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2011-03-12 - Confoo 2011 presentation
Slides are available from the commandlinefu presentation at Confoo 2011: http://presentations.codeinthehole.com/confoo2011/
2011-01-04 - Moderation now required for new commands
To try and put and end to the spamming, new commands require moderation before they will appear on the site.
2010-12-27 - Apologies for not banning the trolls sooner
Have been away from the interwebs over Christmas. Will be more vigilant henceforth.
2010-09-24 - OAuth and pagination problems fixed
Apologies for the delay in getting Twitter's OAuth supported. Annoying pagination gremlin also fixed.




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Terminal - All commands - 11,856 results
curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | sed -n "s/<title>\(.*\)<\/title.*name>\(.*\)<\/name>.*/\2 - \1/p"
2009-09-07 21:56:40
User: postrational
Functions: awk sed tr

Checks the Gmail ATOM feed for your account, parses it and outputs a list of unread messages.

For some reason sed gets stuck on OS X, so here's a Perl version for the Mac:

curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | perl -pe 's/^<title>(.*)<\/title>.*<name>(.*)<\/name>.*$/$2 - $1/'

If you want to see the name of the last person, who added a message to the conversation, change the greediness of the operators like this:

curl -u username:password --silent "https://mail.google.com/mail/feed/atom" | tr -d '\n' | awk -F '<entry>' '{for (i=2; i<=NF; i++) {print $i}}' | perl -pe 's/^<title>(.*)<\/title>.*?<name>(.*?)<\/name>.*$/$2 - $1/'
cmdfu(){ curl "http://www.commandlinefu.com/commands/matching/$@/$(echo -n $@ | openssl base64)/plaintext"; }
dd if=/dev/zero of=/dev/null bs=1M count=32768
2009-02-16 12:22:18
Functions: dd

Read 32GB zero's and throw them away.

How fast is your system?

for code in {0..255}; do echo -e "\e[38;05;${code}m $code: Test"; done
2010-06-19 02:14:42
User: scribe
Functions: echo
Tags: bash color colors

Same as http://www.commandlinefu.com/commands/view/5876, but for bash.

This will show a numerical value for each of the 256 colors in bash. Everything in the command is a bash builtin, so it should run on any platform where bash is installed. Prints one color per line. If someone is interested in formatting the output, paste the alternative.

chmod --reference file1 file2
2010-03-31 12:05:48
User: rpavlick
Functions: chmod
Tags: chmod chown chgrp

Also works with:

chgrp --reference file1 file2 chown --reference file1 file2
ssh -t remote_host screen -r
2009-07-23 06:15:04
User: recursiverse
Functions: screen ssh
Tags: ssh screen

Directly attach a remote screen session (saves a useless parent bash process)

ssh -t hostA ssh hostB
2009-08-27 21:35:19
User: 0x89
Functions: ssh

Of course you need to be able to access host A for this ;-)

ssh -MNf <user>@<host>
2009-02-26 14:11:19
User: raphink
Functions: ssh

Create a persistent SSH connection to the host in the background. Combine this with settings in your ~/.ssh/config:

Host host

ControlPath ~/.ssh/master-%r@%h:%p

ControlMaster no

All the SSH connections to the machine will then go through the persisten SSH socket. This is very useful if you are using SSH to synchronize files (using rsync/sftp/cvs/svn) on a regular basis because it won't create a new socket each time to open an ssh connection.

dpkg -S /usr/bin/ls
2009-04-18 18:18:23
User: bwoodacre

'dpkg -S' just matches the string you supply it, so just using 'ls' as an argument matches any file from any package that has 'ls' anywhere in the filename. So usually it's a good idea to use an absolute path. You can see in the second example that 12 thousand files that are known to dpkg match the bare string 'ls'.

bind -P
2012-05-28 18:51:59
User: ricardofunke

This command shows the various shortcuts that can be use in bash, including Ctrl+L, Ctrl+R, etc...

You can translate "\C-y" to Ctrl+y, for example.

gs -q -dNOPAUSE -dBATCH -sDEVICE=pdfwrite -sOutputFile=OUTPUT.pdf -c .setpdfwrite -f INPUT.pdf
2009-12-14 21:30:22
User: deijmaster
Functions: gs

Remove security from PDF document using this very simple command on Linux and OSX. You need ghostscript for this baby to work.

ps awwfux | less -S
2009-07-04 09:39:28
User: ToyKeeper
Functions: less ps

If you want a visual representation of the parent/child relationships between processes, this is one easy way to do it. It's useful in debugging collections of shell scripts, because it provides something like a call traceback.

When a shell script breaks, just remember "awwfux".

