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.
You can sign-in using OpenID credentials, or register a traditional username and password.
First-time OpenID users will be automatically assigned a username which can be changed after signing in.
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
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:
this command will add the following two lines into the ~/.bash_aliases:
alias exit='pwd > ~/.lastdir;exit'
[ -n "$(cat .lastdir 2>/dev/null)" ] && cd "$(cat .lastdir)"
or redirect it to the ~/.bashrc if you like
Donno, I find it usefull. You may also define an alias for 'cd ~' like - alias cdh='cd ~'
Since none of the systems I work on have readlink, this works cross-platform (everywhere has perl, right?).
Note: This will resolve links.
Use the -a flag to display all files, including hidden files. If you just want to display regular files, use a -1 (yes, that is the number one). Got this by RTFM and adding some sed magic.
[[email protected] ~]$ ls -a | sed "s#^#${PWD}/#"
/home/bbbco/.
/home/bbbco/..
/home/bbbco/2011-09-01-00-33-02.073-VirtualBox-2934.log
/home/bbbco/2011-09-10-09-49-57.004-VirtualBox-2716.log
/home/bbbco/.adobe
/home/bbbco/.bash_history
/home/bbbco/.bash_logout
/home/bbbco/.bash_profile
/home/bbbco/.bashrc
...
[[email protected] ~]$ ls -1 | sed "s#^#${PWD}/#"
/home/bbbco/2011-09-01-00-33-02.073-VirtualBox-2934.log
/home/bbbco/2011-09-10-09-49-57.004-VirtualBox-2716.log
/home/bbbco/cookies.txt
/home/bbbco/Desktop
/home/bbbco/Documents
/home/bbbco/Downloads
...
Also resolves symlinks, showing the full path of the link target
Sometimes you need the full path to your script, regardless of how it was executed (which starting directory) in order to maintain other relative paths in the script.
If you attempt to just use something simple like:
STARTING_DIR="${0%/*}"
you will only get the relative path depending on where you first executed the script from.
You can get the relative path to the script (from your starting point) by using dirname, but you actually have to change directories and print the working directory to get the absolute full path.
Shows the size of the directory the command is ran in.
The size is in MB and GB.
There is no need to type the path, its the current working directory.
This will copy a file from your current directory to the same location on another machine. Handy for configuring ha, copying your resolv.conf, .bashrc, anything in /usr/local, etc.
Put the function in your .bashrc and use "map [alias]" to create the alias you want. Just be careful to not override an existing alias.
I submitted a command like this without $0 if $BASH_SOURCE is unset. Therefor, it did only work when using ./script, not using 'sh script'. This version handles both, and will set $mydir in a script to the current working directory. It also works on linux, osx and probably bsd.
This is freaking sweet!!! Here is the full alias, (I didn't want to cause display problems on commandlinefu.com's homepage):
alias tarred='( ( D=`builtin pwd`; F=$(date +$HOME/`sed "s,[/ ],#,g" <<< ${D/${HOME}/}`#-%F.tgz); S=$SECONDS; tar --ignore-failed-read --transform "s,^${D%/*},`date +${D%/*}.%F`,S" -czPf "$"F "$D" && logger -s "Tarred $D to $F in $(($SECONDS-$S)) seconds" ) & )'
Creates a .tgz archive of whatever directory it is run from, in the background, detached from current shell so if you logout it will still complete. Also, you can run this as many times as you want, if the archive .tgz already exists, it just moves it to a numbered backup '--backup=numbered'. The coolest part of this is the transformation performed by tar and sed so that the archive file names are automatically created, and when you extract the archive file it is completely safe thanks to the transform command.
If you archive lets say /home/tombdigger/new-stuff-to-backup/ it will create the archive /home/#home#tombdigger#new-stuff-to-backup#-2010-11-18.tgz Then when you extract it, like tar -xvzf #home#tombdigger#new-stuff-to-backup#-2010-11-18.tgz instead of overwriting an existing /home/tombdigger/new-stuff-to-backup/ directory, it will extract to /home/tombdigger/new-stuff-to-backup.2010-11-18/
Basically, the tar archive filename is the PWD with all '/' replaced with '#', and the date is appended to the name so that multiple archives are easily managed. This example saves all archives to your $HOME/archive-name.tgz, but I have a $BKDIR variable with my backup location for each shell user, so I just replaced HOME with BKDIR in the alias.
