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commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.


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Universal configuration monitoring and system of record for IT.
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News

May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!
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Psst. Open beta.

Wow, didn't really expect you to read this far down. The latest iteration of the site is in open beta. It's a gentle open beta-- not in prime-time just yet. It's being hosted over at UpGuard (link) and you are more than welcome to give it a shot. Couple things:

  • » The open beta is running a copy of the database that will not carry over to the final version. Don't post anything you don't mind losing.
  • » If you wish to use your user account, you will probably need to reset your password.
Your feedback is appreciated via the form on the beta page. Thanks! -Jon & CLFU Team

All commands from sorted by
Terminal - All commands - 12,361 results
chage -l <user>
for u in `cut -f1 -d: /etc/passwd`; do echo -n $u:; groups $u; done | sort
2009-08-22 09:06:02
User: hemanth
Functions: echo groups
Tags: sort cut for groups
3

"cut" the user names from /etc/passwd and then running a loop over them.

find . -type d -empty -delete
2009-08-22 09:03:14
User: hemanth
Functions: find
Tags: find rmdir
6

You can also use, $ find . -depth -type d -exec rmdir {} \; 2>/dev/null

echo $(( $RANDOM % 10 + 1 ))
echo init 0 | at now + 2 hours
export PS1='\D{%a %D %T}> '
lsof -Pni4 | grep LISTEN
for i in `grep "unable to stat" /var/log/syslog | cut -d "/" -f 3 | sort | uniq`; do find /var/qmail/queue -name $i -type f -exec rm -v {} \; ; done
mailq | grep DrWEB | awk {'print $1'} | sed s/*//g | postsuper -d -
id=<XXXX>; find /var/spool/postfix/ -name $id -exec less {} \;
find /var/www/ -type f -name ".htaccess" -exec perl -pi -e 's/AddHandler[\s]*php(4|5)-cgi/AddHandler x-httpd-php\1/' {} \;
2009-08-21 21:55:22
User: foob4r
Functions: find perl
0

Alter "AddHandler php5-cgi .php" and "AddHandler php4-cgi .php" entries to new "AddHandler x-httpd-php5 .php" respective php4 entries in all .htaccess files under /var/www

echo "scale=4; 3 / 5" | bc
2009-08-21 21:51:46
User: foob4r
Functions: echo
3

allows you to use floating point operations in shell scripts

cat filename | tr '\n' '\0' | du -hsc ?files0-from=-
2009-08-21 18:36:49
User: Diluted
Functions: cat du tr
0

du only accepts lines ending with a NUL, which can be a pain to create. This solves that issue.

yes | tr 'y' 'n'
find dir/ -type f | xargs tail -fqn0
2009-08-21 18:05:12
User: chickenzilla
Functions: find tail xargs
1

The `-q' arg forces tail to not output the name of the current file

curl http://www.phrack.org/archives/tgz/phrack[1-67].tar.gz -o phrack#1.tar.gz
cc -march=native -E -v - </dev/null 2>&1 | grep cc1
2009-08-21 09:47:37
User: manny79
Functions: c++ cc grep
5

You can tell GCC to automatically select optimization commands and produce optimized code for the local machine (the one compiling the code), but you can't normally see what switches have been selected and used unless you append a "-v" and pause compilation.

uptime
pstree -p
1

Shows a less detailed output, made only of the process tree and their pids.

for ((i=1; i<67; i++)) do wget http://www.phrack.org/archives/tgz/phrack${i}.tar.gz -q; done
2009-08-20 23:27:01
User: Abiden
Functions: wget
0

This will download all the phracks! Enjoy!

watch -n .5 "iwlist wlan0 scan"
2009-08-20 23:05:04
User: Abiden
Functions: watch
1

If you're like some individuals who rely on ndiswrapper and cannot use kismet, this command may be of service.

watch -n .5 "iwlist wlan0 scan | egrep 'ESSID|Encryption'"

Or...

watch -n .5 "iwlist wlan0 scan | egrep 'ESSID|Encryption' | egrep 'linksys'"

:-) Hopefully you'll find some dd-wrt compatible routers.

sync; echo 3 > /proc/sys/vm/drop_caches
lynx http://shell-fu.org/
2009-08-20 11:47:35
User: penpen
-9

Today I learned that commandlinefu.com is not a alone in its conquest for further the knowledge about the command line. Allow me to introduce you to http://shell-fu.org/

watch() { t=$1; shift; while test :; do clear; date=$(date); echo -e "Every "$t"s: $@ \t\t\t\t $date"; $@; sleep $t; done }
( ( sleep 2h; your-command your-args ) & )
2009-08-19 17:39:11
User: sitaram
Functions: sleep
25

doesn't require "at", change the "2h" to whatever you want... (deafult unit for sleep is seconds)