Bash Debugger

Bashdb is nice debugger for bash, but usually it is not installed by default. You either need to install it from source using version 3 if you have bash 3 and version 4 if you have bash 4.1 or bash 4.2. See BASH with Debugger and Improved Debug Support and Error Handling or to the link to the tarball. Installation consist of three commands

cd bashdb-3.x... # <-- put name of release for 3.x...
./configure      # use --with-bash-src to speed up bash debugging
make && make check 
su -c 'make install' # should run as root

bash -L ./bashdb script-to-be-debugged options-to-debugged-program

If bashdb has been installed you don’t need to use option “-L .” Instead you would type simply

 bashdb script-to-be-debugged options-to-debugged-program

I would recommend to check syntax of the bash script before using the debugger using option "-n", for example 

bash -n your_script.sh

Let's summarize the essentials of the debugger invocation:

• type bash --debugger script-name  or bashdb script-name to start the BASH debugger. 
• type bashdb -c command string to run a command or one-liner under the debugger.
• Or type bashdb -h  to get help about options available (bashdb --help   works too)

Two useful commands are n (next) - next step and p (print) -- print the variable or expression. Type quit or C-d inside the debugger to exit. Other way to terminate the debugger is to use the kill command. kill -9 can be used in cases where quit doesn't work.

bashdb<0> help
Available commands:
  /          debug    enable   help     next     show    step-      untrace
  alias      delete   eval     history  print    signal  tbreak     up     
  break      disable  examine  info     pwd      skip    trace      watch  
  commands   display  file     kill     quit     source  tty        where  
  condition  down     frame    list     restart  step    unalias  
  continue   edit     handle   load     set      step+   undisplay

Basdb documentation has several examples on how to use bashdb. See  Summary of the BASH Debugger

Dynamic activation from scripts

You can activate the debugger within the script. you can make an explicit call to the debugger in your script

_Dbg_debugger 

Here is an example:

  for ((i=1; i<=10; i++)) ; 
        (( 5 == i )) && { _Dbg_debugger }
        date=$(date)
        echo "$date"
        sleep 2
  done 

You can also turn on and off line tracing with _Dbg_linetrace_on

Frontends

There are also two front-ends available as well. One can also enter the debugger inside emacs via the command M-x bashdb after loading Emacs' Grand Unified Debugger, gud. See Using the BASH debugger from GNU Emacs. And there is support in a DDD for bash.

Getting the bashdb

bashdb is available as a source package in Debian, Fedora and OpenSuse. The Ubuntu repository contains a package for bashdb too.

Please note that for bash 4.x you need   version of bashdb, version 4.0.x, while for bash 3.x. version of bashdb should be 3.0.x.

Tarball with debugger is downloadable from Sourceforge:

https://sourceforge.net/project/showfiles.php?group_id=61395

Recommended Links

Softpanorama Recommended

Top articles

Sites

• BASH with Debugger and Improved Debug Support and Error Handling
• BASH Debugger  -- Getting started
• BASH Debugger Debugging with the BASH debugger
• rpmseek.com - The search engine for Linux rpm and Debian packages
• bashdb-4.0_0.4-1.pm.2.1.x86_64.rpm - openSUSE 11.3 - Download & Review
• bashdb-4.0_0.4-2.fc13.noarch RPM

Reference

• Options
  • -h | --help
  • This option causes the BASH debugger to print some basic help and exit.
  • -V | --version
  • This option causes the BASH debugger to print its version number, no-warranty blurb, and exit.
  • -A | --annotate level
  • Add additional output which allows front-ends to track what's going on without having to poll for such vital information. The default annotation level is 0 (none). If you are running inside GNU Emacs using the Emacs code from this package, an annotation level 3 when set will allow for automatic tracking of frames and breakpoints. See section Annotation Level (‘set annotate’).
  • -c | --command cmd
  • Run the string instead of running a script
  • -B | --basename
  • This option causes the BASH debugger to print its version number and no-warranty blurb, and exit.
  • -n | --nx | --no-init
  • Do not execute commands found in any initialization files. Normally, BASH executes the commands in these files after all the command options and arguments have been processed. See section Command files.
  • -q | --quiet
  • “Quiet”. Do not print the introductory and copyright messages. These messages are also suppressed in batch mode.
  • -t | --terminal | --tty tty
  • “Terminal output”. Set the file or terminal that you want debugger command output to go to. Note that the debugger output is independent of the debugged script output.
  • -x | --eval-command
  • execute debugger commands from cmdfile.
  • -L | --library directory
  • Set directory where debugger files reside to directory. The default location is ../lib/bashdb relative to the place that the bashdb script is located. For example if bashdb is located in /usr/local/bin/bashdb, the default library location will be /usr/local/lib/bashdb which may or may not exist. If it doesn't you'll get an error when you run bashdb. Only if the default location is incorrect, should you need to use the -L option.
  • -T | --tempdir directory
  • Set directory to use for writing temporary files.

