Commands using echo sorted by votes

Commands using echo (1,545)

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quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean

Quick and easy way of validating a date format of yyyy-mm-dd and returning a boolean, the regex can easily be upgraded to handle "in betweens" for mm dd or to validate other types of strings, ex. ip address. Boolean output could easily be piped into a condition for a more complete one-liner.
This is sample output - yours may be different.
-1

echo 2006-10-10 | grep -c '^[0-9][0-9][0-9][0-9]-[0-9][0-9]-[0-9][0-9]$'

rez0r · 2009-05-11 22:18:43 7
Organize a TV-Series season

It happened to me that I got a season of a tv-show which had all files under the same folder like /home/blah/tv_show/season1/file{1,2,3,4,5,...}.avi But I like to have them like this: /home/blah/tv_show/season1/e{1,2,3,4,5,...}/file{1,2,3,4,5,...}.avi So I can have both the srt and the avi on one folder without cluttering much. This command organizes everything assuming that the filename contains Exx where xx is the number of the episode. You may need to set: IFS=$'\n' if your filenames have spaces.
This is sample output - yours may be different.
-1

season=1; for file in $(ls) ; do dir=$(echo $file | sed 's/.*S0$season$E[0-9]\{2\}$.*/\1/'); mkdir $dir ; mv $file $dir; done

lonecat · 2009-05-27 03:30:58 4
Sort a list of numbers on on line, separated by spaces.

You can replace "sort -nu" with "sort -u" for a word list sorted or "sort -R" for a random-sorted line (edit: corrected) Show Sample Output
This is sample output - yours may be different.
```
$ echo "4 2  3 5  2 52  11" | sed "s/$ \|$$/\n/g" | sort -nu | tr "\n" " "| sed -e "s/^ *//" -e "s/ $//"
2 3 4 5 11 52
```
-1

echo $numbers | sed "s/$ \|$$/\n/g" | sort -nu | tr "\n" " " | sed -e "s/^ *//" -e "s/ $//"

chickenzilla · 2009-06-24 15:12:17 7
dig this
This is sample output - yours may be different.
-1

for dnsREC in $(curl -s http://www.iana.org/assignments/dns-parameters |grep -Eo ^[A-Z\.]+\ |sed 's/TYPE//'); do echo -n "$dnsREC " && dig +short $dnsREC IANA.ORG; done

commandlinefu · 2009-09-01 03:11:18 3
Sort a character string

using awk missed the last char thanks @Josay Show Sample Output
This is sample output - yours may be different.
```
aeeelmoprsst
```
-1

echo sortmeplease | awk '{l=split($1,a,"");asort(a);while(x<=l){printf "%s",a[x];x++ }print "";}'

foob4r · 2009-09-03 10:22:39 4
Capitalize the word with dd
This is sample output - yours may be different.
-1

echo capitalize | { dd bs=1 count=1 conv=ucase 2> /dev/null; cat ;}

twfcc · 2009-09-05 01:49:53 40
search for a file in PATH

search argument in PATH accept grep expressions without args, list all binaries found in PATH Show Sample Output
This is sample output - yours may be different.
```
$ sepath noo
/usr/openwin/bin/ttsnoop
/usr/sbin/snoop
$ sepath ^ps$
/bin/ps
/usr/bin/ps
/usr/ucb/ps
```
-1

function sepath { echo $PATH |tr ":" "\n" |sort -u |while read L ; do cd "$L" 2>/dev/null && find . $ ! -name . -prune $ $ -type f -o -type l $ 2>/dev/null |sed "s@^\./@@" |egrep -i "${*}" |sed "s@^@$L/@" ; done ; }

mobidyc · 2009-09-11 15:03:22 5
search for a file in PATH

Searches in order of the directories of $PATH. Stops after finding the entry; looks for only that fileName. Works in Bourne, Korn, Bash and Z shells. Show Sample Output
This is sample output - yours may be different.
```
/usr/local/bin/fileName
```
-1

for L in `echo :$PATH | tr : '\n'`; do F=${L:-"."}/fileName; if [ -f ${F} -o -h ${F} ]; then echo ${F}; break; fi; done

arcege · 2009-09-11 16:14:36 3
regex to match an ip

Handles everything except octets with 255. Ran through ip generator with variable octet lengths.
This is sample output - yours may be different.
-1

echo 127.0.0.1 | egrep -e '^(([01]?[0-9]{1,2}|2[0-4][0-9]|25[0-4])\.){3}([01]?[0-9]{1,2}|2[0-4][0-9]|25[0-4])$'

arcege · 2009-09-17 17:40:48 3
for loop with leading zero in bash 3

Bash 4 will let you do {00..19} to get leading zeros, but Bash 3 doesn't have that feature. This technique gets you partway there (the sequences need be such that the last digit ranges from zero to nine - you can't use this for something like Bash 4's {03..27}, for example). When this limitation is not a problem, you can avoid some complicated string manipulation for concatenating leading zeros. You can add more digits like this: {0..1}{0..9}{0..9} (ranges from 0 to 99 with up to two leading zeros). To pad with additional zeros: for i in 000{0..1}{0..9}; do echo $i; done or for i in {0..1}{0..9}; do echo "000$i"; done This is useful for creating values to sort or for creating filenames with a fixed format. Note that this will also work: touch {0..1}{0..9} Show Sample Output
This is sample output - yours may be different.
```
00
01
02
03
04
05
06
07
08
09
10
11
12
13
14
15
16
17
18
19
```
-1

for i in {0..1}{0..9}; do echo $i; done

dennisw · 2009-09-18 02:51:12 5
Check if variable is a number
This is sample output - yours may be different.
-1

echo $X | egrep "^[0-9]+$"

sharfah · 2009-10-09 13:59:47 6
Email if you disk is over 90%

Email if you disk is over 90% - www.fir3net.com
This is sample output - yours may be different.
-1

HDD=$(df | awk ' NR>3 (S=$5) (M=$6) { if (S>90) print "Your Systems "M" is """S" Full" } ') ; [[ $HDD ]] && echo "$HDD" | mail -s "Hard-Drives Full" TO@EMAIL.com -- -f FROM@EMAIL.com >/dev/null

felix001 · 2009-10-16 06:52:36 5
Partition a new disk as all one partition tagged as "LInux LVM"

This is a bit hacky, but if you're setting up a bunch of new LUNs, it can save a bunch of time. Also check out sfdisk. The fdisk will fail if, for example, a partition table already exists.
This is sample output - yours may be different.
-1

echo -e "n\np\n1\n\n\nt\n8e\nw" | fdisk /dev/sdX

sud0er · 2009-10-20 16:21:54 5
password generator

make password randomly, default 8 char
This is sample output - yours may be different.
-1

genpass() { local h x y;h=${1:-8};x=( {a..z} {A..Z} {0..9} );y=$(echo ${x[@]} | tr ' ' '\n' | shuf -n$h | xargs);echo -e "${y// /}"; }

twfcc · 2009-10-24 04:05:42 4
Friendly command-not-found message.

This will give you a friendly warning if a command doesn't exists. Show Sample Output
This is sample output - yours may be different.
```
$ aptitypo
...
```
-1

command_not_found_handle() { echo 6661696c626f61742e2e2e0a | xxd -p -r; }

unixmonkey7301 · 2009-12-03 21:33:35 4
Know when you will type :q in your term instead of vi(m), the alias will chewed you out.

For vi(m) users : Add it in your ~/.bashrc Add an "exit" @ the end if you are masochist ;) Show Sample Output
This is sample output - yours may be different.
```
this is NOT vi(m) :/
```
-1

alias :q='tput setaf 1; echo >&2 "this is NOT vi(m) :/"; tput sgr0'

sputnick · 2009-12-08 12:59:44 3
prints line numbers

Yep, is hard, but is a way more flexible using pipe.
This is sample output - yours may be different.
-1

cat infile | while read str; do echo "$((++i)) - $str" ; done;

glaudiston · 2009-12-09 14:05:09 3
prints line numbers

Hi glaudiston, you can save a few chars by leaving out cat and pipe and still enjoy the added flexibility.
This is sample output - yours may be different.
-1

while read str; do echo "$((++i)) - $str"; done < infile

putnamhill · 2009-12-09 15:11:25 3
[Gentoo] Input modules, commented, in your module.autoload file

Whenever you compile a new kernel, there are always new modules. The best way to make sure you have the correct modules loaded when you boot is to add all your modules in the modules.autoload file (they will be commented) and uncomment all those modules you need. Also a good way to keep track of the available modules in your system. For other distros you may have to change the name of the file to /etc/modprobe.conf Show Sample Output
This is sample output - yours may be different.
```
# /etc/modules.autoload.d/kernel-2.6:  kernel modules to load when system boots.
#
# Note that this file is for 2.6 kernels.
#
# Add the names of modules that you'd like to load when the system
# starts into this file, one per line.  Comments begin with # and
# are ignored.  Read man modules.autoload for additional details.

# For example:
# aic7xxx
# mixer-oss.ko
# pcm-oss.ko
# seq-device.ko
# seq-oss.ko
# snd-seq.ko
```
-1

find /lib/modules/`uname -r`/ -type f -iname '*.o' -or -iname '*.ko' |grep -i -o '[a-z0-9]*[-|_]*[0-9a-z]*\.ko$' |xargs -I {} echo '# {}' >>/etc/modules.autoload.d/kernel-2.6

paragao · 2010-01-13 02:12:08 4
displays a reminder message at the specified time
This is sample output - yours may be different.
-1

echo "DISPLAY=$DISPLAY xmessage convert db to innodb" | at 00:00

op4 · 2010-02-04 04:02:35 4
Send web page by e-mail

This will send the web page at $u to recipient@example.com . To send the web page to oneself, recipient@example.com can be replaced by $(whoami) or $USER. The "charset" is UTF-8 here, but any alternative charset of your choice would work. `wget -O - -o /dev/null $u` may be considered instead of `curl $u` . On some systems the complete path to sendmail may be necessary, for instance /sys/pkg/libexec/sendmail/sendmail for some NetBSD.
This is sample output - yours may be different.
-1

{ u="http://twitter.com/commandlinefu"; echo "Subject: $u"; echo "Mime-Version: 1.0"; echo -e "Content-Type: text/html; charset=utf-8\n\n"; curl $u ; } | sendmail $USER

pascalvaucheret · 2010-02-24 04:18:30 5
x bottles of beer on the wall graph

Will create a graph of the results for "x bottles of beer on the wall". Requires Gnuplot. Inspired by an xkcd comic: http://xkcd.com/715/ For sample output see: http://tr.im/xbottlesofbeer Show Sample Output
This is sample output - yours may be different.
```
See http://tr.im/xbottlesofbeer
```
-1

(echo "plot '-' with lines"; for x in $(seq 1 100); do curl -s "http://ajax.googleapis.com/ajax/services/search/web?v=1.0&q=$(echo $x bottles of beer on the wall|sed 's/ /%20/g')"|sed 's/.*"estimatedResultCount":"$[^"]*$".*/\1\n/';done)|gnuplot -persist

matthewbauer · 2010-03-17 21:04:36 4
Split a file into equal size chunks and archive to (e)mail account.

This is just a little snippit to split a large file into smaller chunks (4mb in this example) and then send the chunks off to (e)mail for archival using mutt. I usually encrypt the file before splitting it using openssl: openssl des3 -salt -k <password> -in file.tgz -out file.tgz.des3 To restore, simply save attachments and rejoin them using: cat file.tgz.* > output_name.tgz and if encrypted, decrypt using: openssl des3 -d -salt -k <password> -in file.tgz.des3 -out file.tgz edit: (changed "g" to "e" for political correctness)
This is sample output - yours may be different.
-1

split -b4m file.tgz file.tgz. ; for i in file.tgz.*; do SUBJ="Backup Archive"; MSG="Archive File Attached"; echo $MSG | mutt -a $i -s $SUBJ YourEmail@(E)mail.com

tboulay · 2010-03-20 16:49:19 8
Leap year calculation
This is sample output - yours may be different.
-1

year=2010; math=`echo "$year%4" | bc`; [ ! -z $year ] && [ $math -eq 0 ] && echo "$year is leap year!" || echo "$year isn't leap year";

mvrilo · 2010-03-30 15:33:00 4
Bash function to see if the day ends in

The shell has perfectly adequate pattern matching for simple expressions. Show Sample Output
This is sample output - yours may be different.
```
ok
```
-1

function ends_in_y() { case $(date +%A) in *y ) true ;; * ) false ;; esac } ; ends_in_y && echo ok

unixmonkey9199 · 2010-04-06 22:18:52 3
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Creates a 'path' command that always prints the full path to any file

The command creates an alias called 'path', so it's useful to add it to your .profile or .bash_profile. The path command then prints the full path of any file, directory, or list of files given. Soft links will be resolved to their true location. This is especially useful if you use scp often to copy files across systems. Now rather then using pwd to get a directory, and then doing a separate cut and paste to get a file's name, you can just type 'path file' and get the full path in one operation.

How to run X without any graphics hardware

This starts an X server using Xvfb(1) (no graphics hardware required), then starts a VNC server on the display. Change :1 if there's a conflict with an existing display, and change 800x600x24 to suit your tastes (24 is the bit depth, 800x600 is the size). This command obviously requires X be installed, and also x11vnc(1); both are available via your favourite package manager. You can also use another VNC server of your choosing, as long as DISPLAY is set to the display of Xvfb(1). To change your desktop environment (the default is twm(1), which is rather fail), you can add it to your ~/.xinitrc file (see the startx(1) manpage for details).

Visualizing system performance data

Use wget to download one page and all it's requisites for offline viewing

Kills a process that is locking a file.

Useful when you're trying to unmount a volume and other sticky situations where a rogue process is annoying the hell out of you.

Getting the ip address of eth0

defragment files

Thanks to flatcap for optimizing this command. This command takes advantage of the ext4 filesystem's resistance to fragmentation. By using this command, files that were previously fragmented will be copied / deleted / pasted essentially giving the filesystem another chance at saving the file contiguously. ( unlike FAT / NTFS, the *nix filesystem always try to save a file without fragmenting it ) My command only effects the home directory and only those files with your R/W (read / write ) permissions. There are two issues with this command: 1. it really won't help, it works, but linux doesn't suffer much (if any ) fragmentation and even fragmented files have fast I/O 2. it doesn't discriminate between fragmented and non-fragmented files, so a large ~/ directory with no fragments will take almost as long as an equally sized fragmented ~/ directory The benefits i managed to work into the command: 1. it only defragments files under 16mb, because a large file with fragments isn't as noticeable as a small file that's fragmented, and copy/ delete/ paste of large files would take too long 2. it gives a nice countdown in the terminal so you know how far how much progress is being made and just like other defragmenters you can stop at any time ( use ctrl+c ) 3. fast! i can defrag my ~/ directory in 11 seconds thanks to the ramdrive powering the command's temporary storage bottom line: 1. its only an experiment, safe ( i've used it several times for testing ), but probably not very effective ( unless you somehow have a fragmentation problem on linux ). might be a placebo for recent windows converts looking for a defrag utility on linux and won't accept no for an answer 2. it's my first commandlinefu command

Generate White Noise

This command will generate white noise through your speakers (assuming you have sound enabled). It's good for staying focused, privacy, coping with tinnitus, etc. I use it to test that the sound works.

list files recursively by size

Function to output an ASCII character given its decimal equivalent

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Commands using echo (1,545)

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