Commands tagged bash sorted by votes

Commands tagged bash (821)

sorted by

Calculate days on which Friday the 13th occurs

Simply change the years listed in the first seq, and it will print out all the months in that span of years that have Friday the 13ths in them. Show Sample Output
This is sample output - yours may be different.
```
2010 -> August 
2011 -> May 
2012 -> January April July 
2013 -> September December 
2014 -> June 
2015 -> February March November 
2016 -> May 
2017 -> January October 
2018 -> April July 
```
1

for y in $(seq 1996 2018); do echo -n "$y -> "; for m in $(seq 1 12); do NDATE=$(date --date "$y-$m-13" +%A); if [ $NDATE == 'Friday' ]; then PRINTME=$(date --date "$y-$m-13" +%B);echo -n "$PRINTME "; fi; done; echo; done

suspenderguy · 2018-06-13 20:11:46 240
Compute the average number of KB per file for each dir

Shorter version using --tag
This is sample output - yours may be different.
1

parallel --tag echo '$(du -s {} | awk "{print \$1}") / $(find {} | wc -l)' \| bc -l ::: *

IndustrialJoe · 2018-07-05 18:33:21 273
Calculate days on which Friday the 13th occurs

Alter the years in the first brace expansion to select your year range. Modify date format to your liking but leave " %w" at the end. Show Sample Output
This is sample output - yours may be different.
```
2018 April
2018 July
2019 September
2019 December
2020 March
2020 November
2021 August
2022 May
```
1

for i in {2018..2022}-{01..12}-13; do date --date $i +"%Y %B %w" | sed '/[^5]$/d; s/ 5*$//'; done

justsomeguy · 2018-07-09 15:47:39 246
Process command output line by line in a while loop

This snippet allows to process the output of any bash command line by line.
This is sample output - yours may be different.
1

while read -r line; do echo $line; done < <(YOUR COMMAND HERE);

paulera · 2018-08-13 10:03:11 327
Silently deletes lines containing a specific string in a bunch of files

This command will find all occurrences of one or more patterns in a collection of files and will delete every line matching the patterns in every file
This is sample output - yours may be different.
1

for file in $(egrep 'abc|def' *.sql | cut -d":" -f1 | uniq); do sed -i '/abc/d' ./$file ; sed -i '/def/d' ./$file; done

guillaume1306 · 2018-12-10 16:23:20 30
Get the full path of a bash script's Git repository head.

Rather than complicated and fragile paths relative to a script like "../../other", this command will retrieve the full path of the file's repository head. Safe with spaces in directory names. Works within a symlinked directory. Broken down: cd "$(dirname "${BASH_SOURCE[0]}")" temporarily changes directories within this expansion. Double quoted "$(dirname" and ")" with unquoted ${BASH_SOURCE[0]} allows spaces in the path. git rev-parse --show-toplevel gets the full path of the repository head of the current working directory, which was temporarily changed by the "cd".
This is sample output - yours may be different.
1

$(cd "$(dirname "${BASH_SOURCE[0]}")" && git rev-parse --show-toplevel)

rakurai · 2019-01-19 11:02:17 35
shuffle lines via bash

Using perl in a one-liner is a bit overkill to randomly sort some input. `sort` from coreutils should be enough.
This is sample output - yours may be different.
1

seq 1 9 | sort -R

chtk · 2019-07-05 18:36:49 39
shell bash iterate number range with for loop
This is sample output - yours may be different.
1

rangeBegin=10; rangeEnd=20; for ((numbers=rangeBegin; numbers<=rangeEnd; numbers++)); do echo $numbers; done

forouharid · 2019-07-27 21:04:27 76
Bash alias to output the current Swatch Internet Time

