Commands tagged log (39)

  • This will log your internet download speed. You can run gnuplot -persist <(echo "plot 'bps' with lines") to get a graph of it.

    echo $(date +%s) > start-time; URL=; while true; do echo $(curl -L --w %{speed_download} -o/dev/null -s $URL) >> bps; sleep 10; done &
    matthewbauer · 2009-09-19 21:26:06 2
  • Using the grep command, retrieve all lines from any log files in /var/log/ that have one of the problem states

    grep -2 -iIr "err\|warn\|fail\|crit" /var/log/*
    miketheman · 2009-06-17 19:41:04 3
  • Uses date to grep de logfile for today and uses it to get the last hour logs. Can be used to get last minute logs or today's logs. Show Sample Output

    grep -i "$(date +%b\ %d\ %H)" syslog
    rubenmoran · 2010-05-23 16:18:15 6
  • Returns logs between HH:M[Mx-My], for example, between 13:40 and 13:45. Show Sample Output

    grep -i "$(date +%b" "%d )13:4[0-5]" syslog
    rubenmoran · 2010-05-23 16:30:46 3
  • with discard wilcards in bash you can "tail" newer logs files to see what happen, any error, info, warn... Show Sample Output

    tail -f *[!.1][!.gz]
    piscue · 2009-03-06 16:24:44 4
  • This command finds the 5 (-n5) most frequently updated logs in /var/log, and then does a multifile tail follow of those log files. Alternately, you can do this to follow a specific list of log files: sudo tail -n0 -f /var/log/{messages,secure,cron,cups/error_log} Show Sample Output

    ls -drt /var/log/* | tail -n5 | xargs sudo tail -n0 -f
    kanaka · 2009-07-22 14:44:41 0
  • just change the date following the -r flag, and/or the user name in the user== conditional statement, and substitute yms_web with the name of your module

    svn log -v -r{2009-05-21}:HEAD | awk '/^r[0-9]+ / {user=$3} /yms_web/ {if (user=="george") {print $2}}' | sort | uniq
    jemptymethod · 2009-06-05 14:07:28 6

  • 4
    zcat access_log.*.gz | awk '{print $7}' | sort | uniq -c | sort -n | tail -n 20
    tkb · 2009-12-11 09:36:30 0
  • 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

    alias sshv='ssh -vvv -o LogLevel=DEBUG3'
    AskApache · 2010-10-30 11:23:52 0

  • 4
    nickoe · 2011-12-29 22:35:28 0
  • This one is tried and tested for Ubuntu 12.04. Works great for tailing any file over http.

    (echo -e "HTTP/1.1 200 Ok\n\r"; tail -f /var/log/syslog) | nc -l 1234
    adimania · 2013-02-09 06:15:42 0
  • This truncates any lines longer than 80 characters. Also useful for looking at different parts of the line, e.g. cut -b 50-100 shows columns 50 through 100.

    tail -f logfile.log | cut -b 1-80
    plasticboy · 2009-03-26 18:41:57 5

  • 3
    tail -f /var/log/squid/access.log | perl -p -e 's/^([0-9]*)/"[".localtime($1)."]"/e'
    godzillante · 2011-07-06 08:55:27 4
  • When you have one of those (log)files that only has epoch for time (since no one will ever look at them as a date) this is a way to get the human readable date/time and do further inspection. Mostly perl-fu :-/

    perl -F' ' -MDate::Format -pale 'substr($_, index($_, $F[1]), length($F[1]), time2str("%C", $F[1]))' file.log
    coffeeaddict_nl · 2009-08-13 13:57:33 0
  • This logs the titles of the active windows, thus you can monitor what you have done during which times. (it is not hard to also log the executable name, but then it is gets too long) Show Sample Output

    while true; do (echo -n $(date +"%F %T"):\ ; xwininfo -id $(xprop -root|grep "ACTIVE_WINDOW("|cut -d\ -f 5) | grep "Window id" | cut -d\" -f 2 ) >> logfile; sleep 60; done
    BeniBela · 2015-09-23 23:00:14 16
  • Really useful way to combine less and grep while browsing log files. I can't figure out how to make it into a true oneliner so paste it into a script file called lgrep: Usage: lgrep searchfor file1 [file2 file3] Advanced example (grep for an Exception in logfiles that starts with qc): lgrep Exception $(find . -name "qc*.log") Show Sample Output

    argv=("$@"); rest=${argv[@]:1}; less -JMN +"/$1" `grep -l $1 $rest`
    lassel · 2009-10-16 17:36:16 0
  • This command will return a full list of Error 404 pages in the given access log. The following variables have been given to awk Hostname ($2), ERROR Code ($9), Missing Item ($7), Referrer ($11) You can then send this into a file (>> /path/to/file), which you can open with OpenOffice as a CSV

    sudo awk '($9 ~ /404/)' /var/log/httpd/www.domain-access_log | awk '{print $2,$9,$7,$11}' | sort | uniq -c
    ninjasys · 2010-04-09 10:31:50 3