Etc

Society

Groupthink : Two Party System as Polyarchy : Corruption of Regulators : Bureaucracies : Understanding Micromanagers and Control Freaks : Toxic Managers :   Harvard Mafia : Diplomatic Communication : Surviving a Bad Performance Review : Insufficient Retirement Funds as Immanent Problem of Neoliberal Regime : PseudoScience : Who Rules America : Neoliberalism  : The Iron Law of Oligarchy : Libertarian Philosophy

Quotes

War and Peace : Skeptical Finance : John Kenneth Galbraith :Talleyrand : Oscar Wilde : Otto Von Bismarck : Keynes : George Carlin : Skeptics : Propaganda  : SE quotes : Language Design and Programming Quotes : Random IT-related quotes :  Somerset Maugham : Marcus Aurelius : Kurt Vonnegut : Eric Hoffer : Winston Churchill : Napoleon Bonaparte : Ambrose Bierce :  Bernard Shaw : Mark Twain Quotes

Bulletin:

Vol 25, No.12 (December, 2013) Rational Fools vs. Efficient Crooks The efficient markets hypothesis : Political Skeptic Bulletin, 2013 : Unemployment Bulletin, 2010 :  Vol 23, No.10 (October, 2011) An observation about corporate security departments : Slightly Skeptical Euromaydan Chronicles, June 2014 : Greenspan legacy bulletin, 2008 : Vol 25, No.10 (October, 2013) Cryptolocker Trojan (Win32/Crilock.A) : Vol 25, No.08 (August, 2013) Cloud providers as intelligence collection hubs : Financial Humor Bulletin, 2010 : Inequality Bulletin, 2009 : Financial Humor Bulletin, 2008 : Copyleft Problems Bulletin, 2004 : Financial Humor Bulletin, 2011 : Energy Bulletin, 2010 : Malware Protection Bulletin, 2010 : Vol 26, No.1 (January, 2013) Object-Oriented Cult : Political Skeptic Bulletin, 2011 : Vol 23, No.11 (November, 2011) Softpanorama classification of sysadmin horror stories : Vol 25, No.05 (May, 2013) Corporate bullshit as a communication method  : Vol 25, No.06 (June, 2013) A Note on the Relationship of Brooks Law and Conway Law

History:

Fifty glorious years (1950-2000): the triumph of the US computer engineering : Donald Knuth : TAoCP and its Influence of Computer Science : Richard Stallman : Linus Torvalds  : Larry Wall  : John K. Ousterhout : CTSS : Multix OS Unix History : Unix shell history : VI editor : History of pipes concept : Solaris : MS DOS :  Programming Languages History : PL/1 : Simula 67 : C : History of GCC development :  Scripting Languages : Perl history   : OS History : Mail : DNS : SSH : CPU Instruction Sets : SPARC systems 1987-2006 : Norton Commander : Norton Utilities : Norton Ghost : Frontpage history : Malware Defense History : GNU Screen : OSS early history

Classic books:

The Peter Principle : Parkinson Law : 1984 : The Mythical Man-Month :  How to Solve It by George Polya : The Art of Computer Programming : The Elements of Programming Style : The Unix Hater’s Handbook : The Jargon file : The True Believer : Programming Pearls : The Good Soldier Svejk : The Power Elite

Most popular humor pages:

Manifest of the Softpanorama IT Slacker Society : Ten Commandments of the IT Slackers Society : Computer Humor Collection : BSD Logo Story : The Cuckoo's Egg : IT Slang : C++ Humor : ARE YOU A BBS ADDICT? : The Perl Purity Test : Object oriented programmers of all nations : Financial Humor : Financial Humor Bulletin, 2008 : Financial Humor Bulletin, 2010 : The Most Comprehensive Collection of Editor-related Humor : Programming Language Humor : Goldman Sachs related humor : Greenspan humor : C Humor : Scripting Humor : Real Programmers Humor : Web Humor : GPL-related Humor : OFM Humor : Politically Incorrect Humor : IDS Humor : "Linux Sucks" Humor : Russian Musical Humor : Best Russian Programmer Humor : Microsoft plans to buy Catholic Church : Richard Stallman Related Humor : Admin Humor : Perl-related Humor : Linus Torvalds Related humor : PseudoScience Related Humor : Networking Humor : Shell Humor : Financial Humor Bulletin, 2011 : Financial Humor Bulletin, 2012 : Financial Humor Bulletin, 2013 : Java Humor : Software Engineering Humor : Sun Solaris Related Humor : Education Humor : IBM Humor : Assembler-related Humor : VIM Humor : Computer Viruses Humor : Bright tomorrow is rescheduled to a day after tomorrow : Classic Computer Humor

The Last but not Least Technology is dominated by two types of people: those who understand what they do not manage and those who manage what they do not understand ~Archibald Putt. Ph.D

The statements, views and opinions presented on this web page are those of the author (or referenced source) and are not endorsed by, nor do they necessarily reflect, the opinions of the Softpanorama society. We do not warrant the correctness of the information provided or its fitness for any purpose. The site uses AdSense so you need to be aware of Google privacy policy. You you do not want to be tracked by Google please disable Javascript for this site. This site is perfectly usable without Javascript.

Last modified: July 13, 2017