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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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.
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,…):
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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:
If you put this in your .bashrc, you might also want to add this to make it use the colors by default:
alias ls="ls --color=auto"
This is useful for piping to other commands, as well:
svn status | egrep '^(M|A)' | egrep -o '[^MA\ ].*$' | xargs $EDITOR
I got really tired of having tree always show me tons of .svn and .git stuff that I don't care about. With this alias, "tree" uses pretty colors, snazzy line graphics, and ignores any source control and package mumbojumbo. (Customize the *.*.package glob, of course.)
Good old cat & output redirection. Using this method you can combine all kinds of things - even mpeg files. My video camera makes a series of .mpeg files that are broken into 4gb chunks. Using this command I can easily join them together. Even better, combined with the cp command the files can be copied and joined in one step.
I wrote a script called bootstrap.py to delete the database, then load a new database with initial values. With this single-line shell loop, when I need to make a schema change (which happens often in the early stages of some projects), I hit ctrl-C to stop the running Django server, then watch bootstrap.py do its thing, then watch the server restart.
This is useful if you have a collection of files in folders (for example, a bunch of .zip files that are contained in folders) and you want to move them all to a common folder.
Assuming you are working within a git repository, you can run the above command & see what has changed in reverse chronological order, with one commit per line. Other formatting variations to 'oneline' include 'short', 'medium', 'full', 'fuller', 'email' or 'raw'.
Seems obvious, but other seemingly simple ways to use it don't work:
-bash: !whammy: event not found
with the slash :(
you can also do any combinations of quotes for a complex string:
echo "It's great to be able to use a bang ("'!'") in a command"'!'
It's great to be able to use a bang (!) in a command!
I love CiteULike. It makes keeping a bibtex library easy and keeps all my papers in one place. However, it can be a pain when I add new entries and have to go through the procedure for downloading the new version in my browser, so I made this to grab it for me! I actually pipe it directly into a couple of SED one liners to tidy it up a bit too. Extremely useful, especially if you make a custom BibTeX script that does this first. That way you can sort a fresh BibTeX file for each new paper with no faf.
To use just replace with your CiteULike user name. It doesn't download entries that you've hidden but I don't use that feature anyway.
Use Ctrl-] to stop it.
The idea was originally stolen from Linux Journal. 'wget' pulls the debt clock and 'sed' reformats it for general consumption. Prefacing the command with 'watch' simply sets an interval - in this case every 10 seconds.
See man vmstat for information about the statistics.
This does the same thing without the timestamp:
This truncates any lines longer than 80 characters. Also useful for looking at different parts of the line, e.g. cut -b 50-100 shows columns 50 through 100.
Can be used for other commands as well, replace rm with ls.
It is easy to make this shorter but if the filenames involved have spaces, you will need to do use find's "-print0" option in conjunction with xargs's "-0" option. Otherwise the shell that xargs uses to execute the "rm" command line will treat the space as a token separator, thereby treating the name as two (or more) names.
say you want to reinitialize the slave database without resetting the master positions. You stop the slave, dump the master database with --master-data=2 then execute the command on the slave and wait for it to stop at the exact position of the dump. reinit the slave db and start the slave. enjoy.
Here $HOME/shots must exist and have appropriate access rights and sitecopy must be correctly set up to upload new screen shots to the remote site.
Example .sitecopyrc (for illustration purposes only)
The command uses scrot to create a screen shot, moves it to the screen shot directory, uploads it using screen uses xsel to copy the URL to the paste buffer (so that you can paste it with a middle click) and finally uses feh to display a preview of the screen shot.
Note that $BASE stands for the base URL for the screen shots on the remote server, replace it by the actual location; in the example http://www.example.com/~user/shots would be fitting.
Assign this command to a key combination or an icon in whatever panel you use.
A web server using $HOME/public_html as user directory is required, $HOME/public_html/shots must exist and have appropriate access rights and $HOSTNAME must be known to and accessible from the outside world.
The command uses scrot to create a screen shot, moves it to the screen shot directory, uses xsel to copy the URL to the paste buffer (so that you can paste it with a middle click) and finally uses feh to display a preview of the screen shot.
Assign this command to a key combination or an icon in whatever panel you use.
Generate the iso from the disk, easily.
same as "dd if=/dev/cdrom of=~/mydisk.iso"
"unzip *.zip" doesn't work as expected, because unzip handle wildcards in a different way.
You just need to escape the wildcard or do in another way:
for f in *.zip; do unzip "$f"; done
xclip -o > /tmp/spell.tmp # Copy clipboard contents to a temp file
aspell check /tmp/spell.tmp # Run aspell on that file
cat /tmp/spell.tmp | xclip # Copy the results back to the clipboard, so that you can paste the corrected text
I'm not sure xclip is installed in most distributions. If not, you can install x11-apps package
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:
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:
# default screenrc on any host
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 -t 'anywhere' /bin/tcsh
screen -t 'anywhere1' /bin/tcsh
The .screenrc-base contains:
## I find typing ^a (Control-a) awkward. So I set the escape key to CTRL-j instead of a.
termcapinfo xterm* ti@:te@: