Commands using read (340)


  • 2
    while read l; do echo -e "$RANDOM\t$l"; done | sort -n | cut -f 2
    unixmonkey28183 · 2011-12-09 01:02:27 4
  • The script gets the dimensions and position of a window and calls ffmpeg to record audio and video of that window. It saves it to a file named output.mkv Show Sample Output


    2
    echo "Click a window to start recording"; read x y W H <<< `xwininfo | grep -e Width -e Height -e Absolute | grep -oE "[[:digit:]]{1,}" | tr "\n" " "`; ffmpeg -f alsa -ac 1 -i pulse -f x11grab -s ${W}x${H} -r 25 -i :0.0+${x},${y} -sameq output.mkv
    joseCanciani · 2012-03-14 19:42:28 6
  • This command find which of your zip (or jar) files (when you have lots of them) contains a file you're searching for. It's useful when you have a lot of zip (or jar) files and need to know in which of them the file is archived. It's most common with .jar files when you have to know which of the .jar files contains the java class you need. To find in jar files, you must change "zip" to "jar" in the "find" command. The [internal file name] must be changed to the file name you're searching that is archived into one of the zip/jar files. Before run this command you must step into the directory that contains the zip or jar files.


    2
    find . -iname '*.zip' | while read file; do unzip -l "$file" | grep -q [internal file name] && echo $file; done
    ricardofunke · 2012-03-23 18:08:35 10
  • # find assumes email files start with a number 1-9 # sed joins the lines starting with " " to the previous line # gawk print the received and from lines # sort according to the second field (received+from) # uniq print the duplicated filename # a message is viewed as duplicate if it is received at the same time as another message, and from the same person. The command was intended to be run under cron. If run in a terminal, mutt can be used: mutt -e "push otD~=xq" -f $folder Show Sample Output


    2
    find $folder -name "[1-9]*" -type f -print|while read file; do echo $file $(sed -e '/^$/Q;:a;$!N;s/\n //;ta;s/ /_/g;P;D' $file|awk '/^Received:/&&!r{r=$0}/^From:/&&!f{f=$0}r&&f{printf "%s%s",r,f;exit(0)}');done|sort -k 2|uniq -d -f 1
    lpb612 · 2013-01-21 22:50:51 8
  • How much memory is chrome sucking? Show Sample Output


    2
    ps -e -m -o user,pid,args,%mem,rss | grep Chrome | perl -ne 'print "$1\n" if / (\d+)$/' | ( x=0;while read line; do (( x += $line )); done; echo $((x/1024)) );
    unixmonkey39631 · 2013-05-07 22:50:44 13
  • I tried a few curses based mp3 players for playing back choir practice songs for my wife. Unfortunately none of the ones I tried were capable of scrubbing a track. Firefox saves the day.


    2
    find . -name '*.mp3' | sort | while read -r mp3; do echo -e "<h3>$mp3</h3>\n<audio controls src=\"$mp3\"></audio>"; done > index.html; python -m http.server
    hendry · 2014-03-24 15:01:49 9
  • This is probably overkill, but I have some issues when the directories have spaces in their names. The find . -type d -print0 | while read -d $'\0' dir; do xxx; done loops over all the subdirectories in this place, ignoring the white spaces (to some extend). cd "$dir"; echo " process $dir"; cd -; goes to the directory and back. It also prints some info to check the progress. find . -maxdepth 1 -name "*.ogg.mp3" -exec rename 's/.ogg.mp3/.mp3/' {} \; renames the file within the current directory. The whole should work with directories and file names that include white spaces. Show Sample Output


    2
    find . -type d -print0 | while read -d $'\0' dir; do cd "$dir"; echo " process $dir"; find . -maxdepth 1 -name "*.ogg.mp3" -exec rename 's/.ogg.mp3/.mp3/' {} \; ; cd -; done
    bilbopingouin · 2014-08-25 11:28:43 8
  • replace all "?" characters in filename to underscore Show Sample Output


    2
    find . -type f -name "*\?*" | while read f;do mv "$f" "${f//[^0-9A-Za-z.\/\(\)\ ]/_}";done
    miccaman · 2014-11-28 14:55:27 12
  • Copy this function to command line, press 'Enter' 'f'' 'Enter' to execute (sentence on the left written only for newbies). Hint 'e|x|v|1..9' in front of displayed last modified file name means: "Press 'e' for edit,'x' for execute,'v' for view or a digit-key '1..9' to touch one file from the recent files list to be last modified" and suggested (hidden files are listed too, else remove 'a' from 'ls -tarp' statement if not intended). If you find this function useful you can then rename it if needed and append or include into your ~/.bashrc config script. With the command . ~/.bashrc the function then can be made immediately available. In the body of the function modifications can be made, i.e. replaced joe editor command or added new option into case statement, for example 'o) exo-open $h;;' command for opening file with default application - or something else (here could not be added since the function would exceed 255 chars). To cancel execution of function started is no need to press Ctrl-C - if the mind changed and want to leave simple Enter-press is enough. Once defined, this function can with typeset -f f command be displayed in easy readable form Show Sample Output


    2
    f() { ls -lart;e="ls -tarp|grep -v /|tail -9";j=${e/9/1};g=${e/9/9|nl -nln};h=$(eval $j);eval $g;read -p "e|x|v|1..9 $(eval $j)?" -n 1 -r;case $REPLY in e) joe $h;;v)cat $h;;x) eval $h;;[1-9]) s=$(eval $g|egrep ^$REPLY) && touch "${s:7}" && f;;esac ; }
    knoppix5 · 2019-09-26 11:58:37 239
  • This is a simple case of recursing through all directories, adding the '.bak' extension to every file. Of course, the 'cp $file $file.bak' could be any code you need to apply to your recursion, including tests, other functions, creating variables, doing math, etc. Simple and clean recursion.


    1
    find . -type f | while read file; do cp $file ${file}.bak; done
    atoponce · 2009-03-01 23:42:49 16

  • 1
    find . \( -type d -name .svn -prune \) -o -print | while read file ; do mergeinfo=`svn propget svn:mergeinfo $file` ; [ "$mergeinfo" != "" ] && echo -e "$file\n $mergeinfo\n" ; done
    troelskn · 2009-04-04 23:26:03 5
  • command | my_irc Pipe whatever you want to this function, it will, if everything goes well, be redirected to a channel or a user on an IRC server. Please note that : - I am not responsible of flood excesses you might provoke. - that function does not reply to PINGs from the server. That's the reason why I first write in a temporary file. Indeed, I don't want to wait for inputs while being connected to the server. However, according to the configuration of the server and the length of your file, you may timeout before finishing. - Concerning the server, the variable content must be on the form "irc.server.org 6667" (or any other port). If you want to make some tests, you can also create a fake IRC server on "localhost 55555" by using netcat -l -p 55555 - Concerning the target, you can choose a channel (beginning with a '#' like "#chan") or a user (like "user") - The other variables have obvious names. Show Sample Output


    1
    function my_irc { tmp=`mktemp`; cat > $tmp; { echo -e "USER $username x x :$ircname\nNICK $nick\nJOIN $target"; while read line; do echo -e "PRIVMSG $target :$line"; done < $tmp; } | nc $server > /dev/null ; rm $tmp; }
    Josay · 2009-06-11 22:14:48 7

  • 1
    md5sum * | sed 's/^\(\w*\)\s*\(.*\)/\2 \1/' | while read LINE; do mv $LINE; done
    opexxx · 2009-07-30 13:41:39 5
  • This version uses host and no ruby.


    1
    while read n; do host $n; done < list
    putnamhill · 2009-12-07 18:03:20 4
  • Prompts the user for username and password, that are then exported to http_proxy for use by wget, yum etc Default user, webproxy and port are used. Using this script prevent the cleartext user and pass being in your bash_history and on-screen Show Sample Output


    1
    set-proxy () { P=webproxy:1234; DU="fred"; read -p "username[$DU]:" USER; printf "%b"; UN=${USER:-$DU}; read -s -p "password:" PASS; printf "%b" "\n"; export http_proxy="http://${UN}:${PASS}@$P/"; export ftp_proxy="http://${UN}:${PASS}@$P/"; }
    shadycraig · 2010-02-04 13:12:59 5

  • 1
    find /dev/vg00 -type b |while read L; do lvextend -m 1 $L /dev/disk/<disk> ; done
    mobidyc · 2010-02-04 15:18:26 3
  • This one uses hex conversion to do the converting and is in shell/sed only (should probably still use the python/perl version).


    1
    uri_escape(){ echo -E "$@" | sed 's/\\/\\\\/g;s/./&\n/g' | while read -r i; do echo $i | grep -q '[a-zA-Z0-9/.:?&=]' && echo -n "$i" || printf %%%x \'"$i" done }
    infinull · 2010-02-13 01:39:51 41
  • hold period (or whatever character) and hit enter after a second. You need to make the next line of periods the same length as the previous line... score starts at 0 and increase each time length of line is same.


    1
    while $8;do read n;[ $n = "$l" ]&&c=$(($c+1))||c=0;echo $c;l=$n;done
    florian · 2010-03-31 00:41:08 28
  • The above is an example of grabbing only the first column. You can define the start and end points specifically by chacater position using the following command: while read l; do echo ${l:10:40}; done < three-column-list.txt > column-c10-c40.txt Of course, it doesn't have to be a column, or extraction, it can be replacement while read l; do echo ${l/foo/bar}; done < list-with-foo.txt > list-with-bar.txt Read more about parameter expansion here: http://wiki.bash-hackers.org/syntax/pe Think of this as an alternative to awk or sed for file operations


    1
    while read l; do echo ${l%% *}; done < three-column-list.txt > only-first-column.txt
    zed · 2010-07-09 03:42:56 3
  • This script compares the modification date of /var/lib/dpkg/info/${package}.list and all the files mentioned there. It could be wrong on noatime partitions. Here is non-oneliner: #!/bin/sh package=$1; list=/var/lib/dpkg/info/${package}.list; inst=$(stat "$list" -c %X); cat $list | ( while read file; do if [ -f "$file" ]; then acc=$(stat "$file" -c %X); if [ $inst -lt $acc ]; then echo used $file exit 0 fi; fi; done exit 1 ) Show Sample Output


    1
    package=$1; list=/var/lib/dpkg/info/${package}.list; inst=$(stat "$list" -c %X); cat $list | (while read file; do if [ -f "$file" ];then acc=$(stat "$file" -c %X); if [ $inst -lt $acc ]; then echo used $file; exit 0; fi; fi; done; exit 1)
    pipeliner · 2010-09-20 18:10:19 5

  • 1
    echo "12 morning\n15 afternoon\n24 evening" |while read t g; do if [ `date +%H` -lt $t ]; then echo "Good $g"; break; fi; done
    dendoes · 2010-09-23 13:06:10 5

  • 1
    find . -name "*.jar" | while read line; do unzip -l $line; done | grep your-string
    voidpointer · 2010-09-28 16:15:01 5
  • The given example collects output of the tail command: Whenever a line is emitted, further lines are collected, until no more output comes for one second. This group of lines is then sent as notification to the user. You can test the example with logger "First group"; sleep 1; logger "Second"; logger "group"


    1
    tail -f /var/log/messages | while read line; do accu="$line"; while read -t 1 more; do accu=`echo -e "$accu\n$more"`; done; notify-send "Syslog" "$accu"; done
    hfs · 2010-10-10 16:28:08 3
  • Increase the modification date for the files selected with the find command.


    1
    find . -type f | while read line; do NEW_TS=`date -d@$((\`stat -c '%Y' $line\` + <seconds> )) '+%Y%m%d%H%M.%S'`; touch -t $NEW_TS ${line}; done
    angleto · 2010-11-18 14:03:32 3
  • make, find and a lot of other programs can take a lot of time. And can do not. Supppose you write a long, complicated command and wonder if it will be done in 3 seconds or 20 minutes. Just add "R" (without quotes) suffix to it and you can do other things: zsh will inform you when you can see the results. You can replace zenity with other X Window dialogs program.


    1
    alias -g R=' &; jobs | tail -1 | read A0 A1 A2 cmd; echo "running $cmd"; fg "$cmd"; zenity --info --text "$cmd done"; unset A0 A1 A2 cmd'
    pipeliner · 2010-12-13 17:44:36 2
  • ‹ First  < 3 4 5 6 7 >  Last ›

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

Remount root in read-write mode.
Saved my day, when my harddrive got stuck in read-only mode.

most used unix commands

Convert CSV to JSON
Replace 'csv_file.csv' with your filename.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

how to export a table in .csv file
Exports the result of query in a csv file

List Threads by Pid along with Thread Start Time
This command will list all threads started by a particular pid along with the start time of each thread. This is very valuable when diagnosing thread leaks.

Create a tar archive using xz compression
Compress files or a directory to xz format. XZ has superior and faster compression than bzip2 in most cases. XZ is superior to 7zip format because it can save file permissions and other metadata data.

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Create a QR code image in MECARD format
Add the QR code image on your webpage, business card ., etc, so people can scan it and quick add to their Contact Address Book. Tested on iPhone with QRreader.


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: