Commands tagged bash

Based on the MrMerry one, just add some visuals and sort directory and files

checkfor: have the shell check anything you're waiting for.

'while : ; do' is an infinite loop

'$*' executes the command passed in

'sleep 5' - change for your tastes, sleep for 5 seconds

bash, ksh, likely sh, maybe zsh

Ctrl-c to break the loop

fcd : file change directory

A bash function that takes a fully qualified file path and cd's into the directory where it lives. Useful on the commadline when you have a file name in a variable and you'd like to cd to the directory to RCS check it in or look at other files associated with it.

Will run on any ksh, bash, likely sh, maybe zsh.

Shorter version.

This is what I use to collect man pages before I print them out. There are other ones that have been submitted, so I just wanted to give out another. Requires cups-pdf to be installed.

If you need to ssh into a computer on the local network but you're unsure of the ip to use, then ping them and see if you get a response. If you do, print out the address you got it from. Adjust the range to suit your network.

"&&" runs sed if and only if the backup completed and /bin/cp exited cleanly. Works for multiple files; just specify multiple filenames (or glob). Use -v switch for cp to play it safe.

The coolest way I've found to backup a wordpress mysql database using encryption, and using local variables created directly from the wp-config.php file so that you don't have to type them- which would allow someone sniffing your terminal or viewing your shell history to see your info.

I use a variation of this for my servers that have hundreds of wordpress installs and databases by using a find command for the wp-config.php file and passing that through xargs to my function.

Best to put it in a file somewhere in your path. (I call the file spath)

#!/bin/bash

IFS=:; find $PATH | grep $1

Usage: $ spath php

The original doesn't work for me - but this does. I'm guessing that Youtube updated the video page so the original doesn't work.

( IFS=:; for i in $PATH; do echo $i; done; )

echo $PATH|sed -e 's/:/\n/g' # but the tr one is even better of course

echo $PATH|xargs -d: -i echo {} # but this comes up with an extra blank line; can't figure out why and don't have the time :(

echo $PATH|cut -d: --output-delimiter='

' -f1-99 # note -- you have to hit ENTER after the first QUOTE, then type the second one. Sneaky, huh?

echo $PATH | perl -l -0x3a -pe 1 # same darn extra new line; again no time to investigate

echo $PATH|perl -pe 's/:/\n/g' # too obvious; clearly I'm running out of ideas :-)

This command allows you to see a preview of a picture via the terminal. It can be usefull when you are ssh'ing your server without X-forwarding.

To have en example of the output you can get with this command see http://www.vimeo.com/3721117

Download at http://inouire.net/image-couleur.html

Sources here: http://inouire.net/archives/image-couleur_source.tar.gz

In Bash, when defining an alias, one usually loses the completion related to the function used in that alias (that completion is usually defined in /etc/bash_completion using the complete builtin).

It's easy to reuse the work done for that completion in order to have smart completion for our alias.

That's what is done by this command line (that's only an example but it may be very easy to reuse).

Note 1 : You can use given command line in a loop "for old in apt-get apt-cache" if you want to define aliases like that for many commands.

Note 2 : You can put the output of the command directly in your .bashrc file (after the ". /etc/bash_completion") to always have the alias and its completion

Uses the last argument of the last executed command, and gets the directory name from it.

Use $!:t for the filename alone, without the dirname.

I wanted all the 'hidden' .flv files from the http link in the command line; wget seemed appropriate, fed with output from lynx, grep the flv files and the normalised via sed (to remove the numeric bullet). Similar to the 'Grab mp3 files' fu. Replace link with your own, grep arg with something more interesting ;) See here for something along the same lines...

http://www.commandlinefu.com/commands/view/1006/grab-mp3-files-from-your-favorite-netcasts-mp3blog-or-sites-that-often-have-good-mp3s

Hope you find it useful! Improvements welcome, naturally.

Create a bunch of random files with random binary content. Basically dd dumps randomly from your hard disk to files random-file*.

Add this to your $HOME/.bashrc file. It will only set this prompt if it is running inside screen ($WINDOW var is set)

Looks like this...

a shorter version

This command finds the 5 (-n5) most frequently updated logs in /var/log, and then does a multifile tail follow of those log files.

Alternately, you can do this to follow a specific list of log files:

sudo tail -n0 -f /var/log/{messages,secure,cron,cups/error_log}

Create a single tar.gz archive

I know it's a very basic one, but it's one I keep forgetting.

To ensure that it will never come back, you can edit /etc/modprobe.d/blacklist

Add "blacklist pcspkr" sans quotes

Save the script as: sort_file

Usage: sort_file < sort_me.csv > out_file.csv

This script was originally posted by Admiral Beotch in LinuxQuestions.org on the Linux-Software forum.

I modified this script to make it more portable.