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Periodically run a command without hangups, and send the output to your e-mail
Run "ps -x" (process status) in the background every hour (in this example). The outputs of both "nohup" and "ps -x" are sent to the e-mail (instead of nohup.out and stdout and stderr). If you like it, replace "ps -x" by the command of your choice, replace 3600 (1 hour) by the period of your choice. You can run the command in the loop any time by killing the sleep process. For example $ ps -x 2925 ? S 0:00.00 sh -c unzip E.zip >/dev/null 2>&1 11288 ? O 0:00.00 unzip E.zip 25428 ? I 0:00.00 sleep 3600 14346 pts/42- I 0:00.01 bash -c while true; do ps -x | mail (...); sleep 3600; done 643 pts/66 Ss 0:00.03 -bash 14124 pts/66 O+ 0:00.00 ps -x $ kill 25428 You have mail in /mail/(...)

gawk gets fixed width field

Console clock
Shows a simple clock in the console -t param removes the watch header Ctrl-c to exit

Two command output
Summarize established connections after netstat output. Using tee and /dev/stderr you can send one command output to terminal before executing wc so you can summarize at the bottom of the output.

check the status of 'dd' in progress

throttle bandwidth with cstream
this bzips a folder and transfers it over the network to "host" at 777k bit/s. cstream can do a lot more, have a look http://www.cons.org/cracauer/cstream.html#usage for example: $ echo w00t, i'm 733+ | cstream -b1 -t2 hehe :)

function to edit your history file
eh stands for Edit History . Frequently, I'll mistype a command, and then step back through my history and correct the command. As a result, both the correct and incorrect commands are in my history file. I wanted a simple way to remove the incorrect command so I don't run it by mistake. . When running this function, first the ~/bash_history file is updated, then you edit the file in vi, and then the saved history file is loaded back into memory for current usage. . while in vi, remember that `Shift-G` sends you to the bottom of the file, and `dd` removes a line. . this command is different than bash built-in `fc` because it does not run the command after editing.

True random passwords using your microphone noise as seed
Generate a truly random password using noise from your microphone to seed the RNG. This will spit out 12 password with 12 characters each, but you can save this into a bash script and replace 'pwgen -ys 12 12' with 'pwgen $@' so you can pass any paramters to pwgen as you would normally do.

Display or use a random file from current directory via a small bash one-liner
An other way to run it ( playing a random file ending with avi, flv or mpeg ) from a specified dir and a specified type of extension : making MOVIE array with a glob : $ MOVIE=( /PATH/TO/MY/FAVORITE/MOVIES/*.{avi,flv,mpeg} ) playing the random file from a random key from the array $ mplayer ${MOVIE[ RANDOM % ( ${#i[@]} + 1 ) ]]} I use only globs and a bash array. I use GNU bash, version 3.2.48

See how many more processes are allowed, awesome!
There is a limit to how many processes you can run at the same time for each user, especially with web hosts. If the maximum # of processes for your user is 200, then the following sets OPTIMUM_P to 100. $ OPTIMUM_P=$(( (`ulimit -u` - `find /proc -maxdepth 1 \( -user $USER -o -group $GROUPNAME \) -type d|wc -l`) / 2 )) This is very useful in scripts because this is such a fast low-resource-intensive (compared to ps, who, lsof, etc) way to determine how many processes are currently running for whichever user. The number of currently running processes is subtracted from the high limit setup for the account (see limits.conf, pam, initscript). An easy to understand example- this searches the current directory for shell scripts, and runs up to 100 'file' commands at the same time, greatly speeding up the command. $ find . -type f | xargs -P $OPTIMUM_P -iFNAME file FNAME | sed -n '/shell script text/p' I am using it in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html especially for the xargs command. Xargs has a -P option that lets you specify how many processes to run at the same time. For instance if you have 1000 urls in a text file and wanted to download all of them fast with curl, you could download 100 at a time (check ps output on a separate [pt]ty for proof) like this: $ cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}' I like to do things as fast as possible on my servers. I have several types of servers and hosting environments, some with very restrictive jail shells with 20processes limit, some with 200, some with 8000, so for the jailed shells my xargs -P10 would kill my shell or dump core. Using the above I can set the -P value dynamically, so xargs always works, like this. $ cat url-list.txt | xargs -I '{}' -P $OPTIMUM_P curl -O '{}' If you were building a process-killer (very common for cheap hosting) this would also be handy. Note that if you are only allowed 20 or so processes, you should just use -P1 with xargs.


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