Commands tagged scripting (3)

  • Placing sudo in the shebang line of a shell script runs the entire thing as root. Useful for scripts designed to, e.g. automate system upgrades or package manager wrappers — makes prepending everything with sudo no longer necessary


    5
    #!/usr/bin/sudo /bin/bash
    realkstrawn93 · 2021-04-27 05:04:30 15
  • use it to add a random boolean switch to your script Show Sample Output


    4
    echo $[RANDOM % 2]
    anapsix · 2013-05-25 19:15:57 3
  • This function will encrypt a bash script and will only execute it after providing the passphrase. Requires mcrypt to be installed on the system. Show Sample Output


    1
    scrypt(){ [ -n "$1" ]&&{ echo '. <(echo "$(tail -n+2 $0|base64 -d|mcrypt -dq)"); exit;'>$1.scrypt;cat $1|mcrypt|base64 >>$1.scrypt;chmod +x $1.scrypt;};}
    rodolfoap · 2017-06-14 16:27:20 2

What's this?

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

Share Your Commands


Check These Out

Record MP3 audio via ALSA using ffmpeg
Record audio to an MP3 file via ALSA. Adjust -i argument according to arecord -l output.

use xxd to create the wake on lan magicpacket and write to pcap file
just set macdst to the mac address of the system you wish to wake up, the macsrc is optional but helps use tcpreplay to broadcast or wireshark to view

Compress blank lines in VIM
This command will squeeze all consequent blank lines (including those with only space and tab charactes) to one. It will also empty the resulting line (remove the "|s/.*//" part if you don't need that).

Determine what an process is actually doing

Clean up after a poorly-formed tar file
These days, most software distributed in tar files will just contain a directory at the top level, but some tar files don't have this and can leave you with a mess of files in the current folder if you blindly execute $ tar zxvf something.tar.gz This command can help you clean up after such a mistake. However, note that this has the potential to do bad things if someone has been *really* nasty with filenames.

random xkcd comic
i sorta stole this from http://www.shell-fu.org/lister.php?id=878#MTC_form but it didn't work, so here it is, fixed. --- updated to work with jpegs, and to use a fancy positive look behind assertion.

find the biggest file in current folder

Which processes are listening on a specific port (e.g. port 80)
swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

bash: display disks by id, UUID and HW path
Shows a tree of the disks. Requires "tree"

Adding formatting to an xml document for easier reading
Sometimes you're trying to read through an xml file to determine whats wrong with it and a tool had removed all the linebreaks. xmllint will go ahead and make it pretty for you.


Stay in the loop…

Follow the Tweets.

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

Subscribe to the feeds.

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: