Simple function to permanently add an alias to your profile.

Tested on bash and Ksh, bash version above.

Here is the ksh version: PERMA () { print "$@" >> ~/.profile; }

Sample usage:

PERMA alias la='ls -a'

I like the fact the Patola's version uses only ones and zeros, but I also like the sparse output of the other versions. This one combines both of those features and eliminates some unnecessary cruft.

You can vary the sparseness by changing "$(($RANDOM % 5))" to another number. The number in this term "$(($RANDOM % 4))" controls how frequently the numbers are output bold.

This command will disable the beep sound from the PC speaker.

After this, just type:

You need to install "beep" before this would make the beep sound.

Save it in your .profile if you want to use it later

WARNING: this command won't exit until it is successful. You won't be able to CONTROL+C out of it.

If the connection works you should see a "hello" on host A. If not: check your cabeling etc :-)

You're behind on your TV catch-up, but how far behind? This command tries to open mplayer against all files in the current dir. If it's a video file it will contain ID_LENGTH, which is summed and output in hours, minutes and seconds.

Someone better at awk could probably reduce this down a lot.

I never can remember the syntax of awk. You can give a different -d option to cut to separate by e.g. commas. Also this allows to do more things with the generated SQL, e.g. to redirect it into different files.

Grab the RSS link to the Picasa album. Feed it to the script when its hungry. When its done writing the shopping list, just use

to get your stuff.

if "mail -a" fail, try "mutt -a" or "nail -a"

Very useful in shell scripts because you can run a task nicely in the background using job-control and output progress until it completes.

Here's an example of how I use it in backup scripts to run gpg in the background to encrypt an archive file (which I create in this same way). $! is the process ID of the last run command, which is saved here as the variable PI, then sleeper is called with the process id of the gpg task (PI), and sleeper is also specified to output : instead of the default . every 3 seconds instead of the default 1. So a shorter version would be sleeper $!;

The wait is also used here, though it may not be needed on your system.

Previously to get around the $! not always being available, I would instead check for the existance of the process ID by checking if the directory /proc/$PID existed, but not everyone uses proc anymore. That version is currently the one at http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html but I plan on upgrading to this new version soon.

This will log your internet download speed.

You can run

to get a graph of it.

I often need to know of my directory in the PATH, which one DOES NOT exist. This command answers that question

* This command uses only bash's built-in commands

* The parentheses spawn a new sub shell to prevent the modification of the IFS (input field separator) variable in the current shell

I usually have 5 or more ssh connections to various servers, and putting this command in my .bash_profile file makes my putty window or x terminal window title change to this easily recognizable and descriptive text. Includes the username, group, server hostname, where I am connecting from (for SSH tunneling), which device pts, current server load, and how many processes are running.

You can also use this for your PROMPT_COMMAND variable, which updates the window title to the current values each time you exec a command.

I prefix running this in my .bash_profile with

which makes sure it only does this when connecting via SSH with a TTY.

Here's some rougher examples from http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

And here's a simple function example for setting the title:

Finds executable and existing directories in your path that can be useful if migrating a profile script to another system. This is faster and smaller than any other method due to using only bash builtin commands.

See also:

+ http://www.commandlinefu.com/commands/view/743/list-all-execs-in-path-usefull-for-grepping-the-resulting-list

+ http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Uses 'seq' with formatting parameter to generate the necessary padded sequence. Change '%02.0f' to how many digits you need (for 3, use %03.0f, etc) and replace 5 & 15 with your desired min and max.

This is just for fun.

Bash 4 will let you do {00..19} to get leading zeros, but Bash 3 doesn't have that feature. This technique gets you partway there (the sequences need be such that the last digit ranges from zero to nine - you can't use this for something like Bash 4's {03..27}, for example). When this limitation is not a problem, you can avoid some complicated string manipulation for concatenating leading zeros.

You can add more digits like this: {0..1}{0..9}{0..9} (ranges from 0 to 99 with up to two leading zeros). To pad with additional zeros:

or

This is useful for creating values to sort or for creating filenames with a fixed format. Note that this will also work:

Handles everything except octets with 255. Ran through ip generator with variable octet lengths.

This obey that you don't match any broadcast or network addresses and stay between 1.1.1.1 - 254.254.254.254

regex to match an ip

This command dumps all SVN repositories inside of folder "repMainPath" (not recursively) to the folder "dumpPath", where one dump file will be created for each SVN repository.