% screen -r someuser/
2009-03-25 23:59:38
User: totoro
Functions: screen

If you enable multiuser, then you can permit others to share your screen session. The following conditions apply:

1. screen must be suid root;

2. "multiuser on" must be configured in ~/.screenrc;

3. control the others user(s) access with "aclchg":

# ----- from ~/.screenrc-users -----

aclchg someuser +rx "#?" #enable r/o access to "someuser"

aclchg someuser -x "#,at,aclchg,acladd,acldel,quit" # don't allow these

aclchg otheruser +rwx "#?" # enable r/w access to "otheruser"

aclchg otheruser -x "#,at,aclchg,acladd,acldel,quit" # don't allow them to use these commands

# -----

After doing this (once), you start your session with:

$ screen

Then, the other user can join your terminal session(s) with youruserid:

$ screen -r youruserid/

Note: the trailing "/" is required.

Multiple users can share the same screen simultaneously, each with independent access controlled precisely with "aclchg" in the ~/.screenrc file.

I use the following setup:

# ~/.screenrc-base

# default screenrc on any host

source $HOME/.screenrc-base

source $HOME/.screenrc-$HOST

source $HOME/.screenrc-users

# -----

Then, the base configurations are in ~/.screenrc-base; the host-specific configurations are in ~/.screenrc-$HOST, and the user configurations are in ~/.screenrc-users.

The host-specific .screenrc file might contain some host-specific screen commands; e.g.:

# ~/.screen-myhost

# -----

screen -t 'anywhere' /bin/tcsh

screen -t 'anywhere1' /bin/tcsh

# ----

The .screenrc-base contains:

# ~/.screenrc-base

## I find typing ^a (Control-a) awkward. So I set the escape key to CTRL-j instead of a.

escape ^Jj

termcapinfo xterm* ti@:te@:

autodetach on

zombie kr

verbose on

multiuser on

echo "rm -rf /unwanted-but-large/folder" | batch
2009-02-04 19:07:52
User: root
Functions: echo

Good for one off jobs that you want to run at a quiet time. The default threshold is a load average of 0.8 but this can be set using atrun.

wget http://www.youtube.com/watch?v=dQw4w9WgXcQ -qO- | sed -n "/fmt_url_map/{s/[\'\"\|]/\n/g;p}" | sed -n '/^fmt_url_map/,/videoplayback/p' | sed -e :a -e '$q;N;5,$D;ba' | tr -d '\n' | sed -e 's/\(.*\),\(.\)\{1,3\}/\1/' | wget -i - -O surprise.flv
2011-01-25 04:19:06
User: Eno
Functions: sed tr wget

Nothing special required, just wget, sed & tr!

script -qf | tee >(nc -kl 5000) >(nc -kl 5001) >(nc -kl 5002)
2010-10-11 07:55:30
User: clvv
Functions: script tee
Tags: tee pipe script nc

run 'nc yourip 5000', 'nc yourip 5001' or 'nc yourip 5002' elsewhere will produce an exact same mirror of your shell. This is handy when you want to show someone else some amazing stuff in your shell without giving them control over it.

sudo touch /forcefsck
2009-10-29 17:04:47
User: johnraff
Functions: sudo touch

The empty file /forcefsck causes the file system check fsck to be run next time you boot up, after which it will be removed.

This works too:

sudo >/forcefsck
sed -n 5p <file>
2009-10-15 11:00:48
User: Waldirio
Functions: sed

You can get one specific line during any procedure. Very interesting to be used when you know what line you want.

ls -d */
2009-10-08 22:07:22
User: brianmuckian
Functions: ls

-d: list directory entries instead of contents, and do not dereference symbolic links

rtfm() { help $@ || man $@ || $BROWSER "http://www.google.com/search?q=$@"; }
google docs edit --title "To-Do List" --editor vim
2010-06-21 16:15:42
User: spiffwalker
Tags: google

Google just released a new commend line tool offering all sorts of new services from the commend line. One of them is uploading a youtube video but there are plenty more google services to interact with.

Download it here: http://code.google.com/p/googlecl/

Manual: http://code.google.com/p/googlecl/wiki/Manual

This specific command courtesy of lifehacker:http://lifehacker.com/5568817/

Though all can be found in manual page linked above.

grep -RnisI <pattern> *
2009-09-22 15:09:43
User: birnam
Functions: grep
Tags: bash grep

This is how I typically grep. -R recurse into subdirectories, -n show line numbers of matches, -i ignore case, -s suppress "doesn't exist" and "can't read" messages, -I ignore binary files (technically, process them as having no matches, important for showing inverted results with -v)

I have grep aliased to "grep --color=auto" as well, but that's a matter of formatting not function.

tar -tf <file.tar.gz> | xargs rm -r
lsmod | perl -e 'print "digraph \"lsmod\" {";<>;while(<>){@_=split/\s+/; print "\"$_[0]\" -> \"$_\"\n" for split/,/,$_[3]}print "}"' | dot -Tpng | display -
2011-11-27 14:02:35
User: bandie91
Functions: dot lsmod perl

parse `lsmod' output and pass to `dot' drawing utility then finally pass it to an image viewer