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Replace strings in files

Replace the word 'war' to word 'peace' in every file in the current directory.
This is sample output - yours may be different.
0

sed -i -e 's/war/peace/g' *

tiagofischer · 2010-01-02 13:16:35 3
Shorten url using bit.ly API

It uses curl --url-encode to encode long URLs *properly* and parses XML with xmlstarlet. If ~/.bitlyrc were to contain login:apikey then a script could read the apiKey and login from ~/.bitlyrc like so: login=$(sed 's/:.*//' < $HOME/.bitlyrc) apikey=$(sed 's/[^:]*://' < $HOME/.bitlyrc) curl -s --data-urlencode 'longUrl='$1 --data-urlencode 'login='$login --data-urlencode 'apiKey='$apikey 'http://api.bit.ly/shorten?version=2.0.1&format=xml' | xmlstarlet sel -T -t -m "//shortUrl" -v "." | line Show Sample Output
This is sample output - yours may be different.
```
[16:58][~]$ bitly http://google.com
http://bit.ly/4sloPA
```
0

curl -s --data-urlencode 'longUrl='$1 --data-urlencode 'login='$login --data-urlencode 'apiKey='$apikey 'http://api.bit.ly/shorten?version=2.0.1&format=xml' | xmlstarlet sel -T -t -m "//shortUrl" -v "." | line

jnash · 2010-01-02 11:32:42 3
cd up a number of levels

Instead of typing "cd ../../.." you can type ".. 3". For extremely lazy typists, you can add this alias: alias ...=".. 2" ....=".. 3" - so now you can write just .... !!! NB the .. function needs to be "source"d or included in your startup scripts, perhaps .bashrc.
This is sample output - yours may be different.
4

function ..(){ for ((j=${1:-1},i=0;i<j;i++));do builtin cd ..;done;}

bhepple · 2010-01-02 08:36:12 12
convert wav into mp3 using lame
This is sample output - yours may be different.
1

lame -V2 rec01.wav rec01.mp3

eastwind · 2010-01-01 06:09:46 4
Chage default shell for all users [FreeBSD]

This command will set bash as the default shell for all users in a FreeBSD system.
This is sample output - yours may be different.
6

cd /usr/home && for i in *;do chsh -s bash $i;done

casidiablo · 2009-12-31 18:48:53 6
pipe output to notify-send

Route output to notify-send to show nice messages on the desktop, e.g. title and interpreter of the current radio stream
This is sample output - yours may be different.
2

echo 'Desktop SPAM!!!' | while read SPAM_OUT; do notify-send "$SPAM_OUT"; done

michelsberg · 2009-12-31 15:38:35 3
Display _something_ when an X app fails

When you run an X program from a terminal you can see any errors. But when it's run from another X program (eg from a menu item, from your fluxbox 'keys' file etc) it might just die and you see nothing (except perhaps in .xsession-errors). Instead, launch it via this command and you'll see the termination status, stderr and stdout. eg: "xlaunch firefox" or "xlaunch 'echo stdout; echo stderr >&2; false'": 'echo stdout; echo stderr >&2; false' failed with error 1 STDERR: stderr STDOUT: stdout
This is sample output - yours may be different.
1

xlaunch(){ T=/tmp/$$;sh -c "$@" >$T.1 2>$T.2;S=$?;[ $S -ne 0 ]&&{ echo -e "'$@' failed with error $S\nSTDERR:\n$(cat $T.2)\nSTDOUT:\n$(cat $T.1)\n"|xmessage -file -;};rm -f $T.1 $T.2;}

bhepple · 2009-12-31 06:59:56 3
Setup a persistant SSH tunnel w/ pre-shared key authentication

This creates a persistent ssh -i /path/to/key -ND local-IP:PORT User@Server connection. You may have to install autossh. -f puts in daemon mode. if you are having trouble, try it without -f.
This is sample output - yours may be different.
4

autossh -f -i /path/to/key -ND local-IP:PORT User@Server

fotoflo · 2009-12-31 06:10:03 5
external projector for presentations

i spent way too many hours trying to fiddle with /etc/X11/xorg.conf trying to hook up various external projectors. too bad i didn't know this would solve all my problems.
This is sample output - yours may be different.
8

xrandr --auto

kanzure · 2009-12-30 18:52:02 9
mount an iso

mounts an ISO file to a directory on the target file system
This is sample output - yours may be different.
6

mount -o loop -t iso9660 my.iso /mnt/something

kanzure · 2009-12-30 18:49:30 4
climagic's New Year's Countdown clock

This is the 140 character long new year's countdown timer that was posted to the climagic account on twitter and identi.ca. There are saner ways of doing this of course, but probably none of those would fit. Uses the figlet command, but of course you can replace figlet with just echo if you want. Show Sample Output
This is sample output - yours may be different.
```
 _ ____  _____ ___   ___   __
/ |___ \|___ // _ \ ( _ ) / /_
| | __) | |_ \ (_) |/ _ \| '_ \
| |/ __/ ___) \__, | (_) | (_) |
|_|_____|____/  /_/ \___/ \___/
```
6

while V=$((`date +%s -d"2010-01-01"`-`date +%s`));do if [ $V == 0 ];then figlet 'Happy New Year!';break;else figlet $V;sleep 1;clear;fi;done

deltaray · 2009-12-30 18:42:38 11
Increase mplayer maximum volume

use '0' and '9' to increase/decrease volume. this is useful on laptops with low speaker volume.
This is sample output - yours may be different.
7

mplayer dvd:// -softvol -softvol-max 500

kanzure · 2009-12-30 18:19:44 9
Find and print pattern location from all files on command line from directory and its sub directories.

The command will help to print the location of the pattern. Above command will print all the files which contain variable "$foo" along with line containing that pattern. Specify pattern after "grep"
This is sample output - yours may be different.
-1

find . -exec grep $foo {} \; -print

linuxgeek · 2009-12-30 17:41:44 4
monitor network traffic and throughput in real time

see http://iptraf.seul.org/ for all kinds of documentation and screenshots
This is sample output - yours may be different.
4

iptraf

linuxrawkstar · 2009-12-30 15:41:21 4
Get your public ip

Requires Python; doesn't require a specific server to return your IP.
This is sample output - yours may be different.
-11

python -c "import socket; s=socket.socket(socket.AF_INET, socket.SOCK_DGRAM); s.connect(('google.com', 80)); print s.getsockname()[0]"

whiteinge · 2009-12-29 19:17:03 10
generate random password

eliminates "l" and "o" characters change length by changing 'x' here: cut -c 1-x Show Sample Output
This is sample output - yours may be different.
```
d6pd9625
```
-3

openssl rand -base64 1000 | tr "[:upper:]" "[:lower:]" | tr -cd "[:alnum:]" | tr -d "lo" | cut -c 1-8 | pbcopy

_eirik · 2009-12-29 17:18:25 31
Display the output of a command from the first line until the first instance of a regular expression.

Slightly simpler version of previous sed command that does the same thing. In this case, the output will stop at the command, and the entire command will be terminated as well, instead of proceeding through the whole file.
This is sample output - yours may be different.
1

command | sed '/regex/q'

taliver · 2009-12-29 14:52:41 3
Check if file is greater than 20 bytes, such as an empty gzip archive

If you gzip an empty file it becomes 20 bytes. Some backup checks i do check to see if the file is greater than zero size (-s flag) but this is no good here. Im sure someone has a better check than me for this? No check to see if file exists before checking it's size.
This is sample output - yours may be different.
-2

BACKUP_FILE_SIZE=`eval ls -l ${BACKUP_FILE} | awk {'print $5'}`; if [ $BACKUP_FILE_SIZE -le 20 ]; then echo "its empty"; else echo "its not empty"; fi

Redrocket · 2009-12-29 08:34:37 3
Empty a file
This is sample output - yours may be different.
6

> foobar.txt

unixmonkey7657 · 2009-12-29 08:08:15 4
Empty a file
This is sample output - yours may be different.
-1

truncate foobar.txt

w216 · 2009-12-29 01:52:12 3
find out how much space are occuipied by files smaller than 1024K (sic) - improved

The original didn't use -print0 which fails on weird file names eg with spaces. The original parsed the output of 'ls -l' which is always a bad idea.
This is sample output - yours may be different.
2

find dir -size -1024k -type f -print0 | du --files0-from - -bc

bhepple · 2009-12-29 01:33:55 3
Press Any Key to Continue

how to finish command or script without any output Show Sample Output
This is sample output - yours may be different.
```
root@ubuserver:~# read enterKey

root@ubuserver:~#
```
-4

read enterKey

bbmarek · 2009-12-29 00:18:32 7
reload config

reload a configuration from .bashrc file Show Sample Output
This is sample output - yours may be different.
```
root@ubuserver:~# source .bashrc
root@ubuserver:~#
```
0

source .bashrc

bbmarek · 2009-12-29 00:14:34 17
Get your public ip
This is sample output - yours may be different.
0

curl -s http://icanhazip.com/

w216 · 2009-12-28 23:00:37 3
Read just the IP address of a device
This is sample output - yours may be different.
0

ifconfig -l | xargs -n1 ipconfig getifaddr 2> /dev/null

w216 · 2009-12-28 22:45:45 3
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Ask for a password, the passwd-style

You can ask repeatedly for a non-blank password using this function: function read_password() { while [ ! -n "$USER_PASSWORD" ]; do read -s -p"Password: " USER_PASSWORD if [ ! -n "$USER_PASSWORD" ]; then echo "ERROR: You must specify a valid password, please try again" fi echo done } Also you can set a time out (in seconds) to write the password read -t 10 -s -p"Password: " USER_PASSWORD_VARIABLE if [ ! $? -eq 0 ]; then echo "Time out!" fi

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

Apply fade effect to a audio

fade [type] fade-in-length [stop-time [fade-out-length]] Apply a fade effect to the beginning, end, or both of the audio. An optional type can be specified to select the shape of the fade curve: q for quarter of a sine wave, h for half a sine wave, t for linear (`triangular') slope, l for logarithmic, and p for inverted parabola. The default is logarithmic. A fade-in starts from the first sample and ramps the signal level from 0 to full volume over fade-in-length sec? onds. Specify 0 seconds if no fade-in is wanted. For fade-outs, the audio will be truncated at stop-time and the signal level will be ramped from full volume down to 0 starting at fade-out-length seconds before the stop-time. If fade-out-length is not specified, it defaults to the same value as fade-in-length. No fade-out is performed if stop-time is not specified. If the file length can be determined from the input file header and length-changing effects are not in effect, then 0 may be specified for stop-time to indicate the usual case of a fade-out that ends at the end of the input audio stream. All times can be specified in either periods of time or sample counts. To specify time periods use the format hh:mm:ss.frac format. To specify using sample counts, specify the number of samples and append the letter `s' to the sample count (for example `8000s').

ssh autocomplete based on ~/.ssh/config

I sue this in my .bashrc file This will also do auto-completion for scp and sftp

Kill any lingering ssh processes

Also ignoring "sshd" server is necessary since you should not kill ssh server processes.

back ssh from firewalled hosts

host B (you) redirects a modem port (62220) to his local ssh. host A is a remote machine (the ones that issues the ssh cmd). once connected port 5497 is in listening mode on host B. host B just do a ssh 127.0.0.1 -p 5497 -l user and reaches the remote host'ssh. This can be used also for vnc and so on.

Perform a branching conditional

This will perform one of two blocks of code, depending on the condition of the first. Essentially is a bash terniary operator. To tell if a machine is up: $ ping -c1 machine { echo succes;} || { echo failed; } Because of the bash { } block operators, you can have multiple commands $ ping -c1 machine && { echo success;log-timestamp.sh }|| { echo failed; email-admin.sh; } Tips: Remember, the { } operators are treated by bash as a reserved word: as such, they need a space on either side. If you have a command that can fail at the end of the true block, consider ending said block with 'false' to prevent accidental execution

Lists unambigously names of all xml elements used in files in current directory

This set of commands was very convenient for me when I was preparing some xml files for typesetting a book. I wanted to check what styles I had to prepare but coudn't remember all tags that I used. This one saved me from error-prone browsing of all my files. It should be also useful if one tries to process xml files with xsl, when using own xml application.

Which processes are listening on a specific port (e.g. port 80)

swap out "80" for your port of interest. Can use port number or named ports e.g. "http"

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