
    local G="\[\033[0;32m\]"    # green
    local Y="\[\033[0;33m\]"    # yellow
    local B="\[\033[0;34m\]"    # blue
    local M="\[\033[0;35m\]"    # magenta
    local C="\[\033[0;36m\]"    # cyan
    local W="\[\033[0;37m\]"    # white
    
    # empahsized (bolded) colors
    local EMK="\[\033[1;30m\]"
    local EMR="\[\033[1;31m\]"
    local EMG="\[\033[1;32m\]"
    local EMY="\[\033[1;33m\]"
    local EMB="\[\033[1;34m\]"
    local EMM="\[\033[1;35m\]"
    local EMC="\[\033[1;36m\]"
    local EMW="\[\033[1;37m\]"
    
    # background colors
    local BGK="\[\033[40m\]"
    local BGR="\[\033[41m\]"
    local BGG="\[\033[42m\]"
    local BGY="\[\033[43m\]"
    local BGB="\[\033[44m\]"
    local BGM="\[\033[45m\]"
    local BGC="\[\033[46m\]"
    local BGW="\[\033[47m\]"
    
    local UC=$W                 # user's color
    [ $UID -eq "0" ] && UC=$R   # root's color
    
    PS1="$TITLEBAR${EMK}[${UC}\u${EMK}@${UC}\h ${EMB}\${NEW_PWD}${EMK}]${UC}\\$ ${NONE}"

}
PROMPT_COMMAND=bash_prompt_command
bash_prompt
unset bash_prompt

### Bash stuff
export HISTCONTROL=ignoredups
export HISTSIZE=1000
export HISTFILESIZE=1000

### Bash options
#fix spelling
shopt -s cdspell
#makes bash append to history rather than overwrite
shopt -s histappend
#make bash check window after each command
shopt -s checkwinsize

### Misc
# disable XON/XOFF flow control (^s/^q) 
stty -ixon

# Tab complete for sudo
complete -cf sudo

#prevent overwriting files with cat
set -o noclobber

#stops ctrl+d from logging me out
#set -o ignoreeof

#Treat undefined variables as errors
set -o nounset
### Aliases
#safety! ohnoes.
alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'
alias mkdir='mkdir -p'
#colors
#alias ls='ls --color'
#alias ls='ls -hp --time-style=locale --color' 
alias ls='ls -G'
alias grep='grep --color=auto'
#alias ncmpc='ncmpc -c'
#unicode
#alias xterm='xterm -u8'
#alias screen='screen -U'
#sudo
#alias root='sudo su'
#alias pacman='sudo pacman'
#alias apt-get='sudo apt-get'
#alias aptitude='sudo aptitude'
#
alias cd..='cd ..'
alias more='less'
alias nano='nano -w'
alias vim='vim -X'
#alias xcomp='xcompmgr -cCfF -r7 -o.65 -l-10 -t-8 -D7'
alias servethis="python -c 'import SimpleHTTPServer; SimpleHTTPServer.test()'"
alias m='mate'
alias ss='./script/server'

###Console
#makes console terminal pretty
#slightly modified phraktured's
if [ "$TERM" = "linux" ]; then
    echo -en "\e]P0121212" #black
    echo -en "\e]P8474747" #darkgrey
    echo -en "\e]P1803232" #darkred
    echo -en "\e]P9982b2b" #red
    echo -en "\e]P25b762f" #darkgreen
    echo -en "\e]PA89b83f" #green
    echo -en "\e]P3AA9943" #dark yellow
    echo -en "\e]PBefef60" #yellow
    echo -en "\e]P4324c80" #darkblue
    echo -en "\e]PC2b4f98" #blue
    echo -en "\e]P55F5A90" #darkmagenta
    echo -en "\e]PD826ab1" #magenta
    echo -en "\e]P692b19e" #darkcyan
    echo -en "\e]PEa1cdcd" #cyan
    echo -en "\e]P7ffffff" #lightgrey
    echo -en "\e]PFdedede" #white
    clear #for background artifacting
fi


#more colors!
if [ -f ~/.dir_colors ]; then
            eval `dircolors ~/.dir_colors`
fi 
export EDITOR="/usr/bin/mate -w"

brogers /.bashrc

http://dotfiles.org/~brogers/.bashrc 
complete -C ~/bin/rake_tab_completion -o default rake
complete -C ~/bin/sake_tab_completion -o default sake

export RUBYOPT=rubygems


if [ -f ~/.LifehackerTerminalTweaks ]; then
  source ~/.LifehackerTerminalTweaks
fi

An interesting example of .bashrc with the ability to extract files from archive on the base of extention (Norton COmmander functionality ;-)

http://dotfiles.org/~joephantom/.bashrc 
joephantom /.bashrc 

extract () {
    if [ -f $1 ] ; then
        case $1 in
            *.tar.bz2)  tar xjf $1      ;;
            *.tar.gz)   tar xzf $1      ;;
            *.bz2)      bunzip2 $1      ;;
            *.rar)      unrar x $1      ;;
            *.gz)       gunzip $1       ;;
            *.tar)      tar xf $1       ;;
            *.tbz2)     tar xjf $1      ;;
            *.tgz)      tar xzf $1      ;;
            *.zip)      unzip $1        ;;
            *.Z)        uncompress $1   ;;
            *)          echo "'$1' cannot be extracted via extract()" ;;
        esac
    else
        echo "'$1' is not a valid file"
    fi
}
 
#
rmspaces() {
    ls | while read -r FILE
        do
        mv -v "$FILE" `echo $FILE | tr ' ' '_' | tr -d '[{}(),\!]' | tr -d "\'" | tr '[A-Z]' '[a-z]' | sed 's/_-_/_/g'`
        done
}
#
makepasswords() {
    perl <$%&()*^}));
        for (1..10) {
            print join "", map { \$a[rand @a] } (1..rand(3)+10);
            print qq{\n}
        }
EOPERL
}
 
#
alias ls='ls --color=auto'
#
#PS1="\[\e[36;1m\]\u @ \[\e[32;1m\]\H > \[\e[0m\]"
#
PS1='\[\033[0;36m\]\033(0l\033(B\[\033[0m\][\[\033[1;31m\]\u\[\033[0m\]]\[\033[0;36m\]\033(0q\033(B\[\033[0m\][\[\033[1;33m\]@\h\[\033[0m\]]\[\033[0;36m\]\033(0q\033(B\[\033[0m\][\[\033[0;37m\]\T\[\033[0m\]]\[\033[0;36m\]\033(0q\033(B\033(0q\033(B\033(0q\033(B\033(0q\033(B\033(0q\033(B\033(0q\033(B\033(0q\033(B\033(0q\033(B\[\033[0m\][\[\033[1;33m\]\w\[\033[0m\]]\n\[\033[0;36m\]\033(0m\033(B\[\033[0m\]>'
#
complete -cf sudo
alias pacs="pacsearch"

pacsearch () {
       echo -e "$(pacman -Ss $@ | sed \
       -e 's#core/.*#\\033[1;31m&\\033[0;37m#g' \
       -e 's#extra/.*#\\033[0;32m&\\033[0;37m#g' \
       -e 's#community/.*#\\033[1;35m&\\033[0;37m#g' \
       -e 's#^.*/.* [0-9].*#\\033[0;36m&\\033[0;37m#g' )"

A Sample .bashrc File

The ~/.bashrc file determines the behavior of interactive shells. A good look at this file can lead to a better understanding of Bash.

Emmanuel Rouat contributed the following very elaborate .bashrc file, written for a Linux system. He welcomes reader feedback on it.

Study the file carefully, and feel free to reuse code snippets and functions from it in your own .bashrc file or even in your scripts.

Example L-1. Sample .bashrc file
#=============================================================
#
# PERSONAL $HOME/.bashrc FILE for bash-3.0 (or later)
# By Emmanuel Rouat <no-email>
#
# Last modified: Sun Nov 30 16:27:45 CET 2008
# This file is read (normally) by interactive shells only.
# Here is the place to define your aliases, functions and
# other interactive features like your prompt.
#
# The majority of the code here assumes you are on a GNU 
# system (most likely a Linux box) and is based on code found
# on Usenet or internet. See for instance:
#
# http://tldp.org/LDP/abs/html/index.html
# http://www.caliban.org/bash/
# http://www.shelldorado.com/scripts/categories.html
# http://www.dotfiles.org/
#
# This bashrc file is a bit overcrowded -- remember it is just
# just an example. Tailor it to your needs.
#
#
#=============================================================

# --> Comments added by HOWTO author.


#-------------------------------------------------------------
# Source global definitions (if any)
#-------------------------------------------------------------


if [ -f /etc/bashrc ]; then
        . /etc/bashrc   # --> Read /etc/bashrc, if present.
fi

#-------------------------------------------------------------
# Automatic setting of $DISPLAY (if not set already).
# This works for linux - your mileage may vary. ... 
# The problem is that different types of terminals give
# different answers to 'who am i' (rxvt in particular can be
# troublesome).
# I have not found a 'universal' method yet.
#-------------------------------------------------------------

function get_xserver ()
{
    case $TERM in
       xterm )
            XSERVER=$(who am i | awk '{print $NF}' | tr -d ')''(' ) 
            # Ane-Pieter Wieringa suggests the following alternative:
            # I_AM=$(who am i)
            # SERVER=${I_AM#*(}
            # SERVER=${SERVER%*)}

            XSERVER=${XSERVER%%:*}
            ;;
        aterm | rxvt)
        # Find some code that works here. ...
            ;;
    esac  
}

if [ -z ${DISPLAY:=""} ]; then
    get_xserver
    if [[ -z ${XSERVER}  || ${XSERVER} == $(hostname) || \
      ${XSERVER} == "unix" ]]; then 
        DISPLAY=":0.0"          # Display on local host.
    else
        DISPLAY=${XSERVER}:0.0  # Display on remote host.
    fi
fi

export DISPLAY

#-------------------------------------------------------------
# Some settings
#-------------------------------------------------------------

ulimit -S -c 0          # Don't want any coredumps.
set -o notify
set -o noclobber
set -o ignoreeof
set -o nounset
#set -o xtrace          # Useful for debuging.

# Enable options:
shopt -s cdspell
shopt -s cdable_vars
shopt -s checkhash
shopt -s checkwinsize
shopt -s sourcepath
shopt -s no_empty_cmd_completion
shopt -s cmdhist
shopt -s histappend histreedit histverify
shopt -s extglob        # Necessary for programmable completion.

# Disable options:
shopt -u mailwarn
unset MAILCHECK         # Don't want my shell to warn me of incoming mail.


export TIMEFORMAT=$'\nreal %3R\tuser %3U\tsys %3S\tpcpu %P\n'
export HISTTIMEFORMAT="%H:%M > "
export HISTIGNORE="&:bg:fg:ll:h"
export HOSTFILE=$HOME/.hosts    # Put list of remote hosts in ~/.hosts ...



#-------------------------------------------------------------
# Greeting, motd etc...
#-------------------------------------------------------------

# Define some colors first:
red='\e[0;31m'
RED='\e[1;31m'
blue='\e[0;34m'
BLUE='\e[1;34m'
cyan='\e[0;36m'
CYAN='\e[1;36m'
NC='\e[0m'              # No Color
# --> Nice. Has the same effect as using "ansi.sys" in DOS.


# Looks best on a terminal with black background.....
echo -e "${CYAN}This is BASH ${RED}${BASH_VERSION%.*}\
${CYAN} - DISPLAY on ${RED}$DISPLAY${NC}\n"
date
if [ -x /usr/games/fortune ]; then
    /usr/games/fortune -s     # Makes our day a bit more fun.... :-)
fi

function _exit()        # Function to run upon exit of shell.
{
    echo -e "${RED}Hasta la vista, baby${NC}"
}
trap _exit EXIT


#-------------------------------------------------------------
# Shell Prompt
#-------------------------------------------------------------


if [[ "${DISPLAY%%:0*}" != "" ]]; then  
    HILIT=${red}   # remote machine: prompt will be partly red
else
    HILIT=${cyan}  # local machine: prompt will be partly cyan
fi

#  --> Replace instances of \W with \w in prompt functions below
#+ --> to get display of full path name.

function fastprompt()
{
    unset PROMPT_COMMAND
    case $TERM in
        *term | rxvt )
            PS1="${HILIT}[\h]$NC \W > \[\033]0;\${TERM} [\u@\h] \w\007\]" ;;
        linux )
            PS1="${HILIT}[\h]$NC \W > " ;;
        *)
            PS1="[\h] \W > " ;;
    esac
}


_powerprompt()
{
    LOAD=$(uptime|sed -e "s/.*: \([^,]*\).*/\1/" -e "s/ //g")
}

function powerprompt()
{

    PROMPT_COMMAND=_powerprompt
    case $TERM in
        *term | rxvt  )
            PS1="${HILIT}[\A - \$LOAD]$NC\n[\u@\h \#] \W > \
                 \[\033]0;\${TERM} [\u@\h] \w\007\]" ;;
        linux )
            PS1="${HILIT}[\A - \$LOAD]$NC\n[\u@\h \#] \W > " ;;
        * )
            PS1="[\A - \$LOAD]\n[\u@\h \#] \W > " ;;
    esac
}

powerprompt     # This is the default prompt -- might be slow.
                # If too slow, use fastprompt instead. ...

#===============================================================
#
# ALIASES AND FUNCTIONS
#
# Arguably, some functions defined here are quite big.
# If you want to make this file smaller, these functions can
# be converted into scripts and removed from here.
#
# Many functions were taken (almost) straight from the bash-2.04
# examples.
#
#===============================================================

#-------------------
# Personnal Aliases
#-------------------

alias rm='rm -i'
alias cp='cp -i'
alias mv='mv -i'
# -> Prevents accidentally clobbering files.
alias mkdir='mkdir -p'

alias h='history'
alias j='jobs -l'
alias which='type -a'
alias ..='cd ..'
alias path='echo -e ${PATH//:/\\n}'
alias libpath='echo -e ${LD_LIBRARY_PATH//:/\\n}'
alias print='/usr/bin/lp -o nobanner -d $LPDEST'
            # Assumes LPDEST is defined (default printer)
alias pjet='enscript -h -G -fCourier9 -d $LPDEST'
            # Pretty-print using enscript

alias du='du -kh'       # Makes a more readable output.
alias df='df -kTh'

#-------------------------------------------------------------
# The 'ls' family (this assumes you use a recent GNU ls)
#-------------------------------------------------------------
alias ll="ls -l --group-directories-first"
alias ls='ls -hF --color'  # add colors for filetype recognition
alias la='ls -Al'          # show hidden files
alias lx='ls -lXB'         # sort by extension
alias lk='ls -lSr'         # sort by size, biggest last
alias lc='ls -ltcr'        # sort by and show change time, most recent last
alias lu='ls -ltur'        # sort by and show access time, most recent last
alias lt='ls -ltr'         # sort by date, most recent last
alias lm='ls -al |more'    # pipe through 'more'
alias lr='ls -lR'          # recursive ls
alias tree='tree -Csu'     # nice alternative to 'recursive ls'

# If your version of 'ls' doesn't support --group-directories-first try this:
# function ll(){ ls -l "$@"| egrep "^d" ; ls -lXB "$@" 2>&-| \
#                egrep -v "^d|total "; }


#-------------------------------------------------------------
# tailoring 'less'
#-------------------------------------------------------------

alias more='less'
export PAGER=less
export LESSCHARSET='latin1'
export LESSOPEN='|/usr/bin/lesspipe.sh %s 2>&-'
   # Use this if lesspipe.sh exists
export LESS='-i -N -w  -z-4 -g -e -M -X -F -R -P%t?f%f \
:stdin .?pb%pb\%:?lbLine %lb:?bbByte %bb:-...'


#-------------------------------------------------------------
# spelling typos - highly personnal and keyboard-dependent :-)
#-------------------------------------------------------------

alias xs='cd'
alias vf='cd'
alias moer='more'
alias moew='more'
alias kk='ll'


#-------------------------------------------------------------
# A few fun ones
#-------------------------------------------------------------


function xtitle()      # Adds some text in the terminal frame.
{
    case "$TERM" in
        *term | rxvt)
            echo -n -e "\033]0;$*\007" ;;
        *)  
            ;;
    esac
}

# aliases that use xtitle
alias top='xtitle Processes on $HOST && top'
alias make='xtitle Making $(basename $PWD) ; make'
alias ncftp="xtitle ncFTP ; ncftp"

# .. and functions
function man()
{
    for i ; do
        xtitle The $(basename $1|tr -d .[:digit:]) manual
        command man -F -a "$i"
    done
}


#-------------------------------------------------------------
# Make the following commands run in background automatically:
#-------------------------------------------------------------

function te()  # Wrapper around xemacs/gnuserv ...
{
    if [ "$(gnuclient -batch -eval t 2>&-)" == "t" ]; then
        gnuclient -q "$@";
    else
        ( xemacs "$@" &);
    fi
}

function soffice() { command soffice "$@" & }
function firefox() { command firefox "$@" & }
function xpdf() { command xpdf "$@" & }


#-------------------------------------------------------------
# File & string-related functions:
#-------------------------------------------------------------


# Find a file with a pattern in name:
function ff() { find . -type f -iname '*'$*'*' -ls ; }

# Find a file with pattern $1 in name and Execute $2 on it:
function fe()
{ find . -type f -iname '*'${1:-}'*' -exec ${2:-file} {} \;  ; }

# Find a pattern in a set of files and highlight them:
# (needs a recent version of egrep)
function fstr()
{
    OPTIND=1
    local case=""
    local usage="fstr: find string in files.
Usage: fstr [-i] \"pattern\" [\"filename pattern\"] "
    while getopts :it opt
    do
        case "$opt" in
        i) case="-i " ;;
        *) echo "$usage"; return;;
        esac
    done
    shift $(( $OPTIND - 1 ))
    if [ "$#" -lt 1 ]; then
        echo "$usage"
        return;
    fi
    find . -type f -name "${2:-*}" -print0 | \
    xargs -0 egrep --color=always -sn ${case} "$1" 2>&- | more 

