Commands tagged logging (15)

  • Don't spam root. Log your cronjob output to syslog

    This command will log the output of your simple cronjobs to syslog, and syslog will take it from there. Works great for monitoring scripts which only produce simple output. Advantages: * This can be used by regular users, without modifying system files like /etc/syslog.conf * Reduce cron spam to root@localhost (Please stop spaming the sysadmins) * Uses common tools like syslog (and logrotate) so that you don't need to maintain yet another krufty logfile. * Still ensures that the output is logged somewhere, for posterity. Perhaps it's stored the secure, central syslog server, for example. * Seems to work fine on Ubuntu, CentOS, FreeBSD & MacOSX Show Sample Output


    6
    */5 * * * * root /usr/local/nagios/sbin/nsca_check_disk 2>&1 |/usr/bin/logger -t nsca_check_disk
    StefanLasiewski · 2010-07-02 00:47:05 8
  • Debug SSH at the Maximum Verbosity Level

    When debugging an ssh connection either to optimize your settings ie compression, ciphers, or more commonly for debugging an issue connecting, this alias comes in real handy as it's not easy to remember the '-o LogLevel=DEBUG3' argument, which adds a boost of debugging info not available with -vvv alone. Especially useful are the FD info, and the setup negotiation to create a cleaner, faster connection. Show Sample Output


    4
    alias sshv='ssh -vvv -o LogLevel=DEBUG3'
    AskApache · 2010-10-30 11:23:52 5
  • View all new log messages in real time with color

    This will show all changes in all log files under /var/log/ that are regular files and don't end with `gz` nor with a number Show Sample Output


    4
    find /var/log -type f -iregex '.*[^\.][^0-9]+$' -not -iregex '.*gz$' 2> /dev/null | xargs tail -n0 -f | ccze -A
    rubo77 · 2014-07-29 17:11:17 6
  • Monitor a file with tail with timestamps added


    3
    tail -f file |xargs -IX printf "$(date -u)\t%s\n" X
    unefunge · 2010-11-25 11:23:13 6
  • Automatic ssh Session Logger

    A wrapper around ssh to automatically provide logging and session handling. This function runs ssh, which runs screen, which runs script. . The logs and the screen session are stored on the server. This means you can leave a session running and re-attach to it later, or from another machine. . . Requirements: * Log sessions on a remote server * Transparent - nothing extra to type * No installation - nothing to copy to the server beforehand . Features: * Function wrapper delegating to ssh - so nothing to remember - uses .ssh/config as expected - passes your command line option to ssh * Self-contained: no scripts to install on the server * Uses screen(1), so is: - detachable - re-attachable - shareable * Records session using script(1) * Configurable log file location, which may contain variables or whitespace L="$HOME" # local variable L="\$HOME" # server variable L="some space" . Limitations: * Log dir/file may not contain '~' (which would require eval on the server) . . The sessions are named by the local user connecting to the server. Therefore if you detach and re-run the same command you will reconnect to your original session. If you want to connect/share another's session simply run: USER=bob ssh root@server . The command above is stripped down to an absolute minimum. A fully expanded and annotated version is available as a Gist (git pastebin): https://gist.github.com/flatcap/3c42326abeb1197ee714 . If you want to add timing info to script, change the command to: ssh(){ L="\$HOME/logs/$(date +%F_%H:%M)-$USER";/usr/bin/ssh -t "$@" "mkdir -p \"${L%/*}\";screen -xRRS $USER script --timing=\"$L-timing\" -f \"$L\"";} Show Sample Output


    3
    ssh(){ L="\$HOME/logs/$(date +%F_%H:%M)-$USER";/usr/bin/ssh -t "$@" "mkdir -p \"${L%/*}\";screen -xRRS $USER script -f \"$L\"";}
    flatcap · 2015-10-14 13:14:29 11
  • Read Python logs with tracebacks in color


    1
    pygmentize -l pytb myapp.log | less -SR
    manuq · 2013-01-10 03:13:41 5
  • creating you're logging function for your script

    You could also pipe to logger.


    1
    logger -t MyProgramName "Whatever you're logging"
    pdxdoughnut · 2013-10-22 16:34:49 7
  • Realtime lines per second in a log file, with history

    This is similar to standard `pv`, but it retains the rate history instead of only showing the current rate. This is useful for spotting changes. To do this, -f is used to force pv to output, and stderr is redirected to stdout so that `tr` can swap the carriage returns for new lines. (doesn't work correctly is in zsh for some reason. Tail's output isn't redirected to /dev/null like it is in bash. anyone know why? ???????) Show Sample Output


    1
    tail -f access.log | pv -l -i10 -r -f 2>&1 >/dev/null | tr /\\r \ \\n
    varenc · 2020-04-19 02:07:40 97
  • Analyze Apache Web Log Statistics starting on DATE x

    GoAccess is an open source real-time Apache web log analyzer and interactive viewer that runs in a terminal in *nix systems. It provides fast and valuable HTTP statistics for system administrators that require a visual server report on the fly. http://goaccess.prosoftcorp.com/ Show Sample Output


    0
    sed -n '/05\/Dec\/2010/,$ p' access.log | goaccess -s -b
    allinurl · 2010-12-13 17:37:33 4
  • creating you're logging function for your script

    Put this logging function in you're script, when need it call it. command || logme "Error with command"


    0
    logme(){ echo "$(date +%d-%m-%Y-%H:%M) => $0 @ $1 returned error" >> persoscript.log }
    qcjn · 2013-10-22 15:55:01 7
  • Monitor a log file, filling up all available space in the terminal window and preventing line wrap

    This bash one-liner will let you watch the tail end of a log file in real time.


    0
    watch -n 4 "tail -n $(expr $(tput lines) - 4) /var/log/apache2/access.log | cut -c 1-$(tput cols)"
    atw527 · 2013-12-03 23:45:25 10
  • Powershell Ping Logs Host Up/Down Events

    IMPORTANT: You need Windows PowerShell to run this command - in your Windows Command Prompt, type powershell Uses sajb to start a PowerShell background job that pings an IP host every 10 seconds. Any changes in the host's Up/Down state is time-stamped and logged to a file. Date/time stamps are logged in two formats: Unix and human-readable. A while(1) loop repeats the test every 10 seconds by using the sleep command. See the Sample Output for more detail. I use this command to log Up/Down events of my Motorola SB6141 cable modem (192.168.100.1). To end the logging, close the PowerShell window or use the "exit" command. Show Sample Output


    0
    sajb {$ip="192.168.100.1";$old=0;while(1){$up=test-connection -quiet -count 1 $ip;if($up-ne$old){$s=(date -u %s).split('.')[0]+' '+(date -f s).replace('T',' ')+' '+$ip+' '+$(if($up){'Up'}else{'Down'});echo $s|out-file -a $home\ping.txt;$old=$up}sleep 10}}
    omap7777 · 2015-12-28 20:33:08 15
  • Prepend text to stdout of running job

    Run a job in the background and prefix it's output with some string. This is particularly useful if you are running inside a docker container in a startup script (sue me, I'll run two jobs in a docker container if I want to) and you can run something like: /usr/sbin/nginx 2>&1 | awk '{print "[NGINX] " $0}' & /opt/jws-3.1/tomcat8/bin/catalina.sh run 2>&1 | awk '{print "[TOMCAT] " $0}' & while true; do ; done it can also be combined with tee to create a file log as well as a stdout log, for example if the script above where a script called "/bin/start-container.sh" then you could run /bin/start-container.sh | tee /var/log/containerlogs Show Sample Output


    0
    nginx 2>&1 | awk '{print "[NGINX] " $0}' &
    hvindin · 2017-04-25 22:18:38 20
  • tail all logs opened by all java processes

    Tail all logs that are opened by all java processes. This is helpful when you are on a new environment and you do not know where the logs are located. Instead of java you can put any process name. This command does work only for Linux. The list of all log files opened by java process: sudo ls -l $(eval echo "/proc/{$(echo $(pgrep java)|sed 's/ /,/')}/fd/")|grep log|sed 's/[^/]* //g'


    -1
    sudo ls -l $(eval echo "/proc/{$(echo $(pgrep java)|sed 's/ /,/')}/fd/")|grep log|sed 's/[^/]* //g'|xargs -r tail -f
    vutcovici · 2010-07-30 18:20:00 4
  • Polls fos network port usage


    -4
    while sleep 1; do date; (netstat -a -n | grep 80) ; done
    hute37 · 2011-05-16 07:56:56 6

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

Watch contents of a file grow
In this case, I'm keeping an eye on /var/log/messages, but of course any file will do. When I'm following a file, I generally don't want to see anything other than what has been added due to the command or service I've executed. This keeps everything clean and tidy for troubleshooting.

Get own public IP address
Returns your external IP address to the command line using only wget

Speed up builds and scripts, remove duplicate entries in $PATH. Users scripts are oftern bad: PATH=/apath:$PATH type of thing cause diplicate.
Thanks to the authors of: $ awk '!x[$0]++' and the author of: $ joinargs() { (local IFS="$1"; shift && echo "$*") } and others, we can have a fast Linux or android. IMPORTANT if you find a priority order problem in PATH you can push a path directory to the front without duplication as follows: $ PATH=/bin:$PATH then ... Check duplication with: $ echo $PATH|tr : '\n'|sort|uniq -d Finally do a very neat line by line list of $PATH: $ echo "${PATH//:/$'\n'} The speed up is very noticeable for android, and builds on Linux Ubantu are much faster with make and scripts. I will update the command on request. Timothy from SONY

OSX command to take badly formatted xml from the clipboard, cleans it up and puts it back into the clipboard.
This command can be used with xclip or xsel for use on a linux box.

Using vim to save and run your python script.
This will save and execute your python script every time your press the F5 function key. It can also be added to your .vimrc: autocmd BufRead *.py nmap :w^M:!python % NOTE: the ^M is not just caret-M, it can be created by type: ctrl-v ctrl-m

List files
Shortcut to list files in the current path.

Send your terminfo to another machine
I frequently use this trick to send my terminal settings to HPUX and older RHEL systems. This is due to the fact that terminfo support for rxvt-unicode (my preferred terminal app) does not exist on many older Linux and Unices.

Write comments to your history.
A null operation with the name 'comment', allowing comments to be written to HISTFILE. Prepending '#' to a command will *not* write the command to the history file, although it will be available for the current session, thus '#' is not useful for keeping track of comments past the current session.

append empty line after every line in file.txt

Prints a file leaving out all blank lines and comment-only lines
Does not print any line that either: - is empty - contains only spaces or tabs - starts with # - starts with spaces/tabs followed by a #

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for: