Commands using echo (1,545)


  • -2
    echo "12345,12346" |sed -e's/ //'|tr "," "\n"| while read line; do echo -n $line" "; svn log -vr $line https://url/to/svn/repository/|grep "/"|head -1|cut -d"/" -f2; done
    psytek · 2009-04-15 15:21:20 4
  • You've opened a terminal window and you've connected off to a remote host that didn't pick up your terminal size, and all your curses and paging apps are screwed up as a result. You need to quickly determine how many lines are in your current terminal view (to feed into "stty rows X"). Show Sample Output


    -2
    _llines=100; while [ $_llines -gt 1 ]; do echo $_llines; _llines=$(($_llines-1)); done
    romulusnr · 2009-04-29 00:19:45 7
  • get desired info from machine and pipe it txt file. Show Sample Output


    -2
    echo "-------------" >> nicinfo.txt; echo "computer name x" >> nicinfo.txt; ifconfig | grep status >> nicinfo.txt; ifconfig | grep inet >> nicinfo.txt; ifconfig | grep ether >> nicinfo.txt; hostinfo | grep type >> nicinfo.txt;
    miccaman · 2009-06-25 12:32:37 31

  • -2
    wget http://checkip.dyndns.org && clear && echo && echo My IP && egrep -o '([[:digit:]]{1,3}\.){3}[[:digit:]]{1,3}' index.html && echo && rm index.html
    onkelchentobi · 2009-08-07 21:21:59 4

  • -2
    echo $PATH|awk -F: ' { for (i=1; i <= NF; i++) print $i }'
    nitins · 2009-08-12 07:56:56 4
  • Ummmm.. Saw that gem on some dead-head hippies VW bus at phish this summer.. It's actually one of my favorite ways of using bash, very clean. It shows what you can do with the cool advanced features like job control, redirection, combining commands that don't wait for each other, and the thing I like the most is the use of the ( ) to make this process heirarchy below, which comes in very handy when using fifos for adding optimization to your scripts or commands with similar acrobatics. F UID PID PPID WCHAN RSS PSR CMD 1 gplovr 30667 1 wait 1324 1 -bash 0 gplovr 30672 30667 - 516 3 \_ sleep 3 1 gplovr 30669 1 wait 1324 1 -bash 0 gplovr 30673 30669 - 516 0 \_ sleep 5 1 gplovr 30671 1 wait 1324 1 -bash 0 gplovr 30674 30671 - 516 1 \_ sleep 7 Show Sample Output


    -2
    S=$SSH_TTY && (sleep 3 && echo -n 'Peace... '>$S & ) && (sleep 5 && echo -n 'Love... '>$S & ) && (sleep 7 && echo 'and Intergalactic Happiness!'>$S & )
    AskApache · 2009-08-19 07:57:16 7
  • Enable 'sleep' function in Windows environment where this does not exist, although not exact in time. (there is a delay for each ping) This is a simple way to separate commands with a time-period. Show Sample Output


    -2
    echo sleep() begins: %TIME% && FOR /l %a IN (10,-1,1) do (ECHO 1 >NUL %as&ping -n 2 -w 1 127.0.0.1>NUL) && echo sleep() end: %TIME%
    pfredrik · 2009-08-19 13:43:09 3
  • If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.


    -2
    for i in 192.168.1.{61..71};do ping -c 1 $i &> /dev/null && echo $i;fi;done
    AlecSchueler · 2009-08-26 06:04:24 11
  • Removes trailing newline; colon becomes record separator and newline becomes field separator, only the first field is ever printed. Replaces empty entries with $PWD. Also prepend relative directories (like ".") with the current directory ($PWD). Can change PWD with env(1) to get tricky in (non-Bourne) scripts. Show Sample Output


    -2
    echo src::${PATH} | awk 'BEGIN{pwd=ENVIRON["PWD"];RS=":";FS="\n"}!$1{$1=pwd}$1!~/^\//{$1=pwd"/"$1}{print $1}'
    arcege · 2009-09-09 04:03:46 3
  • another replacement for cat.


