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Commands tagged bash from sorted by
Terminal - Commands tagged bash - 724 results
php -i | grep php.ini
2009-12-23 15:52:20
User: jemmille
Functions: grep
Tags: bash grep PHP

Quick and easy way to find out which php.ini file is being used. Especially useful if you just need to find the location of the file for editing purposes.

vim -n -es -c 'g/# CommandParse/+2,/^\s\+esac/-1 d p | % d | put p | %<' -c 'g/^\([-+]\+[^)]\+\))/,/^\(\s\+[^- \t#]\|^$\)/-1 p' -c 'q!' $0
2009-12-19 08:32:00
User: syladmin
Functions: vim

A really fun vim oneliner for auto documenting your option's parsing in your script.

# print the text embeded in the case that parse options from command line.

# the block is matched with the marker 'CommandParse' in comment, until 'esac'



# use vim for parsing:

# 1st grep the case block and copy in register @p + unindent in the buffer of the file itself

# 2nd filter lines which start with --opt or +opt and keep comment on hte following lines until an empty line

# 3rd discard changes in the buffer and quit

vim -n -es -c 'g/# CommandParse/+2,/^\s\+esac/-1 d p | % d | put p | %

-c 'g/^\([-+]\+[^)]\+\))/,/^\(\s\+[^- \t#]\|^$\)/-1 p' \

-c 'q!' $0


example code:http://snipplr.com/view/25059/display-embeded-comments-for-every-opt-usefull-for-auto-documenting-your-script/

p() { l=$LINES; case $1 in do) shift; IFS=$'\n' _pg=( $("$@") ) && _pgn=0 && p r;; r) echo "${_pg[*]:_pgn:$((l-4))}";; d) (( _pgn+=l-4 )); (( _pgn=_pgn>=${#_pg[@]}?${#_pg[@]}-l+4:_pgn )); p r;; u) (( _pgn=_pgn<=l-4?0:_pgn-$l-4 )); p r;; esac; }
2009-12-18 23:35:53
User: intuited
Functions: echo
Tags: bash pager

Manpages, command summaries, and pretty much everything else usually have the information you're most likely to want at the beginning. Seeing just the last 40 or so lines of options from a command that has 100 is not super useful, and having to scroll up each time you want to glance at something is spastic.

Run this and then do something like

p do vi --help

and you'll get the first screen(-mostly-)full of vi's usage info and options list

Then use

p d

to page down, and

p u

to page up.

To see the current page again:

p r

Also useful for situations like

p do aptitude search ~dsmorgasbord p next #p sudo aptitude -r install libwickedawesome-perl-snoochieboochies p next p sudo aptitude -r install libwickedawesome-perl-snoochieboochies snazztasticorama-dev-v0.&#8734;

where you're using readline up-arrow, HOME, END, etc., to quickly recall commented commands.

For the unaware, that option to aptitude search will bring up all of the packages whose descriptions contain the string "smorgasbord". Depending on your distro, there could potentially be hundreds of them.

while [ 1 ]; do banner 'ze missiles, zey are coming! ' | while IFS="\n" read l; do echo "$l"; sleep 0.01; done; done
2009-12-14 07:40:07
User: craigds
Functions: banner echo read sleep

Displays a scrolling banner which loops until you hit Ctrl-C to terminate it.

Make sure you finish your banner message with a space so it will loop nicely.

dd if=/dev/sda | tee >(dd of=/dev/sdb) | dd of=/dev/sdc
2009-12-11 17:34:38
User: nerd65536
Functions: dd tee
Tags: bash tee dd pipe root

If you have some drive imaging to do, you can boot into any liveCD and use a commodity machine. The drives will be written in parallel.

To improve efficiency, specify a larger block size in dd:

dd if=/dev/sda bs=64k | tee >(dd of=/dev/sdb bs=64k) | dd of=/dev/sdc bs=64k

To image more drives , insert them as additional arguments to tee:

dd if=/dev/sda | tee >(dd of=/dev/sdb) >(dd of=/dev/sdc) >(dd of=/dev/sdd) | dd of=/dev/sde
while read str; do echo "$((++i)) - $str"; done < infile
2009-12-09 15:11:25
User: putnamhill
Functions: echo read
Tags: bash

Hi glaudiston, you can save a few chars by leaving out cat and pipe and still enjoy the added flexibility.

find . -type d -exec sh -c "normalize-audio -b \"{}\"/*.mp3" \;
2009-12-08 03:13:13
Functions: find sh

Execute this in the root of your music library and this recurses through the directories and normalizes each folder containing mp3s as a batch. This assumes those folders hold an album each. The command "normalize-audio" may go by "normalize" on some systems.

while read n; do host $n; done < list
perl -e '$_=`ifconfig eth0`;/\d+.\d+.\d+.\d+ /; print $&,"\n";'
2009-12-05 14:24:48
Functions: perl

If you are interested in interfaces other than eth0 you will need to change eth0 to your interface name.