So when I ran this in /opt/askapache/SOURCE/lockfile-progs-0.1.11/ the archive was created at /askapache-bk/#opt#askapache#SOURCE#lockfile-progs-0.1.11#-2010-11-18.tgz
Upon completion, uses the universal logger tool to output its completion to syslog and stderr (printed to your terminal), just remove that part if you don't want it, or just remove the '-s ' option from logger to keep the logs only in syslog and not on your terminal.
Here's how my syslog server recorded this..
2010-11-18T00:44:13-05:00 gravedigger.askapache.com (127.0.0.5) [user] [notice] (logger:) Tarred /opt/askapache/SOURCE/lockfile-progs-0.1.11 to /askapache-bk/tarred/#opt#SOURCE#lockfile-progs-0.1.11#-2010-11-18.tgz in 4 seconds
Caveats
Really this is very robust and foolproof, the only issues I ever have with it (I've been using this for years on my web servers) is if you run it in a directory and then a file changes in that directory, you get a warning message and your archive might have a problem for the changed file. This happens when running this in a logs directory, a temp dir, etc.. That's the only issue I've ever had, really nothing more than a heads up.
Advanced:
This is a simple alias, and very useful as it works on basically every linux box with semi-current tar and GNU coreutils, bash, and sed.. But if you want to customize it or pass parameters (like a dir to backup instead of pwd), check out this function I use.. this is what I created the alias from BTW, replacing my aa_status function with logger, and adding $SECONDS runtime instead of using tar's --totals
function tarred ()
{
local GZIP='--fast' PWD=${1:-`pwd`} F=$(date +${BKDIR}/%m-%d-%g-%H%M-`sed -u 's/[\/\ ]/#/g'
[[ ! -r "$PWD" ]] && echo "Bad permissions for $PWD" 1>&2 && return 2;
( ( tar --totals --ignore-failed-read --transform "[email protected]^${PWD%/*}@`date +${PWD%/*}.%m-%d-%g`@S" -czPf $F $PWD && aa_status "Completed Tarp of $PWD to $F" ) & )
}
#From my .bash_profile http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
I love this function because it tells me everything I want to know about files, more than stat, more than ls. It's very useful and infinitely expandable.
find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n' | sort -rgbS 50%
00761 drwxrw---x askapache:askapache 777:666 [06/10/10 | 06/10/10 | 06/10/10] [d] /web/cg/tmp
The key is:
# -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'
which believe it or not took me hundreds of tweaking before I was happy with the output.
You can easily use this within a function to do whatever you want.. This simple function works recursively if you call it with -r as an argument, and sorts by file permissions.
lsl(){ O="-maxdepth 1";sed -n '/-r/!Q1'<<<[email protected] &&O=;find $PWD $O -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'|sort -rgbS 50%; }
Personally I'm using this function because:
lll () { local a KS="1 -r -g"; sed -n '/-sort=/!Q1' <<< [email protected] && KS=`sed 's/.*-sort=\(.*\)/\1/g'<<<[email protected]`;
find $PWD -maxdepth 1 -printf '%.5m %10M %#9u:%-9g %#5U:%-5G [%AD | %TD | %CD] [%Y] %p\n'|sort -k$KS -bS 50%; }
# i can sort by user
lll -sort=3
# or sort by group reversed
lll -sort=4 -r
# and sort by modification time
lll -sort=6
If anyone wants to help me make this function handle multiple dirs/files like ls, go for it and I would appreciate it.. Something very minimal would be awesome.. maybe like:
for a; do lll $a; done
Note this uses the latest version of GNU find built from source, easy to build from gnu ftp tarball. Taken from my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html
Another way of doing it that's a bit clearer. I'm a fan of readable code.