Output the current time in Swatch “Internet Time”, aka .beats. There are 1000 .beats in a day, and @0 is at 00:00 Central European Standard Time. This was briefly a thing in the late 1990s. More details: https://2020.swatch.com/en_ca/internet-time/ The alias is rather quote heavy to protect the subshell, so the bare command is: echo '@'$(TZ=GMT-1 date +'(%-S + %-M * 60 + %-H * 3600) / 86.4'|bc) Show Sample Output
This is sample output - yours may be different.
```
@811
```
1

alias beats='echo '\''@'\''$(TZ=GMT-1 date +'\''(%-S + %-M * 60 + %-H * 3600) / 86.4'\''|bc)'

scruss · 2021-05-27 18:42:21 189
Download mp3 files linked in a RSS podcast feed

Directly download all mp3 files of the desired podcast
This is sample output - yours may be different.
1

curl http://radiofrance-podcast.net/podcast09/rss_14726.xml | grep -Eo "(http|https)://[a-zA-Z0-9./?=_%:-]*mp3" | sort -u | xargs wget

pascalvaucheret · 2021-08-09 13:40:26 179
Infinite loop ssh
This is sample output - yours may be different.
1

until ssh login@10.0.0.1; do echo "Nope, keep trying!"; fi; sleep 10; done

minnmass · 2021-09-29 14:53:55 998
Extract content between the first " and the last " double quotes

Thanks to this user: https://stackoverflow.com/a/35636373/2394635 Show Sample Output
This is sample output - yours may be different.
```
checkin_resumestorevisit \"- "Online_V2.mt
```
1

s='Test "checkin_resumestorevisit \"- "Online_V2.mt" Run'; s=${s#*'"'}; s=${s%'"'*}; echo "$s"

bugmenot · 2022-01-08 16:16:18 365
Add all not commited files to svn
This is sample output - yours may be different.
0

svn st | grep ^? | xargs svn add 2> /dev/null

douglas · 2009-02-25 11:40:51 6
for loop, counting forward for backward

The brace expansion also allows you to count backward: for i in {15..1}; do echo $i; done You can also use this construct to create new file or new directory: mkdir dir{1..3} # Same as mkdir dir1 dir2 dir3
This is sample output - yours may be different.
0

for i in {1..15}; do echo $i; done

haivu · 2009-03-21 23:08:41 5
Compare a file with the output of a command or compare the output of two commands
This is sample output - yours may be different.
0

vimdiff foo.c <(bzr cat -r revno:-2 foo.c)

HorsePunchKid · 2009-03-24 18:15:48 5
Passwordless mysql{,dump,admin} via my.cnf file

The file .my.cnf located at user's home directory is used for mysql login. If this file exists, then mysql -uYOURUSERNAME -pYOURPASSWORD database -e 'SOME SQL COMMAND' can be replaced with mysql database -e 'SOME SQL COMMAND' It saves you from typing! This is valid for mysqladmin and mysqldump commands as well. Show Sample Output
This is sample output - yours may be different.
```
[client]
user = YOURUSERNAME
password = YOURPASSWORD
```
0

echo -e "[client]\nuser = YOURUSERNAME\npassword = YOURPASSWORD" > ~/.my.cnf

alperyilmaz · 2009-03-24 19:05:39 9
Number of seconds to certain unix date

Echos the number of seconds from the current time till the specified time (Example in command is (2**31-1)) aka the Unix epoch. Just replace that number with the specified date (in seconds past Jan. 1st 1970) and it will return the seconds. NOTE: Only works in bash Show Sample Output
This is sample output - yours may be different.
```
908835068
```
0

echo $( (( $( (2**31 -1) ) - $(date +%s) )) )

Chartreuse · 2009-04-02 05:14:23 7
Working random fact generator

This is a working version, though probably clumsy, of the script submitted by felix001. This works on ubuntu and CygWin. This would be great as a bash function, defined in .bashrc. Additionally it would work as a script put in the path. Show Sample Output
This is sample output - yours may be different.
```
The only letter not appearing on the Periodic Table is the letter "J".
```
0

lynx -dump randomfunfacts.com | grep -A 3 U | sed 1D

xizdaqrian · 2009-05-05 07:52:10 12
Frequency Sweep

Generates a frequency sweep from $x to $y, with $d numbers inbetween each step, and with each tone lasting $l milliseconds. Show Sample Output
This is sample output - yours may be different.
```
Sound.
```
0

l=500; x=500; y=200; d=-15;for i in `seq $x $d $y`; do beep -l $l -f $i;done

unixmonkey4581 · 2009-07-07 22:12:20 9
Migrate gems from one ruby installation to another

gemInst.sh: #!/bin/bash for i in $@; do if [ "$1" != "$i" ] then echo /newInstall/gem install $1 -v=\"$i\" /newInstall/gem install $1 -v="$i" if [ "$?" != "0" ] then echo -e "\n\nGEM INSTALL ERROR: $1\n\n" echo "$1" > gemInst.err fi fi done
This is sample output - yours may be different.
0

/originalInstall/gem list | tr -d '(),' | xargs -L 1 sudo ./gemInst.sh

snakerdlk · 2009-07-09 21:46:06 4
Sorting by rows

Save the script as: sort_file Usage: sort_file < sort_me.csv > out_file.csv This script was originally posted by Admiral Beotch in LinuxQuestions.org on the Linux-Software forum. I modified this script to make it more portable. Show Sample Output
This is sample output - yours may be different.
```
Sort values arranged in rows, like:
x3, x5, x1, x4, x7, x2, x6
x11, x13, x14, x8, x10, x12, x9
... ... ... ... ... ... ...
After executing the script, values will be horizontally sorted:
x1, x2, x3, x4, x5, x6, x7
x8, x9, x10, x11, x12, x13, x14
... ... ... ... ... ... ...
where x1, x2, ..., xn are integers
Each row can have n integers and 
x1 < x2 < x3, ..., < x7
x8 < x9 < x10, ..., < x14
..   ..   ..           ..
After executing the script, each row will be sorted in ascending order.
```
0

infile=$1 for i in $(cat $infile) do echo $i | tr "," "\n" | sort -n | tr "\n" "," | sed "s/,$//" echo done

iframe · 2009-07-12 21:23:37 6
Generate Files with Random Content and Size in Bash

Create a bunch of random files with random binary content. Basically dd dumps randomly from your hard disk to files random-file*. Show Sample Output
This is sample output - yours may be different.
```
random-file.5
random-file.6
random-file.7
random-file.8
random-file.9
```
0

no_of_files=10; counter=1; while [[ $counter -le $no_of_files ]]; do echo Creating file no $counter; dd bs=1024 count=$RANDOM skip=$RANDOM if=/dev/sda of=random-file.$counter; let "counter += 1"; done

rajaseelan · 2009-07-31 16:34:47 5
Do a search-and-replace in a file after making a backup

"&&" runs sed if and only if the backup completed and /bin/cp exited cleanly. Works for multiple files; just specify multiple filenames (or glob). Use -v switch for cp to play it safe.
This is sample output - yours may be different.
0

for file in <filename>; do cp $file{,.bak} && sed 's/old/new/g' $file.bak > $file; done

Cenobite · 2009-08-25 16:19:45 5
for loop with leading zeros

Uses 'seq' with formatting parameter to generate the necessary padded sequence. Change '%02.0f' to how many digits you need (for 3, use %03.0f, etc) and replace 5 & 15 with your desired min and max. Show Sample Output
This is sample output - yours may be different.
```
05
06
07
08
09
10
11
12
13
14
15
```
0

for s in `seq -f %02.0f 5 15`; do echo $s; done

Yeraze · 2009-09-18 13:21:38 6
for loop with leading zero in bash 3

emulates bash4's "echo {03..20}" Uses bash3 builtin function printf Show Sample Output
This is sample output - yours may be different.
```
03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20
```
0

printf "%02u " {3..20}; echo

Escher · 2009-09-18 18:48:41 4
‹ First < 17 18 19 20 21 > Last ›

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again. That way others can gain from your CLI wisdom and you from theirs too. All commands can be commented on, discussed and voted up or down.

Share Your Commands

Check These Out

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"

Directory bookmarks

pushd and popd are your friends, but sometimes they're just incompatible with the way one works... Two shell functions: bm bookmarkname - "bookmarks" the current directory, just 'cd $BMbookmarkname' to return to it. forget bookmarkname - unsets the 'bookmarkname' variable. It isn't mandatory, they cease to exist when the session ends.

Lists the size of certain file in every 10 seconds

watch is a command especially designed for doing this job

scp a good script from host A which has no public access to host C, but with a hop by host B

middlehost allows ssh access from where you are but not securehost. Use nice ssh piping to simulate scp through A => B => C setting up the shell function if left as an exercise for the reader. ;-) Agent forwarding should avoid password typing.

Copy input sent to a command to stderr

In the above example 'muspi merol' (the output of the first rev command) is sent to stderr and 'lorem ipsum' (the output of the second rev command) is sent to stdout. rev reverse lines of a file or files. This use of tee allows testing if a program correctly handles its input without using files that hold the data.

Find usb device in realtime

Using this command you can track a moment when usb device was attached.

SSH tunneling self-connection

- port 8080 on localhost will be a SOCKSv5 proxy - at localhost:localport1 you will be connected to the external source server1:remoteport1 and at bind_address2:localport2 to server2:remoteport2 - you will be using only IPv4 and arcfour/blowfish-cbc, in order to speed up the tunnel - if you lose the connection, autossh will resume it at soon as possible - the tunnel is here a background process, wiithout any terminal window open

ubuntu easter eggs

Short Information about loaded kernel modules

I modify 4077 and marssi commandline to simplify it and skip an error when parsing the first line of lsmod (4077). Also, it's more concise and small now. I skip using xargs ( not required here ). This is only for GNU sed. For thoses without GNU sed, use that : $ modinfo $(lsmod | awk 'NR>1 {print $1}') | sed -e '/^dep/s/$/\n/g' -e '/^file/b' -e '/^desc/b' -e '/^dep/b' -e d

Adding Color Escape Codes to global CC array for use by echo -e

I was looking for the fastest way to create a bunch of ansi escapes for use in echo -e commands throughout a lot of my shell scripts. This is what I came up with, and I actually stick that loop command in a function and then just call that at the beginning of my scripts to not clutter the environment with these escape codes, which can wreck havok on my terminal when I'm dumping the environment. More of a cool way to store escape ansi codes in an array. You can echo them like: $ echo -e "${CC[15]}This text is black on bright green background." I usually just use with a function: $ # setup_colors - Adds colors to array CC for global use $ # 30 - Black, 31 - Red, 32 - Green, 33 - Yellow, 34 - Blue, 35 - Magenta, 36 - Blue/Green, 37 - White, 30/42 - Black on Green '30\;42' $ function setup_colors(){ declare -ax CC; for i in `seq 0 7`;do ii=$(($i+7));CC[$i]="\033[1;3${i}m";CC[$ii]="\033[0;3${i}m";done;CC[15]="\033[30;42m"; export R='\033[0;00m';export X="\033[1;37m"; }; $ export -f setup_colors CC[15] has a background of bright green which is why it is separate. R resets everything, and X is my default font of bright white. $ CC[15]="\033[30;42m"; R=$'\033[0;00m'; X=$'\033[1;37m' Those are just my favorite colors that I often use in my scripts. You can test which colors by running $ for i in $(seq 0 $((${#CC[@]} - 1))); do echo -e "${CC[$i]}[$i]\n$R"; done See: http://www.askapache.com/linux-unix/bash_profile-functions-advanced-shell.html for more usage.

Stay in the loop…

Follow the Tweets.

Every new command is wrapped in a tweet and posted to Twitter. Following the stream is a great way of staying abreast of the latest commands. For the more discerning, there are Twitter accounts for commands that get a minimum of 3 and 10 votes - that way only the great commands get tweeted.

» http://twitter.com/commandlinefu
» http://twitter.com/commandlinefu3
» http://twitter.com/commandlinefu10

Subscribe to the feeds.

Use your favourite RSS aggregator to stay in touch with the latest commands. There are feeds mirroring the 3 Twitter streams as well as for virtually every other subset (users, tags, functions,…):

Subscribe to the feed for:

» all commands
» commands with 3 up-votes (commandlinefu3)
» commands with 10 up-votes (commandlinefu10)
» commands tagged bash

Commands tagged bash (821) the last day the last week the last month all time sorted by date votes

What's this?

Check These Out

Stay in the loop…

Commands tagged bash (821)

sorted by