    -2
    echo "$(</etc/issue)"
    mobidyc · 2009-09-14 09:44:35 34
  • regex to match an ip Show Sample Output


    -2
    echo "123.32.12.134" | grep -P '([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])\.([01]?\d\d?|2[0-4]\d|25[0-5])'
    KeePon · 2009-09-17 12:17:32 5

  • -2
    n=$RANDOM$RANDOM$RANDOM; let "n %= 10000000000"; echo $n
    alset · 2009-10-15 05:10:00 4
  • This script will list all the files in the tarballs present on any folder or subfolder of the provided path. The while loop is for echoing the file name of the tarball before listing the files, so the tarball can be identified


    -2
    find <path> -name "*.tgz" -or -name "*.tar.gz" | while read file; do echo "$file: "; tar -tzf $file; done
    polaco · 2009-11-10 20:39:04 36
  • If you gzip an empty file it becomes 20 bytes. Some backup checks i do check to see if the file is greater than zero size (-s flag) but this is no good here. Im sure someone has a better check than me for this? No check to see if file exists before checking it's size.


    -2
    BACKUP_FILE_SIZE=`eval ls -l ${BACKUP_FILE} | awk {'print $5'}`; if [ $BACKUP_FILE_SIZE -le 20 ]; then echo "its empty"; else echo "its not empty"; fi
    Redrocket · 2009-12-29 08:34:37 3
  • CHANGELOG Version 1.1 removedir () { echo "You are about to delete the current directory $PWD Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=$(echo "$PWD" | sed 's/ /\\ /g'); foo=$(basename "$blah"); rm -Rf ../$foo/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; } BUG FIX: Folders with spaces Version 1.0 removedir () { echo "You are about to delete the current directory $PWD Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=`basename $PWD`; rm -Rf ../$blah/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; } BUG FIX: Hidden directories (.dotdirectory) Version 0.9 rmdir () { echo "You are about to delete the current directory $PWD. Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=`basename $PWD`; rm -Rf ../$blah/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; } Removes current directory with recursive and force flags plus basic human check. When prompted type yes 1. [user@host ~]$ ls foo bar 2. [user@host ~]$ cd foo 3. [user@host foo]$ removedir 4. yes 5. rm -Rf foo/ 6. [user@host ~]$ 7. [user@host ~]$ ls bar Show Sample Output


    -2
    removedir () { echo "Deleting the current directory $PWD Are you sure?"; read human; if [[ "$human" = "yes" ]]; then blah=$(echo "$PWD" | sed 's/ /\\ /g'); foo=$(basename "$blah"); rm -Rf ../$foo/ && cd ..; else echo "I'm watching you" | pv -qL 10; fi; }
    oshazard · 2010-01-17 11:34:38 31
  • Outputs multiple whois from a plain text file.


    -2
    for domain in `cat list_of_domains.txt`; do echo $domain; whois $domain >> output.txt; done
    pathcl · 2010-02-15 17:13:45 7
  • You don't want the -ar parameters in this case. The man page for BASH_BUILTINS(1) states: "-a option means to remove or mark all jobs" and "-r option without a jobspec argument restricts operation to running jobs" In this case we are supplying the process id of the job to disown so neither of these should be used.


    -2
    echo "Starting Daemon"; ( while :; do sleep 15; echo "I am still running =]"; done ) & disown -h $!
    daleki · 2010-02-23 19:17:05 3
  • find all files in cur dir add to url and append to file


    -2
    find . type f -exec echo http://exg.com/{} \; > file
    unixmonkey8504 · 2010-03-02 14:18:01 3
  • Tested on bash, and follows all the rules about leap years. Show Sample Output


    -2
    leapyear() { if [ $[$1 % 4] -eq 0 ] && [ $[$1 % 100] -ne 0 ] || [ $[$1 % 400] -eq 0 ]; then echo $1' is a leap year!'; else echo $1' is not a leap year.'; fi; }
    kaedenn · 2010-03-30 17:19:20 4
  • Not really an easier solution. But an example using && for (if last command returned 0). You can use || for (if last command returned other than 0).. Show Sample Output


    -2
    prefix="10.0.0" && for i in `seq 25`; do ping -c 1 $prefix.$i &> /dev/null && echo "Answer from: $prefix.$i" ; done
    xeor · 2010-04-07 17:17:21 4
  • Some servers don't have ssh-copy-id, this works in those cases. It will ask for the destination server, this can be IP, hostname, or user@hostname if different from current user. Ssh keygen will let you know if a pubkey already exists on your system and you can opt to not overwrite it.


    -2
    echo 'Host or User@Host?:'; read newserver && ssh-keygen -N "" -t rsa -f ~/.ssh/id_rsa ; ssh $newserver cat <~/.ssh/id_rsa.pub ">>" ~/.ssh/authorized_keys ; ssh $newserver
    alf · 2010-05-07 06:24:53 4
  • Currently Facebook has updated their headers to display 127.0.0.1 but if you have saved e-mails from messages and FB related mail you can still reveal the IP. :) Tested on Mac OS X 10.6.3 Show Sample Output


    -2
    echo "X-Facebook: from zuckmail ([MTI3LjAuMC4x])" | cut -d \[ -f 2 | cut -d \] -f 1 | openssl base64 -d
    IsraelTorres · 2010-05-09 00:46:28 4
  • simple bash one liner to pass multiple arguments to command one by one. optional yes/no pipe at beginning of command Show Sample Output


    -2
    yes|for x in one two three; do echo result - $x; done
    Panikos · 2010-06-01 14:49:29 3
  • Instead of having someone else read you the Digg headlines, Have OSX do it. Requires Curl+Sed+Say. This could probably be easily modified to use espeak for Linux.


    -2
    IFS=`echo -en "\n\b"`; for i in $(curl http://feeds.digg.com/digg/container/technology/popular.rss | grep '<title>' | sed -e 's#<[^>]*>##g' | tail -n10); do echo $i; echo $i | sed 's/^/Did you hear about /g' | say; sleep 30; done
    echosedawk · 2010-06-07 22:16:19 4

  • -2
    for i in 192.168.1.{1..254} ; do if ping -c1 -w1 $i &>/dev/null; then echo $i alive; fi; done
    wiburg · 2010-06-12 18:38:36 3
  • ‹ First  < 54 55 56 57 58 >  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

Search recursively to find a word or phrase in certain file types, such as C code
I have a bash alias for this command line and find it useful for searching C code for error messages. The -H tells grep to print the filename. you can omit the -i to match the case exactly or keep the -i for case-insensitive matching. This find command find all .c and .h files

List your installed Chromium extensions (with url to each page)
Gives you a list for all installed chrome (chromium) extensions with URL to the page of the extension. With this you can easy add a new Bookmark folder called "extensions" add every URL to that folder, so it will be synced and you can access the names from every computer you are logged in. ------------------------------------------------------------------------------------------------------------------ Only tested with chromium, for chrome you maybe have to change the find $PATH.

Convert Squid unixtime logs in human-readable ones
On-the-fly conversion of Unix Time to human-readable in Squid's access.log

Recursively remove all empty directories

Run a command multiple times with different subcommands
it's nice to be able to use the command `ls program.{h,c,cpp}`. This expands to `ls program.h program.c program.cpp`. Note: This is a text expansion, not a shell wildcard type expansion that looks at matching file names to calculate the expansion. More details at http://www.linuxjournal.com/content/bash-brace-expansion I often run multiple commands (like apt-get) one after the other with different subcommands. Just for fun this wraps the whole thing into a single line that uses brace expansion.

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

sed /pat/!d without using sed (no RE; limited to shell patterns aka globbing)
POSIX requires this "string truncating" functionality. might as well use it, at least for very small tasks where invoking sed and using RE is overkill.

Silently ensures that a FS is mounted on the given mount point (checks if it's OK, otherwise unmount, create dir and mount)
In my example, the mount point is /media/mpdr1 and the FS is /dev/sdd1 /mountpoint-path = /media/mpdr1 filesystem=/dev/sdd1 Why this command ? Well, in fact, with some external devices I used to face some issues : during data transfer from the device to the internal drive, some errors occurred and the device was unmounted and remounted again in a different folder. In such situations, the command mountpoint gave a positive result even if the FS wasn't properly mounted, that's why I added the df part. And if the device is not properly mounted, the command tries to unmount, to create the folder (if it exists already it will also work) and finally mount the FS on the given mount point.

List all databases in Postgres and their (byte/human) sizes, ordering by byte size descending
Get a listing of all of your databases in Postgres and their sizes, ordering by the largest size first. Requires that you give the -d parameter a valid database name that you can connect to.

print a python-script (or any other code) with syntax-highlighting and no loss of indentation


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: