This shell snippet reads a single keypress from stdin and stores it in the $KEY variable.

You do NOT have to press the enter key!

The key is NOT echoed to stdout!

This is useful for implementing simple text menus in scripts and similar things.

This command use vnc to connect to another computer and emulate an dual-screen enviroment.

Example of use:

After this, if vnc server needs an password, will be prompt in the shell.

p.s.: sorry my english

Possible use, to filter something in stderr:

(/usr/bin/$COMMAND $PARAM 3>&1 1>&2 2>&3 | grep -v $uninteresting_error ) 3>&1 1>&2 2>&3

ncdu is a text-mode ncurses-based disk usage analyzer. Useful for when you want to see where all your space is going. For a single flat directory it isn't more elaborate than an du|sort or some such thing, but this analyzes all directories below the one you specify so space consumed by files inside subdirectories is taken into account. This way you get the full picture. Features: file deletion, file size or size on disk and refresh as contents change. Homepage: http://dev.yorhel.nl/ncdu

^Hexadecimal Ten minus Octal Ten is Eight(in Decimal).

^Hexadecimal AF and Octal 257 are both Decimal 175.

Here the pattern is '*.jar', you could pass in any pattern.

Another, maybe nicer way to do this is

http://www.commandlinefu.com/commands/view/1921/summarise-the-size-of-all-files-matching-a-simple-regex

You could replace sed with tr

w3m is a commanline web browser, full of options, I used -dump_head for less unnecessary page download.

With awk, I can retrieve dynamic changes in webpages in this very econnomical fashion

Uses htmldoc to perform the conversion

evento.sh needed for awk syntax

the aplay command makes a camera sound. It takes a picture of who looked at the display

#!/bin/bash

# evento.sh: deteta evento e fala

awk '{print}' | espeak -v pt -stdin

awk '/e/{print "emergencia"}' | espeak -v pt -stdin

aplay -q /home/mm/bash/camera.wav # -q inibe verbose do comand aplay

exit 0

Speaks whatever comes in via stdin (-v pt = portuguese, default = englisg)

..speech part of keyboard event talker. Made to accomplish a simple alarm central based on a cheap keyboard circuit. This way I have one zone per direct keypress. Depends on keypress.sh. It speaks out loud wich zone (key) has been pressed ( faulted ). Here is keypress.sh :

#!/bin/bash

# keypress.sh: Detect a user keypress ("hot keys").

echo

old_tty_settings=$(stty -g) # Save old settings (why?).

stty -icanon

Keypress=$(head -c1) # or $(dd bs=1 count=1 2> /dev/null)

# on non-GNU systems

aplay -q /home/mm/bash/beep-1.wav

echo

echo "Chamada quarto \""$Keypress"\"."

echo

stty "$old_tty_settings" # Restore old settings.

# Thanks, Stephane Chazelas.

exit 0

What do you do when nmap is not available and you want to see the hosts responding to an icmp echo request ? This one-liner will print all hosts responding with their ipv4 address.

Sort ls output of all files in current directory in ascending order

Just the 20 biggest ones:

A variant for the current directory tree with subdirectories and pretty columns is:

And finding the subdirectories consuming the most space with displayed block size 1k:

If you don't want your computer to try to boot form a USB stick that used to be used as a boot device (maybe for a live linux distro), you will have to remove the boot loader from your stick other wise the boot will fail each time the device is attached to your PC.

this takes every jpg in the current directory and changes the exif data for manufactur and model. in my case i change it to LOMO LC-A because my scanner puts his data in there :]

"find . -type d -print0 | xargs -0 chmod 755"

thanks masterofdisaster

This one-liner will the *delete* without any further confirmation all 100% duplicates but one based on their md5 hash in the current directory tree (i.e including files in its subdirectories).

Good for cleaning up collections of mp3 files or pictures of your dog|cat|kids|wife being present in gazillion incarnations on hd.

md5sum can be substituted with sha1sum without problems.

The actual filename is not taken into account-just the hash is used.

Whatever sort thinks is the first filename is kept.

It is assumed that the filename does not contain 0x00.

As per the good suggestion in the first comment, this one does a hard link instead:

If you don't want to delete them, but just want to list them, do

If you want to delete them with confirmation first, do

Using the -L flag follows symlinks, so the -type l test only returns true if the link can't be followed, or is a symlink to another broken symlink.

The URL can then be pasted with a middle click.

This is probably useful when trying to explain problems over instant messaging when you don't have some sort of shared desktop.

If your firewall or proxy at your location prevents connection to a particular host or port, you can use ssh to tunnel to your home server and do it there instead.

Uses ssh as tunnel tunnel for an other connection.

-f runs ssh in the background -N tell that there is no command to run -L deals with the forwarding aspect where the first number is the local port number, the second is parameter is the name of the server to forward to and the third parameter is the port number on that server. The last part of the command is the usual ssh form consisting of the user name and remote server name

Grab X11 input and create an MPEG at 25 fps with the resolution 800x600

more information: man sdiff