Commands using set

The biggest advantage over atoponce's nifty original is not killing the scrollback. Written assuming bash, but shouldn't be terribly difficult to port to other shells. S should be multiple spaces, but I can't get commandlinefu to save/show them properly, any help?

Open a file directly with execution permission.

Put the function in your .bashrc

You can also put this in your vimrc:

and open a new file like this:

By default bash expands an unbound variable to an empty string. This can be dangerous, if a critical variable name (a path prefix for example) has a typo. The -u option causes bash to treat this as an error, and the -e option causes it to exit in case of an error. These two together will make your scripts a lot safer against typos.

The default behaviour can be explicitly requested using the ${NAME:-} syntax.

A (less explicit) variation: #!/bin/bash -eu

Turn shell tracing and verbosity (set -xv) on/off in any Bourne-type shell

If either -x or -v is set, the function turns them both off.

If neither is on, both are turned on.

Running this command turns shell tracing and shell verbose debugging on or off. Not only does it do that, it also uses your terminals builtin method of setting colors to make debugging much easier.

It looks at the current shell options contained in the $- special bash variable and that lets this function set the opposite of the current value. So from the shell you could do a:

and it will turn on debbuggin.

This is an amazingly useful function that is perfect to add system-wide by adding it to /etc/profile or /etc/bashrc.. You can run it from the shell, and you can also use it in your shell scripts like my .bash_profile - http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

Prompts the user for username and password, that are then exported to http_proxy for use by wget, yum etc

Default user, webproxy and port are used.

Using this script prevent the cleartext user and pass being in your bash_history and on-screen

the 'set -x' mode can be exited by typing

If you set noclobber to on, bash won't allow redirection to overwrite existing files .

You can still append information but not overwrite the file .to turn it back off use : $ set +o noclobber .

I use it because i overwrite a file by accident , after thought , content of the file was very important , creating a one more file mean nothing for my hard disk (we are not anymore on the 64 k memory time) , but content of file is far much important . What we call exeprience :(

Once issuing the command, hit "esc" and then "k" (not together) to enter the search mode at the shell prompt (each time), and invoke the search with "/" as if you would in vi. Type a command and see the most recently used instance of that command. Use "n" and "N" to go forward and backwards through other instances of that command.

If you issue the "set" command, you'll see a list of variables and functions. This command displays just those functions' names.

Volume up und unmute (ignored if Master is not muted).

Replace "+" by "-" for volume down and unmute if necessary.

This lets you use your favorite vi edit keys to navigate your term.

To set it permanently, put "set editing-mode vi" in your ~/.inputrc or /etc/inputrc.

Use set +o noclobber and you will be able to replace files again

this will increase the volume by 2 decibels on the pcm channel. the argument to -c is for which sound card to use, the arg after set is the channel (PCM, Master, etc.) and what to set by.

related commands:

amixer -c 0 set PCM 2dB-

decrease volume by 2 decibels

amixer -c 0 set PCM toggle

toggle mute/unmute

this is for alsa systems

for mac os (and maybe other UNIX systems) osascript -e 'set Volume *' where * is any number (can have decimal points) between 0 and 10

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

If you spend all day editing in vi then switching your fingers to Emacs mode just for the command line can be difficult. Use set -o vi in your bash shell and enjoy the power of a real editor.