Commands tagged bash

If the return code from the last command was greater than zero, colour part of your prompt red. The commands give a prompt like this:

[user current_directory]$

After an error, the "[user" part is automatically coloured red.

Tested using bash on xterm and terminal. Place in your .bashrc or .bash_profile.

KISS

To get a random xkcd comic:

This function displays the latest comic from xkcd.com. One of the best things about xkcd is the title text when you hover over the comic, so this function also displays that after you close the comic.

To get a random xkcd comic use the following:

These are just a bit shorter than the ones eigthmillion wrote, however his version didn't work as expected on my laptop for some reason (I got the title-tag first), so these build a command which is executed by bash.

Shorter version with curl and awk

Output the html from xkcd's index.html, filter out the html tags, and then view it in gwenview.

Uses vi style search / replace in bash to rename files. Works with regex's too (I use the following a script to fixup / shorten file names):

# Remove complete parenthetical/bracket/brace phrases

rename 's/\(.*\)//g' *

rename 's/\[.*\]//g' *

rename 's/\{.*\}//g' *

rename is a great command, but can't get it to work on mac.

This is similar to using `!!` or

In bash 4.1 it seems you can bind directly to a shell command, but I'm not running that version.

Another alternative is to define a function:

lower() {

echo ${@,,}

}

lower StrinG

This is a command template for achiving the following:

* loop over files --> find -name "" | while read file; do ...; done

* output progress --> echo -n .

* execute some command on each file and save output for later usage --> output=$()

* if command failed, open subshell and echo newline --> || (echo;...;...;)

* echo output of command --> echo "$output"

Problem arises when ebuild gets removed from portage and you end up with old and unmaintained package that you cannot find standard way. This oneliner will give you list of those packages.

i have a large video file, 500+ MB, so i cant upload it to flickr, so to reduce the size i split it into 2 files. the command shows the splitting for the first file, from 0-4 minutes. ss is start time and t is duration (how long you want the output file to be).

credit goes to philc: http://ubuntuforums.org/showthread.php?t=480343

NOTE: when i made the second half of the video, i got a *lot* of lines like this:

frame= 0 fps= 0 q=0.0 size= 0kB time=10000000000.00 bitrate= 0.0kbit

just be patient, it is working =)

You have a script where =ALL= STDERR should be redirected to STDIN and you don't want to add "2>&1" at the end of each command...

E.G.:

Than just add this piece of code at the beginning of your script!

I hope this can help someone. :)

This command will download $file via server. I've used this when FTP was broken at the office and I needed to download some software packages.

It works best as part of a function, such as the following:

MUSICROOT=~/Music

function fplay {

if [ $1 = '-v' ]; then

shift 1

find -E $MUSICROOT -type f -iname "*$**" -iregex '.*\.(3g[2|p]|aac|ac3|adts|aif[c|f]?|amr|and|au|caf|m4[a|r|v]|mp[1-4|a]|mpeg[0,9]?|sd2|wav)' -print -exec afplay "{}" \; &

else

find -E $MUSICROOT -type f -iname "*$**" -iregex '.*\.(3g[2|p]|aac|ac3|adts|aif[c|f]?|amr|and|au|caf|m4[a|r|v]|mp[1-4|a]|mpeg[0,9]?|sd2|wav)' -exec afplay "{}" \; &

fi

}

Use this if you're using vi editing mode.

Example use :

##ah! that's the name of the file!

Example use :

##uh... autocomplete doesn't work...

##ah! that's the name of the file!

I like the other three versions but one uses nested loops and another prints every color on a separate line. Both versions fail to reset colors before giving the prompt back.

This version uses the column command to print a table so all the colors fit on one screen. It also resets colors back to normal before as a last step.

If a tmux session is already running attach it, otherwise create a new one. Useful if you often forget about running tmuxes (or just don't care)

forces user to rw, group to r, and other to no access.

files will not be marked executable.

directories will be executable for users and groups only.

I used to do a lot of path manipulation to set up my development environment (PATH, LD_LIBRARY_PATH, etc), and one part of my environment wasn't always aware of what the rest of the environment needed in the path. Thus resetting the entire PATH variable wasn't an option; modifying it made sense.

The original version of the functions used sed, which turned out to be really slow when called many times from my bashrc, and it could take up to 10 seconds to login. Switching to parameter substitution sped things up significantly.

The commands here don't clean up the path when they are done (so e.g. the path gets cluttered with colons). But the code is easy to read for a one-liner.

The full function looks like this:

I tried using regexes to make this into a cleaner one-liner, but remove_path ended up being cryptic and not working as well: