Lists crontab for all users on system that have crontabs.

Very useful for interactive scripts where you would like to return the terminal contents to its original state before the script was run. This would be similar to how vi exits and returns you to your original terminal screen.

Save and clear the terminal contents with:

Execute some commands, then restore the saved terminal contents with:

This is how I list the crontab for all the users on a given system that actually have a crontab.

You could wrap it with a function block and place it in your .profile or .bashrc for quick access.

There's prolly a simpler way to do this. Discuss.

usage: sitepass MaStErPaSsWoRd example.com

description: An admittedly excessive amount of hashing, but this will give you a pretty secure password, It also eliminates repeated characters and deletes itself from your command history.

tr '!-~' 'P-~!-O' # this bit is rot47, kinda like rot13 but more nerdy

rev # this avoids the first few bytes of gzip payload, and the magic bytes.

Changing newline to spaces using just echo

Creates a consistent datapumpt export on an Oracle database with the current sequence number, while the system is running and changes happens on the database.

Mostly for Norwegians, but easily adoptable to others. Very handy if you are brainstorming for a new domainname.

Will only display the available ones..

You can usually do this better with dig, but if you dont have dig, or the TLD only have an online service to check with, this will be usefull..

this is helpful because dmesg is where i/o errors, etc are logged to... you will also be able to see when the system reboots or someone attaches a thumb drive, etc.

don't forget to set yourself up in /etc/aliases to get roots email.

A little bash daemon

Convert string to array using echo and sed =)

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.