  • 1
    git log -p -z | perl -ln0e 'print if /[+-].*searchedstring/'
    takeshin · 2010-06-13 07:41:22 0
  • 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. Show Sample Output

    goaccess -f /var/log/apache2/access.log -s -b
    allinurl · 2010-10-25 20:03:18 3
  • * Replace USERNAME with the desired svn username * Replace the first YYYY-MM-DD with the date you want to get the log (this starts at the midnight event that starts this date) * Replace the second YYYY-MM-DD with the date after you want to get the log (this will end the log scan on midnight of the previous day) Example, if I want the log for December 10, 2010, I would put {2010-12-10}:{2010-12-11} Show Sample Output

    svn log -r '{YYYY-MM-DD}:{YYYY-MM-DD}' | sed -n '1p; 2,/^-/d; /USERNAME/,/^-/p' | grep -E -v '^(r[0-9]|---|$)' | sed 's/^/* /g'
    antic · 2010-12-22 17:52:19 1
  • This awk command prints a histogram of the number of times 'emergency' is the first word in a line, per day, in an irssi (IRC client) log file. Show Sample Output

    awk '/^--- Day changed (.*)/ {st=""; for (i=0;i<ar[date];i++) {st=st"*"} print date" "st; date=$7"-"$5"-"$6} /> emergency/ {ar[date]++} END {st=""; for (i=0;i<ar[date];i++) {st=st"*"}; print date" "st}' #engineyard.log
    menicosia · 2010-02-24 22:54:34 1
  • 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. Show Sample Output

    sed -n '/05\/Dec\/2010/,$ p' access.log | goaccess -s -b
    allinurl · 2010-12-13 17:37:33 0
  • The same with colors

    tail -f /var/log/squid/access.loc | ccze -CA
    longdrink · 2011-07-15 14:58:53 2
  • If you don't have html2text Show Sample Output

    curl -s '' | grep '<p>' | cut -c4-
    hputman · 2011-11-04 14:37:36 0
  • svn log -v --> takes log of all Filter1 -------- -r {from}{to} --> gives from and to revision Filter2 -------- awk of line 'r'with numbers Assign user=3rd column [ie; username] Filter3 -------- if username = George print details Filter4 -------- Print lines starts with M/U/G/C/A/D [* A Added * D Deleted * U Updated * G Merged * C Conflicted] Filter5 -------- sort all files Filter6 ------- Print only uniq file's name alone. Show Sample Output

    svn log -v -r{2009-11-1}:HEAD | awk '/^r[0-9]+ / {user=$3} /./{if (user=="george") {print}}' | grep -E "^ M|^ G|^ A|^ D|^ C|^ U" | awk '{print $2}' | sort | uniq
    smilyface · 2011-12-05 07:36:44 0
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-X Send the specified command to a running screen session. -S Option to specify the screen session if you have several screen sessions running. $screen -ls for listing current screens and its sessionname

Delete DOS Characters via VIM (^M)
And in case you want to migrate back to, err.. MS-DOS: ":set ff=dos" does the opposite.

Find all dot files and directories

Make changes in .bashrc immediately available
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gain all mp3s in subfolders w/o encoding
This will search all subfolders for mp3's and gain them to more or less sane defaults (without reencoding). required!

Get the full path of a bash script's Git repository head.
Rather than complicated and fragile paths relative to a script like "../../other", this command will retrieve the full path of the file's repository head. Safe with spaces in directory names. Works within a symlinked directory. Broken down: $cd "$(dirname "${BASH_SOURCE[0]}")" temporarily changes directories within this expansion. Double quoted "$(dirname" and ")" with unquoted ${BASH_SOURCE[0]} allows spaces in the path. $git rev-parse --show-toplevel gets the full path of the repository head of the current working directory, which was temporarily changed by the "cd".

list block devices
Shows all block devices in a tree with descruptions of what they are.

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