}

function cuttail() # cut last n lines in file, 10 by default
{
    nlines=${2:-10}
    sed -n -e :a -e "1,${nlines}!{P;N;D;};N;ba" $1
}

function lowercase()  # move filenames to lowercase
{
    for file ; do
        filename=${file##*/}
        case "$filename" in
        */*) dirname==${file%/*} ;;
        *) dirname=.;;
        esac
        nf=$(echo $filename | tr A-Z a-z)
        newname="${dirname}/${nf}"
        if [ "$nf" != "$filename" ]; then
            mv "$file" "$newname"
            echo "lowercase: $file --> $newname"
        else
            echo "lowercase: $file not changed."
        fi
    done
}


function swap()  # Swap 2 filenames around, if they exist
{                #(from Uzi's bashrc).
    local TMPFILE=tmp.$$ 

    [ $# -ne 2 ] && echo "swap: 2 arguments needed" && return 1
    [ ! -e $1 ] && echo "swap: $1 does not exist" && return 1
    [ ! -e $2 ] && echo "swap: $2 does not exist" && return 1

    mv "$1" $TMPFILE 
    mv "$2" "$1"
    mv $TMPFILE "$2"
}

function extract()      # Handy Extract Program.
{
     if [ -f $1 ] ; then
         case $1 in
             *.tar.bz2)   tar xvjf $1     ;;
             *.tar.gz)    tar xvzf $1     ;;
             *.bz2)       bunzip2 $1      ;;
             *.rar)       unrar x $1      ;;
             *.gz)        gunzip $1       ;;
             *.tar)       tar xvf $1      ;;
             *.tbz2)      tar xvjf $1     ;;
             *.tgz)       tar xvzf $1     ;;
             *.zip)       unzip $1        ;;
             *.Z)         uncompress $1   ;;
             *.7z)        7z x $1         ;;
             *)           echo "'$1' cannot be extracted via >extract<" ;;
         esac
     else
         echo "'$1' is not a valid file"
     fi
}

#-------------------------------------------------------------
# Process/system related functions:
#-------------------------------------------------------------


function my_ps() { ps $@ -u $USER -o pid,%cpu,%mem,bsdtime,command ; }
function pp() { my_ps f | awk '!/awk/ && $0~var' var=${1:-".*"} ; }


function killps()                 # Kill by process name.
{
    local pid pname sig="-TERM"   # Default signal.
    if [ "$#" -lt 1 ] || [ "$#" -gt 2 ]; then
        echo "Usage: killps [-SIGNAL] pattern"
        return;
    fi
    if [ $# = 2 ]; then sig=$1 ; fi
    for pid in $(my_ps| awk '!/awk/ && $0~pat { print $1 }' pat=${!#} ) ; do
        pname=$(my_ps | awk '$1~var { print $5 }' var=$pid )
        if ask "Kill process $pid <$pname> with signal $sig?"
            then kill $sig $pid
        fi
    done
}

function my_ip() # Get IP adresses.
{
    MY_IP=$(/sbin/ifconfig ppp0 | awk '/inet/ { print $2 } ' | \
sed -e s/addr://)
    MY_ISP=$(/sbin/ifconfig ppp0 | awk '/P-t-P/ { print $3 } ' | \
sed -e s/P-t-P://)
}

function ii()   # Get current host related info.
{
    echo -e "\nYou are logged on ${RED}$HOST"
    echo -e "\nAdditionnal information:$NC " ; uname -a
    echo -e "\n${RED}Users logged on:$NC " ; w -h
    echo -e "\n${RED}Current date :$NC " ; date
    echo -e "\n${RED}Machine stats :$NC " ; uptime
    echo -e "\n${RED}Memory stats :$NC " ; free
    my_ip 2>&- ;
    echo -e "\n${RED}Local IP Address :$NC" ; echo ${MY_IP:-"Not connected"}
    echo -e "\n${RED}ISP Address :$NC" ; echo ${MY_ISP:-"Not connected"}
    echo -e "\n${RED}Open connections :$NC "; netstat -pan --inet;
    echo
}

#-------------------------------------------------------------
# Misc utilities:
#-------------------------------------------------------------

function repeat()       # Repeat n times command.
{
    local i max
    max=$1; shift;
    for ((i=1; i <= max ; i++)); do  # --> C-like syntax
        eval "$@";
    done
}


function ask()          # See 'killps' for example of use.
{
    echo -n "$@" '[y/n] ' ; read ans
    case "$ans" in
        y*|Y*) return 0 ;;
        *) return 1 ;;
    esac
}

function corename()   # Get name of app that created a corefile.
{ 
    for file ; do
        echo -n $file : ; gdb --core=$file --batch | head -1
    done 
}




#=========================================================================
# PROGRAMMABLE COMPLETION - ONLY SINCE BASH-2.04
# Most are taken from the bash 2.05 documentation and from Ian McDonald's
# 'Bash completion' package (http://www.caliban.org/bash/#completion).
# You will in fact need bash more recent than 3.0 for some features.
#=========================================================================

if [ "${BASH_VERSION%.*}" \< "3.0" ]; then
    echo "You will need to upgrade to version 3.0 \
for full programmable completion features."
    return
fi

shopt -s extglob         # Necessary,
#set +o nounset          # otherwise some completions will fail.

complete -A hostname   rsh rcp telnet rlogin r ftp ping disk
complete -A export     printenv
complete -A variable   export local readonly unset
complete -A enabled    builtin
complete -A alias      alias unalias
complete -A function   function
complete -A user       su mail finger

complete -A helptopic  help     # Currently, same as builtins.
complete -A shopt      shopt
complete -A stopped -P '%' bg
complete -A job -P '%'     fg jobs disown

complete -A directory  mkdir rmdir
complete -A directory   -o default cd

# Compression
complete -f -o default -X '*.+(zip|ZIP)'  zip
complete -f -o default -X '!*.+(zip|ZIP)' unzip
complete -f -o default -X '*.+(z|Z)'      compress
complete -f -o default -X '!*.+(z|Z)'     uncompress
complete -f -o default -X '*.+(gz|GZ)'    gzip
complete -f -o default -X '!*.+(gz|GZ)'   gunzip
complete -f -o default -X '*.+(bz2|BZ2)'  bzip2
complete -f -o default -X '!*.+(bz2|BZ2)' bunzip2
complete -f -o default -X '!*.+(zip|ZIP|z|Z|gz|GZ|bz2|BZ2)' extract


# Documents - Postscript,pdf,dvi.....
complete -f -o default -X '!*.+(ps|PS)'  gs ghostview ps2pdf ps2ascii
complete -f -o default -X '!*.+(dvi|DVI)' dvips dvipdf xdvi dviselect dvitype
complete -f -o default -X '!*.+(pdf|PDF)' acroread pdf2ps
complete -f -o default -X \
'!*.@(@(?(e)ps|?(E)PS|pdf|PDF)?(.gz|.GZ|.bz2|.BZ2|.Z))' gv ggv
complete -f -o default -X '!*.texi*' makeinfo texi2dvi texi2html texi2pdf
complete -f -o default -X '!*.tex' tex latex slitex
complete -f -o default -X '!*.lyx' lyx
complete -f -o default -X '!*.+(htm*|HTM*)' lynx html2ps
complete -f -o default -X \
'!*.+(doc|DOC|xls|XLS|ppt|PPT|sx?|SX?|csv|CSV|od?|OD?|ott|OTT)' soffice

# Multimedia
complete -f -o default -X \
'!*.+(gif|GIF|jp*g|JP*G|bmp|BMP|xpm|XPM|png|PNG)' xv gimp ee gqview
complete -f -o default -X '!*.+(mp3|MP3)' mpg123 mpg321
complete -f -o default -X '!*.+(ogg|OGG)' ogg123
complete -f -o default -X \
'!*.@(mp[23]|MP[23]|ogg|OGG|wav|WAV|pls|m3u|xm|mod|s[3t]m|it|mtm|ult|flac)' xmms
complete -f -o default -X \
'!*.@(mp?(e)g|MP?(E)G|wma|avi|AVI|asf|vob|VOB|bin|dat|vcd|\
ps|pes|fli|viv|rm|ram|yuv|mov|MOV|qt|QT|wmv|mp3|MP3|ogg|OGG|\
ogm|OGM|mp4|MP4|wav|WAV|asx|ASX)' xine



complete -f -o default -X '!*.pl'  perl perl5


# This is a 'universal' completion function - it works when commands have
# a so-called 'long options' mode , ie: 'ls --all' instead of 'ls -a'
# Needs the '-o' option of grep
#  (try the commented-out version if not available).

# First, remove '=' from completion word separators
# (this will allow completions like 'ls --color=auto' to work correctly).

COMP_WORDBREAKS=${COMP_WORDBREAKS/=/}


_get_longopts() 
{ 
    #$1 --help | sed  -e '/--/!d' -e 's/.*--\([^[:space:].,]*\).*/--\1/'| \
#grep ^"$2" |sort -u ;
    $1 --help | grep -o -e "--[^[:space:].,]*" | grep -e "$2" |sort -u 
}

_longopts()
{
    local cur
    cur=${COMP_WORDS[COMP_CWORD]}

    case "${cur:-*}" in
       -*)      ;;
        *)      return ;;
    esac

    case "$1" in
      \~*)      eval cmd="$1" ;;
        *)      cmd="$1" ;;
    esac
    COMPREPLY=( $(_get_longopts ${1} ${cur} ) )
}
complete  -o default -F _longopts configure bash
complete  -o default -F _longopts wget id info a2ps ls recode

_tar()
{
    local cur ext regex tar untar

    COMPREPLY=()
    cur=${COMP_WORDS[COMP_CWORD]}

    # If we want an option, return the possible long options.
    case "$cur" in
        -*)     COMPREPLY=( $(_get_longopts $1 $cur ) ); return 0;;
    esac

    if [ $COMP_CWORD -eq 1 ]; then
        COMPREPLY=( $( compgen -W 'c t x u r d A' -- $cur ) )
        return 0
    fi

    case "${COMP_WORDS[1]}" in
        ?(-)c*f)
            COMPREPLY=( $( compgen -f $cur ) )
            return 0
            ;;
            +([^Izjy])f)
            ext='tar'
            regex=$ext
            ;;
        *z*f)
            ext='tar.gz'
            regex='t\(ar\.\)\(gz\|Z\)'
            ;;
        *[Ijy]*f)
            ext='t?(ar.)bz?(2)'
            regex='t\(ar\.\)bz2\?'
            ;;
        *)
            COMPREPLY=( $( compgen -f $cur ) )
            return 0
            ;;

    esac

    if [[ "$COMP_LINE" == tar*.$ext' '* ]]; then
        # Complete on files in tar file.
        #
        # Get name of tar file from command line.
        tar=$( echo "$COMP_LINE" | \
               sed -e 's|^.* \([^ ]*'$regex'\) .*$|\1|' )
        # Devise how to untar and list it.
        untar=t${COMP_WORDS[1]//[^Izjyf]/}

        COMPREPLY=( $( compgen -W "$( echo $( tar $untar $tar \
                    2>/dev/null ) )" -- "$cur" ) )
        return 0

    else
        # File completion on relevant files.
        COMPREPLY=( $( compgen -G $cur\*.$ext ) )

    fi

    return 0

}

complete -F _tar -o default tar

_make()
{
    local mdef makef makef_dir="." makef_inc gcmd cur prev i;
    COMPREPLY=();
    cur=${COMP_WORDS[COMP_CWORD]};
    prev=${COMP_WORDS[COMP_CWORD-1]};
    case "$prev" in
        -*f)
            COMPREPLY=($(compgen -f $cur ));
            return 0
        ;;
    esac;
    case "$cur" in
        -*)
            COMPREPLY=($(_get_longopts $1 $cur ));
            return 0
        ;;
    esac;

    # make reads `GNUmakefile', then `makefile', then `Makefile'
    if [ -f ${makef_dir}/GNUmakefile ]; then
        makef=${makef_dir}/GNUmakefile
    elif [ -f ${makef_dir}/makefile ]; then
        makef=${makef_dir}/makefile
    elif [ -f ${makef_dir}/Makefile ]; then
        makef=${makef_dir}/Makefile
    else
        makef=${makef_dir}/*.mk        # Local convention.
    fi


    # Before we scan for targets, see if a Makefile name was
    # specified with -f ...
    for (( i=0; i < ${#COMP_WORDS[@]}; i++ )); do
        if [[ ${COMP_WORDS[i]} == -f ]]; then
           # eval for tilde expansion
           eval makef=${COMP_WORDS[i+1]}
           break
        fi
    done
    [ ! -f $makef ] && return 0

    # deal with included Makefiles
    makef_inc=$( grep -E '^-?include' $makef | \
    sed -e "s,^.* ,"$makef_dir"/," )
    for file in $makef_inc; do
        [ -f $file ] && makef="$makef $file"
    done


    # If we have a partial word to complete, restrict completions to
    # matches of that word.
    if [ -n "$cur" ]; then gcmd='grep "^$cur"' ; else gcmd=cat ; fi

    COMPREPLY=( $( awk -F':' '/^[a-zA-Z0-9][^$#\/\t=]*:([^=]|$)/ \
                                {split($1,A,/ /);for(i in A)print A[i]}' \
                                $makef 2>/dev/null | eval $gcmd  ))

}

complete -F _make -X '+($*|*.[cho])' make gmake pmake




_killall()
{
    local cur prev
    COMPREPLY=()
    cur=${COMP_WORDS[COMP_CWORD]}

    # get a list of processes (the first sed evaluation
    # takes care of swapped out processes, the second
    # takes care of getting the basename of the process)
    COMPREPLY=( $( /usr/bin/ps -u $USER -o comm  | \
        sed -e '1,1d' -e 's#[]\[]##g' -e 's#^.*/##'| \
        awk '{if ($0 ~ /^'$cur'/) print $0}' ))

    return 0
}

complete -F _killall killall killps



# A meta-command completion function for commands like sudo(8), which need to
# first complete on a command, then complete according to that command's own
# completion definition - currently not quite foolproof,
# but still quite useful (By Ian McDonald, modified by me).


_meta_comp()
{
    local cur func cline cspec

    COMPREPLY=()
    cur=${COMP_WORDS[COMP_CWORD]}
    cmdline=${COMP_WORDS[@]}
    if [ $COMP_CWORD = 1 ]; then  
         COMPREPLY=( $( compgen -c $cur ) )
    else
        cmd=${COMP_WORDS[1]}            # Find command.
        cspec=$( complete -p ${cmd} )   # Find spec of that command.

        # COMP_CWORD and COMP_WORDS() are not read-only,
        # so we can set them before handing off to regular
        # completion routine:
        # Get current command line minus initial command,
        cline="${COMP_LINE#$1 }"
        # split current command line tokens into array,
        COMP_WORDS=( $cline )
        # set current token number to 1 less than now.
        COMP_CWORD=$(( $COMP_CWORD - 1 ))
        # If current arg is empty, add it to COMP_WORDS array
        # (otherwise that information will be lost).
        if [ -z $cur ]; then COMP_WORDS[COMP_CWORD]=""  ; fi

        if [ "${cspec%%-F *}" != "${cspec}" ]; then
      # if -F then get function:
            func=${cspec#*-F }
            func=${func%% *}
            eval $func $cline   # Evaluate it.
        else
            func=$( echo $cspec | sed -e 's/^complete//' -e 's/[^ ]*$//' )
            COMPREPLY=( $( eval compgen $func $cur ) )
        fi

    fi
    
}


complete -o default -F _meta_comp nohup \
eval exec trace truss strace sotruss gdb
complete -o default -F _meta_comp command type which man nice time

# Local Variables:
# mode:shell-script
# sh-shell:bash
# End:

Bash Shell PS1: 10 Examples to Make Your Linux Prompt like Angelina Jolie

3. Display output of any Linux command in the prompt

You can display output of any Linux command in the prompt. The following example displays three items separated by | (pipe) in the command prompt:

ramesh@dev-db ~> kernel_version=$(uname -r)
ramesh@dev-db ~> export PS1="\!|\h|$kernel_version|\$?> "
473|dev-db|2.6.25-14.fc9.i686|0>

4. Change foreground color of the prompt

Display prompt in blue color, along with username, host and current directory information

$ export PS1="\e[0;34m\u@\h \w> \e[m"
[Note: This is for light blue prompt]

$ export PS1="\e[1;34m\u@\h \w> \e[m"
[Note: This is for dark blue prompt]

Color Code Table:

Black 0;30
Blue 0;34
Green 0;32
Cyan 0;36
Red 0;31
Purple 0;35
Brown 0;33
[Note: Replace 0 with 1 for dark color]

Make the color change permanent by adding the following lines to .bash_profile or .bashrc

STARTCOLOR='\e[0;34m';
ENDCOLOR="\e[0m"
export PS1="$STARTCOLOR\u@\h \w> $ENDCOLOR"

5. Change background color of the prompt

Change the background color by specifying \e[{code}m in the PS1 prompt as shown below.

$ export PS1="\e[47m\u@\h \w> \e[m"
[Note: This is for Light Gray background]

Combination of background and foreground

export PS1="\e[0;34m\e[47m\u@\h \w> \e[m"
[Note: This is for Light Blue foreground and Light Gray background]

Add the following to the .bash_profile or .bashrc to make the above background and foreground color permanent.

STARTFGCOLOR='\e[0;34m';
STARTBGCOLOR="\e[47m"
ENDCOLOR="\e[0m"
export PS1="$STARTFGCOLOR$STARTBGCOLOR\u@\h \w> $ENDCOLOR"

Play around by using the following background color and choose the one that suites your taste:

6. Display multiple colors in the prompt

You can also display multiple colors in the same prompt. Add the following function to .bash_profile

function prompt {
  local BLUE="\[\033[0;34m\]"
  local DARK_BLUE="\[\033[1;34m\]"
  local RED="\[\033[0;31m\]"
  local DARK_RED="\[\033[1;31m\]"
  local NO_COLOR="\[\033[0m\]"
  case $TERM in
    xterm*|rxvt*)
      TITLEBAR='\[\033]0;\u@\h:\w\007\]'
      ;;
    *)
      TITLEBAR=""
      ;;
  esac
  PS1="\u@\h [\t]> "
  PS1="${TITLEBAR}\
  $BLUE\u@\h $RED[\t]>$NO_COLOR "
  PS2='continue-> '
  PS4='$0.$LINENO+ '
}

You can re-login for the changes to take effect or source the .bash_profile as shown below.

$. ./.bash_profile
$ prompt
ramesh@dev-db [13:02:13]>

7. Change the prompt color using tput

You can also change color of the PS1 prompt using tput as shown below:

$ export PS1="\[$(tput bold)$(tput setb 4)$(tput setaf 7)\]\u@\h:\w $ \[$(tput sgr0)\]"

tput Color Capabilities:

tput Text Mode Capabilities:

Color Code for tput:

[Dec 9, 2007] Cool Solutions Bash - Making use of your .bashrc file

Too big but some ideas probably can be borrowed...

Details

I was playing with my .bashrc file again, and was once again impressed by how you can tweak Linux to do what YOU want it to do so easily. I am sure there are tons of other tweaks you can do to your .bashrc file, but I really like some of mine, and thought I would share them. Some of the alias's I created, some I found on the net, and some things in my .bashrc file are just there for fun, like the "# WELCOME SCREEN", although it does serve a purpose for me at the same time, it might not be something everyone would want or need.

For those that don't know what a .bashrc file does: "The ~/.bashrc file determines the behavior of interactive shells." Quoted From: The Advanced Bash Scripting Guide 

Basically , it allows you to create shortcuts (alias's) and interactive programs (functions) that run on the startup of the bash shell or that are used when running an interactive shell. For example, it's much easier to just type: ebrc instead of pico ~/.bashrc (I used the alias ebrc , and it stands for "Edit Bash RC file". I could have also aliased it to just use one letter, making it a VERY fast short cut. The bashrc file allows you to create alias's (shortcuts) to almost anything you want. My list is pretty long, but I'm sure there is someone with a longer list ;)

I have my .bashrc file setup in sections. The following is the breakdown by section of how I keep my list of alias's and functions separated. This is just how I do this, your .bashrc file can be modified to suit YOUR needs, that's the interesting part about the .bashrc file. It's VERY customizable and very easy to change.

Header (So I know when i modified it last and what i was running it on)
Exports (So I can set history size, paths , editors, define colors, etc,)
Sourced Alias's (So I can find those hidden alias's faster)
Workstation Alias's (so i can ssh to local machines quickly)
Remote Server Alias's (so i can ssh to remote servers easily)
Script Alias's (quick links to some of my bashscripts)
Hardware control alias's (so I can control cd/dvd/scanners/audio/etc)
Modified commands (Alias's to normal linux commands with special flags)
Chmod Alias's (makes changing permissions faster)
Alias's for GUI programs (start firefox, etc from command line)
Alias's for xterm and others (open xterm with special settings)
Alias's for Lynx (open lynx with urls - kind of a bash bookmark ;) )
UNused Alias's (Alias's that aren't in use on the system, but that i might use later)
Special functions (more of a function than just an alias..it goes here)
Notes (that should be self explanatory ;) )
Welcome Screen (code to make my bash shell display some stuff as it starts up)

That's how I lay out my .bashrc files. It may not be perfect, but it works well for me. I like making changes in just my .bashrc file and not the global files. I like the .bashrc file because you don't need root permissions to make changes that make your life easier at the bash shell.

The following is my .bashrc file (with some things obviously commented out for security... but most of it should be self explanatory). Anyone with comments/suggestions/ideas feel free to let me know. I'm always looking for new and interesting things to do with the .bashrc file.

Want to know what alias's your bash shell has? Simply type the word alias at the command line. The shell will then print out the list of active alias's to the standard output (normally your screen).

#######################################################
# Dave Crouse's .bashrc file
# www.bashscripts.org
# www.usalug.org
#
# Last Modified 04-08-2006
# Running on OpenSUSE 10
#######################################################


# EXPORTS
#######################################################

PATH=$PATH:/usr/lib/festival/ ;export PATH
export PS1="[\[\033[1;34m\w\[\033[0m]\n[\t \u]$ "
export EDITOR=/usr/bin/pico
export HISTFILESIZE=3000 # the bash history should save 3000 commands
export HISTCONTROL=ignoredups #don't put duplicate lines in the history.
alias hist='history | grep $1' #Requires one input

# Define a few Color's
BLACK='\e[0;30m'
BLUE='\e[0;34m'
GREEN='\e[0;32m'
CYAN='\e[0;36m'
RED='\e[0;31m'
PURPLE='\e[0;35m'
BROWN='\e[0;33m'
LIGHTGRAY='\e[0;37m'
DARKGRAY='\e[1;30m'
LIGHTBLUE='\e[1;34m'
LIGHTGREEN='\e[1;32m'
LIGHTCYAN='\e[1;36m'
LIGHTRED='\e[1;31m'
LIGHTPURPLE='\e[1;35m'
YELLOW='\e[1;33m'
WHITE='\e[1;37m'
NC='\e[0m'              # No Color
# Sample Command using color: echo -e "${CYAN}This is BASH
${RED}${BASH_VERSION%.*}${CYAN} - DISPLAY on ${RED}$DISPLAY${NC}\n"


# SOURCED ALIAS'S AND SCRIPTS
#######################################################

### Begin insertion of bbips alias's ###
source ~/.bbips/commandline/bbipsbashrc
### END bbips alias's ###

# Source global definitions
if [ -f /etc/bashrc ]; then
    . /etc/bashrc
fi

# enable programmable completion features
if [ -f /etc/bash_completion ]; then
    . /etc/bash_completion
fi


# ALIAS'S OF ALL TYPES SHAPES AND FORMS ;)
#######################################################

# Alias's to local workstations
alias tom='ssh 192.168.2.102 -l root'
alias jason='ssh 192.168.2.103 -l root'
alias randy='ssh 192.168.2.104 -l root'
alias bob='ssh 192.168.2.105 -l root'
alias don='ssh 192.168.2.106 -l root'
alias counter='ssh 192.168.2.107 -l root'

# ALIAS TO REMOTE SERVERS
alias ANYNAMEHERE='ssh YOURWEBSITE.com -l USERNAME -p PORTNUMBERHERE'
# My server info removed from above for obvious reasons ;)

# Alias's to TN5250 programs. AS400 access commands.
alias d1='xt5250 env.TERM = IBM-3477-FC env.DEVNAME=D1 192.168.2.5 &'
alias d2='xt5250 env.TERM = IBM-3477-FC env.DEVNAME=D2 192.168.2.5 &'
alias tn5250j='nohup java -jar /home/crouse/tn5250j/lib/tn5250j.jar
2>>error.log &'

# Alias's to some of my BashScripts
alias bics='sh /home/crouse/scripts/bics/bics.sh'
alias backup='sh /home/crouse/scripts/usalugbackup.sh'
alias calc='sh /home/crouse/scripts/bashcalc.sh'
alias makepdf='sh /home/crouse/scripts/makepdf.sh'
alias phonebook='sh /home/crouse/scripts/PHONEBOOK/baps.sh'
alias pb='sh /home/crouse/scripts/PHONEBOOK/baps.sh'
alias ppe='/home/crouse/scripts/passphraseencryption.sh'
alias scripts='cd /home/crouse/scripts'

# Alias's to control hardware
alias cdo='eject /dev/cdrecorder'
alias cdc='eject -t /dev/cdrecorder'
alias dvdo='eject /dev/dvd'
alias dvdc='eject -t /dev/dvd'
alias scan='scanimage -L'
alias playw='for i in *.wav; do play $i; done'
alias playo='for i in *.ogg; do play $i; done'
alias playm='for i in *.mp3; do play $i; done'
alias copydisk='dd if=/dev/dvd of=/dev/cdrecorder' # Copies bit by bit
from dvd to cdrecorder drives.
alias dvdrip='vobcopy -i /dev/dvd/ -o ~/DVDs/ -l'

# Alias's to modified commands
alias ps='ps auxf'
alias home='cd ~'
alias pg='ps aux | grep'  #requires an argument
alias un='tar -zxvf'
alias mountedinfo='df -hT'
alias ping='ping -c 10'
alias openports='netstat -nape --inet'
alias ns='netstat -alnp --protocol=inet | grep -v CLOSE_WAIT | cut
-c-6,21-94 | tail +2'
alias du1='du -h --max-depth=1'
alias da='date "+%Y-%m-%d %A    %T %Z"'
alias ebrc='pico ~/.bashrc'

# Alias to multiple ls commands
alias la='ls -Al'               # show hidden files
alias ls='ls -aF --color=always' # add colors and file type extensions
alias lx='ls -lXB'              # sort by extension
alias lk='ls -lSr'              # sort by size
alias lc='ls -lcr'      # sort by change time
alias lu='ls -lur'      # sort by access time
alias lr='ls -lR'               # recursive ls
alias lt='ls -ltr'              # sort by date
alias lm='ls -al |more'         # pipe through 'more'

# Alias chmod commands
alias mx='chmod a+x'
alias 000='chmod 000'
alias 644='chmod 644'
alias 755='chmod 755'

# Alias Shortcuts to graphical programs.
alias kwrite='kwrite 2>/dev/null &'
alias firefox='firefox 2>/dev/null &'
alias gaim='gaim 2>/dev/null &'
alias kate='kate 2>/dev/null &'
alias suk='kdesu konqueror 2>/dev/null &'

# Alias xterm and aterm
alias term='xterm -bg AntiqueWhite -fg Black &'
alias termb='xterm -bg AntiqueWhite -fg NavyBlue &'
alias termg='xterm -bg AntiqueWhite -fg OliveDrab &'
alias termr='xterm -bg AntiqueWhite -fg DarkRed &'
alias aterm='aterm -ls -fg gray -bg black'
alias xtop='xterm -fn 6x13 -bg LightSlateGray -fg black -e top &'
alias xsu='xterm -fn 7x14 -bg DarkOrange4 -fg white -e su &'

# Alias for lynx web browser
alias bbc='lynx -term=vt100 http://news.bbc.co.uk/text_only.stm'
alias nytimes='lynx -term=vt100 http://nytimes.com'
alias dmregister='lynx -term=vt100 http://desmoinesregister.com'


# SOME OF MY UNUSED ALIAS's
#######################################################

# alias d=`echo "Good Morning Dave. today's date is" | festival --tts;
date +'%A %B %e' | festival --tts`
# alias shrink84='/home/crouse/shrink84/shrink84.sh'
# alias tl='tail -f /var/log/apache/access.log'
# alias te='tail -f /var/log/apache/error.log'


# SPECIAL FUNCTIONS
#######################################################

netinfo ()
{
echo "--------------- Network Information ---------------"
/sbin/ifconfig | awk /'inet addr/ {print $2}'
echo ""
/sbin/ifconfig | awk /'Bcast/ {print $3}'
echo ""
/sbin/ifconfig | awk /'inet addr/ {print $4}'

# /sbin/ifconfig | awk /'HWaddr/ {print $4,$5}'
echo "---------------------------------------------------"
}

spin ()
{
echo -ne "${RED}-"
echo -ne "${WHITE}\b|"
echo -ne "${BLUE}\bx"
sleep .02
echo -ne "${RED}\b+${NC}"
}

scpsend ()
{
scp -P PORTNUMBERHERE "$@"
[email protected]:/var/www/html/pathtodirectoryonremoteserver/;
}


# NOTES
#######################################################

# To temporarily bypass an alias, we preceed the command with a \
# EG:  the ls command is aliased, but to use the normal ls command you would
# type \ls

# mount -o loop /home/crouse/NAMEOFISO.iso /home/crouse/ISOMOUNTDIR/
# umount /home/crouse/NAMEOFISO.iso
# Both commands done as root only.


# WELCOME SCREEN
#######################################################

clear
for i in `seq 1 15` ; do spin; done ;echo -ne "${WHITE} USA Linux Users
Group ${NC}"; for i in `seq 1 15` ; do spin; done ;echo "";
echo -e ${LIGHTBLUE}`cat /etc/SUSE-release` ;
echo -e "Kernel Information: " `uname -smr`;
echo -e ${LIGHTBLUE}`bash --version`;echo ""
echo -ne "Hello $USER today is "; date
echo -e "${WHITE}"; cal ; echo "";
echo -ne "${CYAN}";netinfo;
mountedinfo ; echo ""
echo -ne "${LIGHTBLUE}Uptime for this computer is ";uptime | awk /'up/
{print $3,$4}'
for i in `seq 1 15` ; do spin; done ;echo -ne "${WHITE} http://usalug.org
${NC}"; for i in `seq 1 15` ; do spin; done ;echo "";
echo ""; echo ""The following belong under the "function" section in my .bashrc. Useable as seperate programs, I've integrated them simply as functions for my .bashrc file in order to make them quick to use and easy to modify and find. These are functions that are used to symetrically encrypt and to decrypt files and messages. Some are completely command line, and the last two create gui interfaces to locate the files to encrypt/decrypt. If you create a program out of the functions creating a link via a shortcut/icon on the desktop would create a completely gui based interface to locate and encrypt/decrypt files. Either way, it's an easy way to use gpg.

Requires: zenity, gpg

################### Begin gpg functions ##################
encrypt ()
{
# Use ascii armor
gpg -ac --no-options "$1"
}

bencrypt ()
{
# No ascii armor
# Encrypt binary data. jpegs/gifs/vobs/etc.
gpg -c --no-options "$1"
}

decrypt ()
{
gpg --no-options "$1"
}

pe ()
{
# Passphrase encryption program
# Created by Dave Crouse 01-13-2006
# Reads input from text editor and encrypts to screen.
clear
echo "         Passphrase Encryption Program";
echo "--------------------------------------------------"; echo "";
which $EDITOR &>/dev/null
 if [ $? != "0" ];
     then
     echo "It appears that you do not have a text editor set in your
.bashrc file.";
     echo "What editor would you like to use ? " ;
     read EDITOR ; echo "";
 fi
echo "Enter the name/comment for this message :"
read comment
$EDITOR passphraseencryption
gpg --armor --comment "$comment" --no-options --output
passphraseencryption.gpg --symmetric passphraseencryption
shred -u passphraseencryption ; clear
echo "Outputting passphrase encrypted message"; echo "" ; echo "" ;
cat passphraseencryption.gpg ; echo "" ; echo "" ;
shred -u passphraseencryption.gpg ;
read -p "Hit enter to exit" temp; clear
}

keys ()
{
# Opens up kgpg keymanager
kgpg -k
}

encryptfile ()
{
zenity --title="zcrypt: Select a file to encrypt" --file-selection > zcrypt
encryptthisfile=`cat zcrypt`;rm zcrypt
# Use ascii armor
#  --no-options (for NO gui usage)
gpg -acq --yes ${encryptthisfile}
zenity --info --title "File Encrypted" --text "$encryptthisfile has been
encrypted"
}

decryptfile ()
{
zenity --title="zcrypt: Select a file to decrypt" --file-selection > zcrypt
decryptthisfile=`cat zcrypt`;rm zcrypt
# NOTE: This will OVERWRITE existing files with the same name !!!
gpg --yes -q ${decryptthisfile}
zenity --info --title "File Decrypted" --text "$encryptthisfile has been
decrypted"
}

################### End gpg functions ##################

[Jun 11, 2007] Life After Coffee " Customize your bash prompt

  1. I stumbled upon this site and thought I could give Gary's promt a try. I like it a lot and modified it a bit for use with colorful terminals. Here's what I use now:


    PS1="\[33[01;32m\]\u@\h \[33[01;31m\]uid:\${UID} \[33[01;34m\]\d \[33[01;33m\]\w
    \[33[00m\]\t \[33[01;32m\]>\[33[00m\] "

    The uid display is arguable I guess and I use it only on the root prompt.

    Cheers !

[Dec 22, 2006] Robert Body - escape codes for ksh in -etc-profile ... was Re mkpasswd, mkgroup - ini

22 Nov 2005 (cygwin.com) First, let me say... Cygwin is awesome, and the mailing lists are awesome.
It looks like a lot of work has been done to make it match a real unix.
:-)
**************************

Brian, another great help, thank you, especially for thelink:
--- http://cygwin.com/faq/faq.setup.html#faq.setup.home
HOME is determined as follows in order of decreasing priority:
1. HOME from the Windows environment, translated to POSIX form.
2. The entry in /etc/passwd
3. HOMEDRIVE and HOMEPATH from the Windows environment
4. /
---------
so, %HOME% variable set in Windows takes priority over  /etc/passwd
That has puzzled me for a few days because all the unix people say
"yup, change the user entry in /etc/passwd and that's your new home"

#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#
Actually, yes I can make my own group in cygwin :-)
(just needs a little unix stuff)
i called it "local" and set the group number of 10546 arbitrarily (a number not already used... and this is regular unix way of doing it)
--------------------
cat /etc/group
...
local:S-1-5-32-545:10546:robert.body
--------------------


and then in /etc/passwd, the 4th field I set to my newly created "local" group
--------------------
cat /etc/group
...
robert.body:unused_by_nt/2000/xp:13550:10546:
robert.body,U-DEN\robert.body,S-1-5-21-1659004503-484061587-839522115-3550:
/cygdrive/c/home/Owner:/bin/bash
--------------------

and then ... ta-daaaa ... my own group of "local" 

/cygdrive/c/cygwin/home/Owner> touch 1; ls -alp 1
-rw-r--r--  1 robert.body local 0 Nov 22 12:17 1
/cygdrive/c/cygwin/home/Owner>
#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--#--

I don't suppose there is a way of NOT letting %HOME% take priority over "/etc/passwd" for my home directory?

Brian,since you know about so many things, how come the following ksh doesn't work in
1) Linux xyz 2.4.7-10 #1 Thu Sep 6 17:27:27 EDT 2001 i686 unknown
2) HP-UX xyz B.11.00 U 9000/785 2004606272 unlimited-user license

the PS1 line below puts path into the title of the xterm, and puts "$PWD" into prompt
and this works fine in bash (different section of /etc/profile), but not in ksh 

---------taken from cygwin's /etc/profile--------------------
...
ksh*     | -ksh*     | */ksh* | \
ksh*.exe | -ksh*.exe | */ksh*.exe )
       # Set a HOSTNAME variable
       typeset -l HOSTNAME

# Set a default prompt of: user@host and current_directory
PS1='^[]0;${PWD}^G
^[[32m${USER}@${HOSTNAME} ^[[33m${PWD}^[[0m
$ '
-------------------------------------------------------------
Basically the escape codes are being ignored in ksh, but it came from cygwin's /etc/profile so it must be perfect right?
(i set USER=me and HOSTNAME=myserver
(I execute t2, copied cygwin file with the above): 

1) cygwin-----------------running pdksh from today's setup.exe-------
$echo $0
ksh
$. /etc/profile
^[]0;/cygdrive/u^G
^[[32mrobert.body@dpc6528 ^[[33m/cygdrive/u^[[0m
$

2) linux-----------------------------------
$. t2
^[]0;/tmp^G
^[[32mme@myserver ^[[33m/tmp^[[0m
$

3) hp-----------------------------------
$. t2
^[]0;/OnSight/opscntl^G
^[[32mme@myserver ^[[33m/OnSight/opscntl^[[0m
$
-----------------------------------------

-Robert

[Dec 22, 2006]UNIX projects

The PS1 prompt

If you want to have the prompt above with user@nameserver:directory I can recommend these settings for Korn shell 

UID=`id -u`
case $UID in
0) PS1S='# ';;
esac
PS1S=${PS1S:-'$ '}
HOSTNAME=${HOSTNAME:-`uname -n`}
HOST=${HOSTNAME%%.*}
# Set prompt
PS1='$USER@$HOST:${PWD##*/}$PS1S'
This will make your root prompt be a # and other users have $, while having the hostname without the domain name and only the last part of the working directory is shown.

[Dec 22, 2006] Learn Unix - A sample .profile for Korn shell users

#-----------------------------------------------#
# A sample .profile file for Korn shell users #
#-----------------------------------------------#
# Courtesy of Developer's Daily #
# http://www.DevDaily.com #
#-----------------------------------------------#

PATH=$PATH:/usr/local/bin:/usr/gnu/bin:.

set -o vi # enable the ability to recall previous commands with

PS1='$PWD> ' # set the prompt to display the current directory

#----------------------------#
# a few Korn shell aliases #
#----------------------------#

alias lc="ls -C"
alias lm="ls -al | more"
alias dirs="ls -al | grep '^d'" # show the dir's in the current dir
alias h=history # show the history of commands issued

alias nu="who|wc -l" # nu - number of users
alias np="ps -ef|wc -l" # np - number of processes running
alias p="ps -ef"

# mimick a few DOS commands with these aliases:

alias cd..="cd ../.."
alias cd...="cd ../../.."
alias dir="ls -al"
alias edit=vi
alias help=man
alias path="echo $PATH"

[Dec 20, 2006] The UNIX Forums - Edit .profile

RTM 06-11-2002, 11:32 AM

Here is a good example from ksh .profile for Solaris

################################################################################
# Name: .profile
# Description: This is root's profile. Login shells source this after
# /etc/profile. It is used to define root's environment.
# All non-environment configuration will be done in the
# shell specific resource file.
# Special: ENV= is specific to ksh to indicate the name of it's
# resource file. Bourne shell ignores this.
# Author: Ryan T. Tennant
# Version: 0.1
# Date: 2000/08/09
#
################################################################################

default_paths() {
PATH="/usr/bin:/usr/sbin:/sbin:/usr/local/bin"
MANPATH="/usr/man:/usr/local/man"
LD_LIBRARY_PATH="/usr/lib:/usr/local/lib"
OS="`/usr/bin/uname -s | /usr/bin/grep -ci sun`"
}

check_openwindows() {
if [ -d /usr/openwin ]; then
PATH="$PATH:/usr/openwin/bin:/usr/dt/bin"
MANPATH="$MANPATH:/usr/openwin/man:/usr/dt/man"
LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/usr/openwin/lib:/usr/dt/lib"
fi
}

check_build_environment() {
if [ -d /usr/ccs ]; then
PATH="$PATH:/usr/ccs/bin"
LD_LIBRARY_PATH="$LD_LIBRARY_PATH:/usr/ccs/lib"
fi
}

check_online_disk_suite() {
if [ -d /usr/opt/SUNWmd ]; then
PATH="$PATH:/usr/opt/SUNWmd/sbin"
MANPATH="$MANPATH:/usr/opt/SUNWmd/man"
fi
}

check_veritas_volume_manager() {
# Version 2.x
if [ -x /opt/VRTSvxva/bin/vxva ]; then
PATH="$PATH:/opt/VRTSvxva/bin"
MANPATH="$MANPATH:/opt/VRTSvxva/man"
fi

# Version 3.x
if [ -x /opt/VRTSvmsa/bin/vmsa ]; then
PATH="$PATH:/opt/VRTSvmsa/bin"
MANPATH="$MANPATH:/opt/VRTSvxvm/man:/opt/VRTSvmsa/man"
fi
}

check_sun_ent_volume_manager() {
if [ -d /opt/SUNWvxva ]; then
PATH="$PATH:/opt/SUNWvxva/bin"
MANPATH="$MANPATH:/opt/SUNWvxvm/man:/opt/SUNWvxva/man"
fi
}

check_naviscore() {
if [ -d /opt/CascadeView ]; then
. /opt/CascadeView/etc/cvdb.cfg
. /opt/CascadeView/etc/cascadeview.cfg
. /opt/sybase/.sybenv

PATH="$PATH:/opt/OV/bin"
XUSERFILESEARCHPATH="/opt/CascadeView/app-defaults/%N:$XUSERFILESEARCHPATH"

export XUSERFILESEARCHPATH
fi
}

check_networker() {
if [ -d /usr/bin/nsr ]; then
PATH="$PATH:/usr/bin/nsr:/usr/sbin/nsr"
fi
}

check_cluster() {
if [ -d /opt/SUNWcluster ]; then
PATH="$PATH:/opt/SUNWcluster/bin"
MANPATH="$MANPATH:/opt/SUNWcluster/man"
fi
}

generate_paths() {
default_paths
check_openwindows
check_build_environment
check_online_disk_suite
check_veritas_volume_manager
check_sun_ent_volume_manager
check_naviscore
check_networker
check_cluster
}

set_options() {
case "$1" in
*ksh)
EDITOR="vi"
ENV=".kshrc"
HOSTNAME=`/usr/bin/uname -n | /usr/bin/cut -d. -f1`
PAGER="/usr/bin/more"
if [ $OS -gt 0 ]; then
USER=`/usr/xpg4/bin/id -un`
else
USER=`id -un`
fi
;;
*sh)
EDITOR="vi"
HOSTNAME=`/usr/bin/uname -n | /usr/bin/cut -d. -f1`
PAGER="/usr/bin/more"
cd() {
chdir $*
set_prompt `basename $0`
}
if [ $OS -gt 0 ]; then
USER=`/usr/xpg4/bin/id -un`
else
USER=`id -un`
fi
;;
esac
}

set_prompt() {
case "$1" in
-ksh)
PS1='[$USER@$HOSTNAME]:$PWD
# '
;;
-sh)
PWD=`pwd`
PS1="[$USER@$HOSTNAME]:$PWD
# "
;;
esac
}

export_environment() {
export ENV PAGER HOSTNAME LD_LIBRARY_PATH MANPATH PAGER PATH PS1
}

# begin environment

generate_paths
set_options "$0"
set_prompt "$0"
export_environment

# proceed to $ENV for ksh resources

Keep Ryan's name in it - he did write it afterall.

[Feb 1, 2006] Sys Admin v15, i02 Implementing Standard Login Scripts by John Spurgeon and Ed Schaefer

Consider a server model where numerous Unix servers are distributed across numerous production sites hosting database engines and other software applications. Also, assume that only the local systems administrators have command-line access. We think standardizing the administrator's login scripts is a good way to maintain high application availability.

We could implement standard login scripts via skeleton directories. In the Solaris environment, the useradd command provides the -k option, which specifies a skeleton directory. Files from a skeleton directory, such as .profile, are copied into users' home directories when new accounts are created.

There are two reasons we shy away from using skeleton directories to standardize login scripts. First, it can be difficult to make changes to scripts once users have been added. Not only do files in the skeleton directories have to be modified, but all of the existing users' scripts have to be updated, too. Second, we did not want to give users access to the logic responsible for setting up the majority of their environment, and we thought that preventing users from modifying $HOME/.profile was too restrictive.

Instead, we placed the necessary environment setup commands in two special files: /etc/profile and /etc/.kshrc. When a user logs in, the program called "login" spawns a shell -- typically the Korn shell on our servers. The Korn shell looks for login scripts /etc/profile and $HOME/.profile and executes them if they exist. The Korn shell also looks for the file referenced by the environment variable ENV (set to /etc/.kshrc on our servers) and executes it if it exists; this happens whenever the Korn shell is invoked -- not just at login time.

Listing 1 shows what /etc/profile looks like on all of our servers. 

# /etc/profile

. /opt/logins/bin/disable_interrupts

umask 022
ulimit -n 1024
. /etc/setenv_path
. /etc/setenv_true_false

if [ `tty` = /dev/console ]
then
   TERM=AT386
   export TERM
fi

case $LOGNAME in
keysync | pwadmin | entry | ontape-c)
    ;;
*)
    . /etc/setenv_informix
    . /etc/setenv_ifics
    readonly ENVFILE=/etc/.kshrc
    readonly ENV='${ENVFILE[(_$-=1)+(_=0)-(_$-!=_${-%%*i*})]}'
    export ENVFILE ENV
    ;;
esac

. /opt/logins/bin/enable_interrupts
# end Listing 1

Note the use of the "dot" command to source files, such as /etc/setenv_path. Modularizing our login scripts this way keeps them short and easy to read. Another feature of our login scripts is the use of the readonly function to protect the value of certain variables, such as ENV.

