Commands using awk (1,418)

  • Display connections histogram

    Displays a connection histogram of active tcp connections. Works even better under an alias. Thanks @Areis1 for sharing this one.


    7
    netstat -an | grep ESTABLISHED | awk '\''{print $5}'\'' | awk -F: '\''{print $1}'\'' | sort | uniq -c | awk '\''{ printf("%s\t%s\t",$2,$1); for (i = 0; i < $1; i++) {printf("*")}; print ""}'\''
    mramos · 2010-07-09 00:25:45 42
  • Remove all unused kernels with apt-get

    Note the double space: "...^ii␣␣linux-image-2..." Like 5813, but fixes two bugs: [1]This leaves the meta-packages 'linux-headers-generic' and 'linux-image-generic' alone so that automatic upgrades work correctly in the future. [2]Kernels newer than the currently running one are left alone (this can happen if you didn't reboot after installing a new kernel). I'm bummed that this took 228 characters. I'd like to see a simpler version. Show Sample Output


    7
    aptitude remove $(dpkg -l|awk '/^ii linux-image-2/{print $2}'|sed 's/linux-image-//'|awk -v v=`uname -r` 'v>$0'|sed 's/-generic//'|awk '{printf("linux-headers-%s\nlinux-headers-%s-generic\nlinux-image-%s-generic\n",$0,$0,$0)}')
    __ · 2010-12-11 11:38:15 7
  • easily strace all your apache processes

    This one-liner will use strace to attach to all of the currently running apache processes output and piped from the initial "ps auxw" command into some awk. Show Sample Output


    7
    ps auxw | grep sbin/apache | awk '{print"-p " $2}' | xargs strace
    px · 2011-03-14 21:45:22 34
  • Load average + API google chart

    limite = threshold Show Sample Output


    7
    limite="5";load5=$(awk '{print $1}' /proc/loadavg);echo "http://chart.apis.google.com/chart?chxr=0,0,5&chxt=y&chs=700x240&cht=gm&chds=0,"$limite"&chd=t:"$load5"&chl="$load5"&chtt=$(hostname)+load+average"
    ncaio · 2011-04-02 17:55:24 8
  • Check how far along (in %) your program is in a file

    Imagine you've started a long-running process that involves piping data, but you forgot to add the progress-bar option to a command. e.g. xz -dc bigdata.xz | complicated-processing-program > summary . This command uses lsof to see how much data xz has read from the file. lsof -o0 -o -Fo FILENAME Display offsets (-o), in decimal (-o0), in parseable form (-Fo) This will output something like: . p12607 f3 o0t45187072 . Process id (p), File Descriptor (f), Offset (o) . We stat the file to get its size stat -c %s FILENAME . Then we plug the values into awk. Split the line at the letter t: -Ft Define a variable for the file's size: -s=$(stat...) Only work on the offset line: /^o/ . Note this command was tested using the Linux version of lsof. Because it uses lsof's batch option (-F) it may be portable. . Thanks to @unhammer for the brilliant idea. Show Sample Output


    7
    F=bigdata.xz; lsof -o0 -o -Fo $F | awk -Ft -v s=$(stat -c %s $F) '/^o/{printf("%d%%\n", 100*$2/s)}'
    flatcap · 2015-09-19 22:22:43 18
  • Count the number of queries to a MySQL server


    6
    echo "SHOW PROCESSLIST\G" | mysql -u root -p | grep "Info:" | awk -F":" '{count[$NF]++}END{for(i in count){printf("%d: %s\n", count[i], i)}}' | sort -n
    bpfx · 2009-02-05 14:24:20 40
  • Display any tcp connections to apache

    Sometimes apache will get stuck in an established state where you can't get a list of the connecting IP's from mod_status... not a good thing when you need to ban an abusive ip.


    6
    for i in `ps aux | grep httpd | awk '{print $2}'`; do lsof -n -p $i | grep ESTABLISHED; done;
    Shadow · 2009-02-05 17:50:52 67
  • Octal ls

    Do ls with permissions written in octal form. Show Sample Output


    6
    ls -l | awk '{k=0;for(i=0;i<=8;i++)k+=((substr($1,i+2,1)~/[rwx]/)*2^(8-i));if(k)printf("%0o ",k);print}'
    iArno · 2009-02-13 19:20:54 21
  • Display the standard deviation of a column of numbers with awk


    6
    awk '{sum+=$1; sumsq+=$1*$1} END {print sqrt(sumsq/NR - (sum/NR)**2)}' file.dat
    kaan · 2009-03-24 21:56:40 9
  • List top ten files/directories sorted by size


    6
    du -sb *|sort -nr|head|awk '{print $2}'|xargs du -sh
    srand · 2009-05-12 19:58:45 9
  • Hostname tab-completion for ssh

    This is meant for the bash shell. Put this function in your .profile and you'll be able to use tab-completion for sshing any host which is in your known_hosts file. This assumes that your known_hosts file is located at ~/.ssh/known_hosts. The "complete" command should go on a separate line as such: function autoCompleteHostname() { local hosts=($(awk '{print $1}' ~/.ssh/known_hosts | cut -d, -f1)); local cur=${COMP_WORDS[COMP_CWORD]}; COMPREPLY=($(compgen -W '${hosts[@]}' -- $cur )) } complete -F autoCompleteHostname ssh


    6
    function autoCompleteHostname() { local hosts; local cur; hosts=($(awk '{print $1}' ~/.ssh/known_hosts | cut -d, -f1)); cur=${COMP_WORDS[COMP_CWORD]}; COMPREPLY=($(compgen -W '${hosts[@]}' -- $cur )) } complete -F autoCompleteHostname ssh
    sbisordi · 2009-05-17 23:12:34 10
  • Check which files are opened by Firefox then sort by largest size.

    Check which files are opened by Firefox then sort by largest size (in MB). You can see all files opened by just replacing grep to "/". Useful if you'd like to debug and check which extensions or files are taking too much memory resources in Firefox. Show Sample Output


    6
    FFPID=$(pidof firefox-bin) && lsof -p $FFPID | awk '{ if($7>0) print ($7/1024/1024)" MB -- "$9; }' | grep ".mozilla" | sort -rn
    josue · 2009-08-16 08:58:22 7
  • Compute running average for a column of numbers

    This is an on-line algorithm for calculating the mean value for numbers in a column. Also known as "running average" or "moving average".


    6
    awk '{avg += ($1 - avg) / NR;} END { print avg; }'
    ashawley · 2009-09-10 17:06:03 7
  • Visualizing system performance data


    6
    (echo "set terminal png;plot '-' u 1:2 t 'cpu' w linespoints;"; sudo vmstat 2 10 | awk 'NR > 2 {print NR, $13}') | gnuplot > plot.png
    grokskookum · 2009-09-23 16:40:13 12
  • sort lines by length


    6
    awk '{print length, $0;}' | sort -nr
    ashawley · 2009-10-07 16:32:27 4
  • Print Memory Utilization Percentage For a specific process and it's children

    Change the name of the process and what is echoed to suit your needs. The brackets around the h in the grep statement cause grep to skip over "grep httpd", it is the equivalent of grep -v grep although more elegant. Show Sample Output


    6
    TOTAL_RAM=`free | head -n 2 | tail -n 1 | awk '{ print $2 }'`; PROC_RSS=`ps axo rss,comm | grep [h]ttpd | awk '{ TOTAL += $1 } END { print TOTAL }'`; PROC_PCT=`echo "scale=4; ( $PROC_RSS/$TOTAL_RAM ) * 100" | bc`; echo "RAM Used by HTTP: $PROC_PCT%"
    d34dh0r53 · 2010-02-26 20:29:45 8
  • List .log files open by a pid

    Uses lsof to display the full path of ".log" files opened by a specified PID.


    6
    lsof -p 1234 | grep -E "\.log$" | awk '{print $NF}'
    zlemini · 2010-03-05 11:41:28 5
  • Capture video of a linux desktop


    6
    ffmpeg -f x11grab -s `xdpyinfo | grep 'dimensions:'|awk '{print $2}'` -r 25 -i :0.0 -sameq /tmp/out.mpg > /root/howto/capture_screen_video_ffmpeg
    brubaker · 2010-03-27 21:31:34 5
  • processes per user counter

    enumerates the number of processes for each user. ps BSD format is used here , for standard Unix format use : ps -eLf |awk '{$1} {++P[$1]} END {for(a in P) if (a !="UID") print a,P[a]}' Show Sample Output


    6
    ps aux |awk '{$1} {++P[$1]} END {for(a in P) if (a !="USER") print a,P[a]}'
    benyounes · 2010-04-28 15:25:18 3
  • Determine if photos have been rotated to portrait orientation instead of normal landscape orientation

    Most people take photos in landscape orientation (wider than it is tall). Sometimes though you turn the camera sideways to capture a narrow/tall subject. Assuming you then manually rotate those picture files 90 degrees for proper viewing on screen or photo frame, you now have a mix of orientations in your photos directory. This command will print out the names of all the photos in the current directory whose vertical resolution is larger than its horizontal resolution (i.e. portrait orientation). You can then take that list of files and deal with them however you need to, like re-rotating back to landscape for consistent printing with all the others. This command requires the "identify" command from the ImageMagick command-line image manipulation suite. Sample output from identify: identify PICT2821.JPG PICT2821.JPG JPEG 1536x2048 1536x2048+0+0 8-bit DirectClass 688KB 0.016u 0:00.006 Show Sample Output


    6
    for i in *; do identify $i | awk '{split($3,a,"x"); if (a[2]>a[1]) print $1;}'; done
    dmmst19 · 2014-05-27 23:41:24 10
  • Find dupe files by checking md5sum


    6
    find /glftpd/site/archive -type f|grep '([0-9]\{1,9\})\.[^.]\+$'|parallel -n1 -j200% md5sum ::: |awk 'x[$1]++ { print $2 " :::"}'|sed 's/^/Dupe: /g'|sed 's,Dupe,\x1B[31m&\x1B[0m,'
    wuseman1 · 2019-10-22 16:02:15 150
  • Save a copy of all debian packages in the form in which they are installed and configured on your system

    A copy of all installed debian packages on your system will be put back together, with all changes in configuration files you made and placed in the current directory. Make sure you have enough disk space (say 2-3 GB). Break any time with Ctrl+C. Show Sample Output


    6
    for a in $(sudo dpkg --get-selections|cut -f1); do dpkg-repack $a|awk '{if (system("sleep .5 && exit 2") != 2) exit; print}';done
    knoppix5 · 2021-01-17 17:07:02 333
  • Count the number of characters in each line


    5
    awk '{count[length]++}END{for(i in count){printf("%d: %d\n", count[i], i)}}'
    bpfx · 2009-02-05 14:20:39 26
  • Find all the files more than 10MB, sort in descending order of size and record the output of filenames and size in a text file.

    This command specifies the size in Kilobytes using 'k' in the -size +(N)k option. The plus sign says greater than. -exec [cmd] {} \; invokes ls -l command on each file and awk strips off the values of the 5th (size) and the 9th (filename) column from the ls -l output to display. Sort is done in reversed order (descending) numerically using sort -rn options. A cron job could be run to execute a script like this and alert the users if a dir has files exceeding certain size, and provide file details as well. Show Sample Output


    5
    find . -size +10240k -exec ls -l {} \; | awk '{ print $5,"",$9 }'|sort -rn > message.out
    rommelsharma · 2009-02-17 19:39:56 10
  • restore the contents of a deleted file for which a descriptor is still available

    Note that the file at the given path will have the contents of the (still) deleted file, but it is a new file with a new node number; in other words, this restores the data, but it does not actually "undelete" the old file. I posted a function declaration encapsulating this functionality to http://www.reddit.com/r/programming/comments/7yx6f/how_to_undelete_any_open_deleted_file_in_linux/c07sqwe (please excuse the crap formatting).


    5
    N="filepath" ; P=/proc/$(lsof +L1 | grep "$N" | awk '{print $2}')/fd ; ls -l $P | sed -rn "/$N/s/.*([0-9]+) ->.*/\1/p" | xargs -I_ cat $P/_ > "$N"
    laburu · 2009-02-21 02:31:24 28
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Find and display most recent files using find and perl
This pipeline will find, sort and display all files based on mtime. This could be done with find | xargs, but the find | xargs pipeline will not produce correct results if the results of find are greater than xargs command line buffer. If the xargs buffer fills, xargs processes the find results in more than one batch which is not compatible with sorting. Note the "-print0" on find and "-0" switch for perl. This is the equivalent of using xargs. Don't you love perl? Note that this pipeline can be easily modified to any data produced by perl's stat operator. eg, you could sort on size, hard links, creation time, etc. Look at stat and just change the '9' to what you want. Changing the '9' to a '7' for example will sort by file size. A '3' sorts by number of links.... Use head and tail at the end of the pipeline to get oldest files or most recent. Use awk or perl -wnla for further processing. Since there is a tab between the two fields, it is very easy to process.

Put public IP address in a variable

list files recursively by size

Scans for open ports using telnet

Efficient count files in directory (no recursion)
$ time perl -e 'if(opendir D,"."){@a=readdir D;print $#a - 1,"\n"}' 205413 real 0m0.497s user 0m0.220s sys 0m0.268s $ time { ls |wc -l; } 205413 real 0m3.776s user 0m3.340s sys 0m0.424s ********* ** EDIT: turns out this perl liner is mostly masturbation. this is slightly faster: $ find . -maxdepth 1 | wc -l sh-3.2$ time { find . -maxdepth 1|wc -l; } 205414 real 0m0.456s user 0m0.116s sys 0m0.328s ** EDIT: now a slightly faster perl version $ perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' sh-3.2$ time perl -e 'if(opendir D,"."){++$c foreach readdir D}print $c-1,"\n"' 205414 real 0m0.415s user 0m0.176s sys 0m0.232s

Create a thumbnail from a video file

Monitor memory fine-grained usage (e.g. firefox)
Sometimes top/htop don't give the fine-grained detail on memory usage you might need. Sum up the exact memory types you want

Clear terminal Screen

user 'tr' to convert mixed case in a file to lower case
convert mixed case in a file to lower case

drop first column of output by piping to this

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