You could use this mammoth to nab the ip4 addresses of all your interfaces

perl -e '@_=`ifconfig -a`; sort(@_); foreach(@_) { /(inet addr\:)(\d+.\d+.\d+.\d+ )/; $_=$2; @uniq=grep($_ ne $prev && (($prev) = $_), @_);} print join "\n",@uniq,"\n"; '

it seems silly to have all this code when the following will work fine

ifconfig -a | grep "inet " | awk -F":" ' { print $2 } ' | cut -d " " -f1

wget `lynx --dump http://xkcd.com/|grep png`
lynx --dump --source http://www.xkcd.com | grep `lynx --dump http://www.xkcd.com | egrep '(png|jpg)'` | grep title | cut -d = -f2,3 | cut -d '"' -f2,4 | sed -e 's/"/|/g' | awk -F"|" ' { system("display " $1);system("echo "$2); } '
2009-12-03 18:53:57
Functions: awk cut egrep grep

Same thing just a different way to get there. You will need lynx

some_command > >(/bin/cmd_for_stdout) 2> >(/bin/cmd_for_stderr)
2009-12-01 03:58:04
User: tylerl

You can use [n]> combined with >(cmd) to attach the various output file descriptors to be the input of different commands.

sudo echo 0 > /sys/block/sdb/queue/rotational
2009-11-27 12:16:17
User: nickleus
Functions: echo sudo

if you still get a permissions error using sudo, then nano the file:

sudo nano -w /sys/block/sdb/queue/rotational

and change 1 to 0

this thread:


says that this will "help the block layer to optimize a few decisions"

iostat -m -d /dev/sda1
2009-11-27 12:00:48
User: nickleus

The iostat command is used for monitoring system input/output device loading by observing the time the devices are active in relation to their average transfer rates.

in ubuntu to get the iostat program do this:

sudo apt-get install sysstat

i found this command here:


xkcd(){ wget -qO- http://xkcd.com/|tee >(feh $(grep -Po '(?<=")http://imgs[^/]+/comics/[^"]+\.\w{3}'))|grep -Po '(?<=(\w{3})" title=").*(?=" alt)';}
2009-11-27 09:11:47
User: eightmillion
Functions: grep tee wget

This function displays the latest comic from xkcd.com. One of the best things about xkcd is the title text when you hover over the comic, so this function also displays that after you close the comic.

To get a random xkcd comic, I also use the following:

xkcdrandom(){ wget -qO- dynamic.xkcd.com/comic/random|tee >(feh $(grep -Po '(?<=")http://imgs[^/]+/comics/[^"]+\.\w{3}'))|grep -Po '(?<=(\w{3})" title=").*(?=" alt)';}
colordiff -yW"`tput cols`" /path/to/file1 /path/to/file2
2009-11-26 18:00:53
User: dweomer21

Barely worth posting because it is so simple, but I use it literally all the time. I was always frustrated by the limitations that a non-gui environment imposes on diff'ing files. This fixes some of those limitations by colourising the output (you'll have to install colordiff, but it is just a wrapper for diff itself), using side-by-side mode for clearer presentation, and of course, the -W parameter, using tput to automatically insert you terminal width. Note that the double quotes aren't necessary if typed into terminal as-is. I included them for safety sake,

2009-11-25 06:48:37
User: bhepple
Tags: bash getopt

This will make your bash scripts better!!

process-getopt is a wrapper around getopt(1) for bash that lets you define command line options (eg -h, --help) and descriptions through a single function call. These definitions are then used in runtime processing of command line options as well as in generating help and man pages. It also saves a little time in coding and in producing nicely formatted documentation. It is quite similar to GNU's argp in glibc for compiled languages and OptionParse for python.

See: Linux Gazette article 162: http://tldp.org/LDP/LGNET/162/hepple.html,

http://sourceforge.net/projects/process-getopt, http://bhepple.freeshell.org/oddmuse/wiki.cgi/process-getopt

printf $(echo -n $1 | sed 's/\\/\\\\/g;s/\(%\)\([0-9a-fA-F][0-9a-fA-F]\)/\\x\2/g')
2009-11-25 04:27:39
User: infinull
Functions: echo printf sed

My version uses printf and command substitution ($()) instead of echo -e and xargs, this is a few less chars, but not real substantive difference.

Also supports lowercase hex letters and a backslash (\) will make it through unescaped

function decToBin { echo "ibase=10; obase=2; $1" | bc; }
2009-11-24 22:57:58
User: woxidu
Functions: echo

Convert some decimal numbers to binary numbers. You could also build a general base-converter:

function convBase { echo "ibase=$1; obase=$2; $3" | bc; }

then you could write

function decToBun { convBase 10 2 $1; }
awk '/q=/{print $11}' /var/log/httpd/access_log.4 | awk -F 'q=' '{print $2}' | sed 's/+/ /g;s/%22/"/g;s/q=//' | cut -d "&" -f 1
cat /var/log/httpd/access_log | grep q= | awk '{print $11}' | awk -F 'q=' '{print $2}' | sed 's/+/ /g;s/%22/"/g;s/q=//' | cut -d "&" -f 1 | mail [email protected] -s "[your-site] search strings for `date`"
2009-11-22 03:03:06
User: isma
Functions: awk cat grep sed strings

It's not a big line, and it *may not* work for everybody, I guess it depends on the detail of access_log configuration in your httpd.conf. I use it as a prerotate command for logrotate in httpd section so it executes before access_log rotation, everyday at midnight.

(echo CD_DA; for f in {01..99}; do echo "$f Hz">&2; sox -nt cdda -r44100 -c2 $f.cdda synth 30 sine $f; echo TRACK AUDIO; echo FILE \"$f.cdda\" 0; done) > cdrdao.toc && cdrdao write cdrdao.toc && rm ??.cdda cdrdao.toc
2009-11-17 06:23:42
User: hackerb9
Functions: cdrdao echo rm write

This command creates and burns a gapless audio CD with 99 tracks. Each track is a 30 second sine wave, the first is 1 Hz, the second 2 Hz, and so on, up to 99 Hz. This is useful for testing audio systems (how low can your bass go?) and for creating the constant vibrations needed to make non-Newtonian fluids (like cornstarch and water) crawl around.

Note, this temporarily creates 500MB of .cdda files in the current directory. If you don't use the "rm" at the end of the command, you can burn more disks using

cdrdao write cdrdao.toc

Prerequisites: a blank CD-R in /dev/cdrw, sox (http://sox.sourceforge.net/), and cdrdao (http://cdrdao.sourceforge.net/). I'm also assuming a recent version of bash for the brace expansion (which just looks nicer than using seq(1), but isn't necessary).

albumart(){ local y="$@";awk '/View larger image/{gsub(/^.*largeImagePopup\(.|., .*$/,"");print;exit}' <(curl -s 'http://www.albumart.org/index.php?srchkey='${y// /+}'&itempage=1&newsearch=1&searchindex=Music');}
2009-11-15 19:54:16
User: eightmillion

This bash function uses albumart.org to find the cover for an album. It returns an amazon.com url to the image.

Usage: albumart [artist] [album]

These arguments can be reversed and if the album name is distinct enough, it may be possible to omit the artist.

The command can be extended with wget to automatically download the matching image like this:

albumart(){ local x y="$@";x=$(awk '/View larger image/{gsub(/^.*largeImagePopup\(.|., .*$/,"");print;exit}' <(curl -s 'http://www.albumart.org/index.php?srchkey='${y// /+}'&itempage=1&newsearch=1&searchindex=Music'));[ -z "$x" ]&&echo "Not found."||wget "$x" -O "${y}.${x##*.}";}
psu(){ command ps -Hcl -F S f -u ${1:-$USER}; }
2009-11-13 06:10:33
User: AskApache
Functions: command ps

An easy function to get a process tree listing (very detailed) for all the processes of any gived user.

This function is also in my http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html

curl -s -c /tmp/cookie -k -u tivo:$MAK --digest http://$tivo/download/$filename | tivodecode -m $MAK -- - | mplayer - -cache-min 50 -cache 65536