The most interesting thing about /etc/profile is the way ENV is set: 

readonly ENV='${ENVFILE[(_$-=1)+(_=0)-(_$-!=_${-%%*i*})]}'

This code evaluates to a two-position array: ENVFILE[0]=/etc/.kshrc and ENVFILE[1] is null. When a shell is interactive, ENVFILE[0] executes, thus setting the commands in /etc/.kshrc. Obviously, a non-interactive shell does nothing since ENVFILE[1] is null. For a more detailed explanation, see: 

http://docs.hp.com/en/B2355-90046/ch23s02.html

Recall that the file referenced by $ENV is executed every time a new shell spawns. This can lead to inefficiencies if a file like /etc/.kshrc contains commands that only need to be executed at login time. This complicated way of setting ENV prevents /etc/.kshrc from being read when the shell is not in interactive mode.

Listing 2 is our /etc/.kshrc file. Like /etc/profile, it is also a short script due to the use of several dot commands. 

# /etc/.kshrc

if [[ -o interactive ]]
then
    . /opt/logins/bin/disable_interrupts

    . /etc/setenv_path
    . /etc/setenv_true_false
    . /etc/setenv_informix
    . /etc/setenv_ifics
    . /etc/setenv_user

    . /opt/logins/bin/sh_history.initialize
    . /opt/logins/bin/login_alert
    /opt/logins/bin/greeting
    trap "/etc/.logout" 0

    . /opt/logins/bin/enable_interrupts
fi

# end Listing 2

The script begins with the following if statement: 

if [[ -o interactive ]]

This is a simple way to test for an interactive shell. The if statement probably isn't necessary, because it has essentially the same effect as setting ENV the way we did. If you're bothered by inefficiencies, choose one technique or the other. If you're paranoid that something could go wrong with the ENV approach, you may want to use both.

We don't include full listings of all the dot scripts shown in /etc/profile and /etc/.kshrc, since many of them are peculiar to our environment. However, a few are worth sharing.

Listing 3, /opt/logins/bin/disable_interrupts, 

# /opt/logins/bin/disable_interrupts
trap "exit 1" 1 2 3 9 15 16 17

if [[ -o interactive ]]
then
    stty -isig
    stty intr ''
    stty quit  ''
    stty erase '^H'
    stty kill ''
    stty eof ''
    stty eol ''
    stty eol2 ''
    stty swtch ''
    stty start ''
    stty stop ''
    stty susp ''
    stty dsusp ''
    stty rprnt ''
    stty flush ''
    stty werase ''
    stty lnext ''
fi
# end Listing 3

and Listing 4, /opt/logins/bin/enable_interrupts, 

# /opt/logins/bin/enable_interrupts

stty sane
stty istrip
stty erase '^h'
stty quit '^\'
stty susp '^z'
stty intr '^c'

trap 1 2 3 9 15 16 17
# end Listing 4

are two scripts we use to manipulate the environment during the login process to prevent users from interrupting the login scripts and gaining premature access to a command line.

Listing 5 is a file we created named setenv_user. 

# /etc/setenv_user

REAL_USER=`/usr/xpg4/bin/id -urn`
EFFECTIVE_USER=`/usr/xpg4/bin/id -un`
TERM_USER=`/usr/bin/who -m | /usr/bin/cut -d' ' -f1`
export REAL_USER EFFECTIVE_USER TERM_USER

TERM=${TERM:=AT386}
MAIL=/usr/mail/${REAL_USER:-anonymous}
PAGER=/usr/local/bin/less
LESS="-P-Less- %pb\%"
LESSSECURE=1
EDITOR=/usr/bin/vi
VISUAL=/usr/bin/vi
EXINIT="set showmode tabstop=4"

if [ "$REAL_USER" != "$TERM_USER" ]
then
        PS1=${REAL_USER:-anonymous}"("${TERM_USER:-anonymous}")"@`uname -n`':${PWD} % '
else
        PS1=${REAL_USER:-anonymous}@`uname -n`':${PWD} % '
fi

PS2='% '
PS4='$0 line ${LINENO}: '
WWW_HOME=/opt/docs/html/index.html
export TERM MAIL PAGER LESS LESSSECURE EDITOR VISUAL EXINIT \
  PS1 PS2 PS4 WWW_HOME

alias pd=pushd
alias help=lynx

# end /etc/setenv_user

In setenv_user, we set and export some custom environment variables, such as REAL_USER and EFFECTIVE_USER, as well as several common variables, such as TERM, MAIL, PAGER, LESS, PS1, and PS2.

Finally, note the following command in /etc/.kshrc: 

trap "/etc/.logout" 0

This trap statement causes the shell to execute the command /etc/.logout when the shell exists.

Login scripts need to be tailored to the requirements of your environment and the preferences of your users. The approach we've taken to managing our login scripts won't work for everyone. But, hopefully, we've presented a few useful techniques -- some of which you might want to adopt.

Our next column builds upon our custom login idea. We present a method for archiving individual user's history files by manipulating shell variable HISTFILE.

References

Hewlett Packard. 1992. SHELLS: User's Guide, HP 9000 Computers. Palo Alto, CA. -- http://docs.hp.com/en/B2355-90046/ch23s02.html

[Feb 19, 2001] A brief introduction to the bash shell -- contains two sample bash dot files for C shell users

A sample annotated ~/.bash_profile

This file is executed when you first login, the variables are all exported so that they are available to all subshells.

This has a bit of tricky programming in it where all of the paths are stored in separate files - so that they can be easily changed without modifying the original ~/.bash_profile file.

# ~/.bash_profile
# Executed by login shells

# Converts a \n separated list into a colon separated list
colonise() {
        /bin/cat $1 | /bin/tr "\012" ":"
}

### Variables used by bash itself

# Paths...
# these all use the above "colonise" function to
# convert a list of paths on separate lines into
# a colon separated list.
export PATH=`colonise ~/.path`
export MANPATH=`colonise ~/.manpath`
export MAILPATH=`colonise ~/.mailpath`
export CDPATH=`colonise ~/.cdpath`

# Control history
# I don't like to have a lot of 
# old commands hanging around.
export HISTFILESIZE=100
export HISTSIZE=10
export HISTCONTROL=ignoreboth

# Control file name completion: ignore the following suffixes
export FIGNORE=`colonise ~/.fignore`

# Exiting bash deliberately and involuntarily
# export IGNOREEOF=1
export TMOUT=3600

# Prompt
export PS1="\u@\h \W [\!]\$: "

### Variables that don't relate to bash

# Set variables for a warm fuzzy environment
export CVSROOT=~/.cvsroot
export PGPPATH=~/.pgp
export EDITOR=/usr/local/bin/emacs
export PAGER=/usr/local/bin/less
export PRINTER=134

# Execute the subshell script
source ~/.bashrc

# end of ~/.bash_profile

A sample ~/.bashrc which is executed each time a shell or subshell is started. It just contains aliases, some functions and a couple of miscellaneous settings. 

# ~/.bashrc 
# executed by login and subshells

# aliases

# search man pages by subject
alias a='man -k'

# edit and re-read this file
alias be='$EDITOR ~/.bashrc ; source ~/.bashrc'

# add the current directory to the "cdpath"
alias cdpath='pwd >> ~/.cdpath ; export CDPATH=`colonise ~/.cdpath`'

# abbreviations for some common commands
alias f=finger
alias h=history
alias j=jobs
alias l='ls -lF'
alias la='ls -alF'
alias lo=logout
alias ls='ls -F'
alias m='less -a -i -P='

# functions

# A new version of "cd" which
# prints the directory after cd'ing
cd() {
        builtin cd $1
        pwd
}
# add the directoried specified to the path file and re-read it.
pathadd() {
        for p in $*
        do
                echo $p >> ~/.path
        done
        export PATH=`colonise ~/.path`
}


# Other settings
umask 027
mesg y

# end of ~/.bashrc 
# Uncomment the following if you prefer vi style command editing 
# to emacs style

# set +o emacs
# set -o vi

# Important startup procedures...
/usr/local/games/bin/fortune
echo

# end of ~/.bashrc

You can also create a ~/.bash_logout file that is executed whenever you log out.

[Jan 14, 2000] Dot files by Juhapekka Tolvanen <[email protected]> Thanks Juhapekka


[May 16, 1999] script.hints

[ May 16, 1999] Startup FAQ for Csh & Tcsh

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Controlling the prompt in bash

The value of the variable $PROMPT_COMMAND is examined just before Bash prints each primary prompt. If it is set and non-null, then the value is executed just as if you had typed it on the command line. In addition, the following table describes the special characters which can appear in the PS1 variable:

\t
the time, in HH:MM:SS format.
\d
the date, in "Weekday Month Date" format (e.g. "Tue May 26").
\n
newline.
\s
the name of the shell, the basename of $0 (the portion following the final slash).
\w
the current working directory.
\W
the basename of $PWD.
\u
your username.
\h
the hostname.
\#
the command number of this command.
\!
the history number of this command.
\nnn
the character corresponding to the octal number nnn.
\$
if the effective uid is 0, #, otherwise $.
\\
a backslash.
\[
begin a sequence of non-printing characters. This could be used to embed a terminal control sequence into the prompt.
\]
end a sequence of non-printing characters.

Etc

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