Commands using echo

above line in .bash_profile will give you window title in putty or terminal client when you login to your remote server

The $[...] block in bash and zsh will let you do math.

This is the same as using $((...)), which also works in ksh. Of course, this is a simple, dumb wrapper and doesn't allow floating-point.

Countdown from 10 or whatever you want:)

unsets variables used by the one-liner

sets up the IFS bash variable to not be affected by whitespace and disables extra glob expansion

uses read to slurp the results of the find command into an array

selects an element of the array at random to be passed as an argument to mplayer

This is the solution to the common mistake made by sudo newbies, since

does NOT add to the file as root.

Alternatively,

should be replaced by

And you can add a >/dev/null in the end if you're not interested in the tee stdout :

If you are using an xterm emulation capable terminal emulator, such as PuTTY or xterm on Linux desktop, this command will replace the title of that terminal window. I know it is not nice to have seventeen terminals on your desktop with title PuTTY, you can not tell which one is connected to which server and doing what.

Even though the string between the quotes is typed as literals, it needs a little more finesse to make it work. Here is how it is done key-by-key:

echo "( ctrl-v then ctrl-[ )0;Enter_Title_String_Here( ctrl-v then ctrl-g )"( enter )

ctrl-v : means hold down ctrl key and hit v at the same time like you are pasting in windoze ; also please don't type the parentheses, i.e., ( and )

When expanding, bash output the command, so don't be affraid if you type the command.

Here is the details:

First examples:

First argument:

echo barfoo

barfoo

(Note that typing echo foo bar foobar barfoo && echo !$, bash substitute !$ with $:1)

Last argument:

echo foo bar foobar barfoo && echo barfoo

foo bar foobar barfoo

barfoo

All the arguments:

echo foo bar foobar barfoo

foo bar foobar barfoo

The third argument:

echo foo bar foobar barfoo && echo foobar

foo bar foobar barfoo

foobar

You may want to add {} for large numbers: echo !:{11} for example

Now with path:

/usr/bin/foobar

For the head:

echo /usr/bin

/usr/bin

And the tail:

echo foobar

foobar

You also may want to try !:h and !:t or !!3-4 for the third and the fourth (so !!:* == !!:1-$)

seq allows you to format the output thanks to the -f option. This is very useful if you want to rename your files to the same format in order to be able to easily sort for example:

And

foo1

foo10

foo4

foo7

But:

So

foo01

foo04

foo07

foo10

This commands lets you generate a random number between the range [$START; $END].

I know its not much but is very useful in time consuming scripts (cron, rc.d, etc).

show phpinfo(); from the command line

This command converts a MySQL query directly into a .csv (Comma Seperated Value)-file.

Replace sed regular expressions with perl patterns on the command line.

The sed equivalent is: echo "sed -e"|sed -e 's/sed -e/perl -pe/'

Modify the script for your username and password, and save it as a script. Run the script, and enjoy ./tweet

Print 0 through 99, each on a separate line.

This works in bash and zsh.

You may also want to alias it, if you need to look at it often...

"\$PATH" to make sure to look at your current $PATH

this is very useful when there is a different network host to determine which are turned on or not

Return the current shell. It is better than print $SHELL which can sometimes return a false value.