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Unix tail tail command is a standard way of watching log files in Unix. There is also less well known, but more useful utility called logtail. This is a Perl script which allows a system administrator to watch entries, as they are added, in any number of log files on one or more machines on a network. Logs which transfer to new files are automatically followed, and an option allows translation of numeric Internet addresses into the corresponding hostnames where possible. Log items can be relayed to one or more other hosts on the network, permitting a machine's local log files to be monitored there.
logtail [-t] -flogfile [-ooffsetfile]DESCRIPTION
logtail reads a specified file (usually a log file) and writes to the standard output that part of it which has not been read by previous runs of logtail. It prints the appropriate number of bytes from the end of logfile, assuming that all changes that are made to it are to add new characters to it.
logfile must be a plain file. A symlink is not allowed.
logtail stores the information about how much of it has already been read in a separate file called offsetfile. offsetfile can be omitted. If omitted, the file named logfile.offset in the same directory which contains logfile is used by default.
If offsetfile is not empty, the inode of logfile is checked. If the inode is changed, logtail simply prints the entire file. If the inode is not changed but logfile is shorter than it was at the last run of logtail, it writes a warning message to the standard output.
OPTIONS-f logfile to be read after offset
-o offsetfile stores offset of previous run
-t test mode - do not change offset in offsetfile
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This program will read in a standard text file and create an offset marker when it reads the end. The offset marker is read the next time logtail is run and the text file pointer is moved to the offset location. This allows logtail to read in the next lines of data following the marker. This is good for marking log files for automatic log file checkers to monitor system events.The package also provides logtail2, which better deals with rotated log files: If logtail2 finds that the inode of the file was changed, it assumes that the log has been rotated, and tries to find the file it was rotated to using heuristic plugins. If it finds the file, it will print the remainder of the file starting at the offset saved to the offset file. If a file with the correct inode was not found, logtail2 will only print the new file in its entirety before writing a new offset file.
Tags: System Administration: Logging, Implemented in: Perl, User Interface: Command Line, Role: Program, Scope: Utility, Purpose: Data Visualization, Works with: System Logs
inotail is a replacement for the 'tail' program found in the base installation of every Linux/Unix system. It makes use of the inotify infrastructure in recent versions of the Linux kernel to speed up tailing files in the follow mode (the '-f' option). Standard tail polls the file every second by default, while inotail listens to special events sent by the kernel through the inotify API to determine whether a file needs to be reread.
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
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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
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Last modified: March 12, 2019