Hide

What's this?

commandlinefu.com is the place to record those command-line gems that you return to again and again.

Delete that bloated snippets file you've been using and share your personal repository with the world. 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.

Get involved!

You can sign-in using OpenID credentials, or register a traditional username and password.

OpenID
or
Sign in Register

First-time OpenID users will be automatically assigned a username which can be changed after signing in.

UpGuard checks and validates configurations for every major OS, network device, and cloud provider.
Hide

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:

Hide

News

May 19, 2015 - A Look At The New Commandlinefu
I've put together a short writeup on what kind of newness you can expect from the next iteration of clfu. Check it out here.
March 2, 2015 - New Management
I'm Jon, I'll be maintaining and improving clfu. Thanks to David for building such a great resource!
Hide

Top Tags


awk, bash, curl, find, grep, Linux, sed
Hide

Functions

Commands using printf from sorted by
Terminal - Commands using printf - 166 results
set-proxy () { P=webproxy:1234; DU="fred"; read -p "username[$DU]:" USER; printf "%b"; UN=${USER:-$DU}; read -s -p "password:" PASS; printf "%b" "\n"; export http_proxy="http://${UN}:${PASS}@$P/"; export ftp_proxy="http://${UN}:${PASS}@$P/"; }
2010-02-04 13:12:59
User: shadycraig
Functions: export printf read set
Tags: wget password proxy http_proxy
1
Up
Down
Configuring proxy client on terminal without leaving password on screen or in bash_history

Prompts the user for username and password, that are then exported to http_proxy for use by wget, yum etc

Default user, webproxy and port are used.

Using this script prevent the cleartext user and pass being in your bash_history and on-screen

Show sample output | Comments (5) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%d\n" \0x64
2010-01-09 02:50:50
User: 4Aiur
Functions: printf
-2
Up
Down
hexadecimal2decimal
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%50s\n"|tr ' ' -
2010-01-07 08:49:46
User: rodolfoap
Functions: printf tr
-2
Up
Down
Print a row of 50 hyphens

Better -and faster- using bash printf.

Show sample output | Comments (3) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "\e[8;70;180;t"
2010-01-07 05:58:16
User: jearsh
Functions: printf
Tags: printf resize window
4
Up
Down
Resize a Terminal Window

Replace 70 with the desired height.

Replace 180 with the desired width.

I put it in my bashrc, because by default my terminal is too small.

Comments (8) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
p(){ printf "\033[%d;%dH\033[4%dm \033[m" $((RANDOM%LINES+1)) $((RANDOM%COLUMNS+1)) $((RANDOM%8)); }; clear;while :;do p; sleep .001;done
2009-12-17 15:25:28
User: cfajohnson
Functions: printf sleep
Tags: color
2
Up
Down
Random colours at random locations
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
COL=$(( $(tput cols) / 2 )); clear; tput setaf 2; while :; do tput cup $((RANDOM%COL)) $((RANDOM%COL)); printf "%$((RANDOM%COL))s" $((RANDOM%2)); done
2009-12-15 02:48:28
User: sputnick
Functions: printf tput
Tags: color
6
Up
Down
Another Matrix Style Implementation
Comments (4) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%s\n" !(pattern) ## ksh, or bash with shopt -s extglob
2009-11-26 14:09:56
User: cfajohnson
Functions: bash printf
Tags: ls grep
-1
Up
Down
List files that DO NOT match a pattern

There's no need for ls or grep; printf is builtin to most modern shells

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
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
Tags: bash sed xa urldecod
2
Up
Down
urldecoding

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

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%s\n" .*
2009-11-23 18:07:18
User: cfajohnson
Functions: printf
Tags: dotfiles
0
Up
Down
Find all dot files and directories

In most modern shells, printf is a builtin command.

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%s\n" ${PATH//:/\/* }
2009-11-20 22:55:59
User: cfajohnson
Functions: printf
Tags: list PATH
7
Up
Down
List all available commands (bash, ksh93)
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%s\n" .*
2009-11-20 21:41:02
User: cfajohnson
Functions: printf
Tags: egrep ls dotfiles
1
Up
Down
Find all dot files and directories
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cat *.c | { printf "se te du\nplot '-' t '' w dots\n"; tr '[[:upper:]]' '[[:lower:]]' | tr -s [[:punct:][:space:]] '\n' | sort | uniq -c | sort -nr | head -n 100 | awk '{print $1}END{print "e"}'; } | gnuplot
2009-11-20 14:53:26
User: taliver
Functions: awk cat head printf sort tr uniq
5
Up
Down
Plot frequency distribution of words from files on a terminal.

Uses the dumb terminal option in gnuplot to plot a graph of frequencies. In this case, we are looking at a frequency analysis of words in all of the .c files.

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
export I=$(date +%s); watch -t -n 1 'T=$(date +%s);E=$(($T-$I));hours=$((E / 3600)) ; seconds=$((E % 3600)) ; minutes=$((seconds / 60)) ; seconds=$((seconds % 60)) ; echo $(printf "%02d:%02d:%02d" $hours $minutes $seconds) | toilet -f shadow'
2009-10-23 07:56:30
User: m33600
Functions: date echo export printf watch
0
Up
Down
StopWatch, toilet version, amazing format inside terminal

already described on the other two versions, this one uses ascii characters on game style to display elapsed time.

Show sample output | Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
export I=$(date +%s); watch -t -n 1 'T=$(date +%s);E=$(($T-$I));hours=$((E / 3600)) ; seconds=$((E % 3600)) ; minutes=$((seconds / 60)) ; seconds=$((seconds % 60)) ; echo $(printf "%02d:%02d:%02d" $hours $minutes $seconds) | osd_cat -o 20 -d 1 -p bottom'
2009-10-23 07:47:11
User: m33600
Functions: date echo export printf watch
0
Up
Down
StopWatch, OnScreen version, blinking shily on all desktops

Variation of the theme, this one blinks in low profile on top level of X, ie, it is visible, indeed small.

Try changing fonts and sizes of osd_cat

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
export I=$(date +%s); watch -t -n 1 'T=$(date +%s);E=$(($T-$I));hours=$((E / 3600)) ; seconds=$((E % 3600)) ; minutes=$((seconds / 60)) ; seconds=$((seconds % 60)) ; echo $(printf "%02d:%02d:%02d" $hours $minutes $seconds)'
2009-10-23 07:31:44
User: m33600
Functions: date echo export printf watch
3
Up
Down
StopWatch, simple text, hh:mm:ss using Unix Time

Works on real time clock, unix time based, decrementing the actual time from initial time saved in an environment variable exported to child process inside watch

Shows elapsed time from start of script in hh:mm:ss format

Non afected by system slow down due to the use of date.

Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
ord() { printf "%d\n" "'$1"; }
2009-10-17 22:02:52
User: zude
Functions: printf
1
Up
Down
Get decimal ascii code from character

printf treats first char after single ' as numeric equivalent

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%d\n" "'A" "'B"
2009-10-17 09:50:44
User: twfcc
Functions: printf
1
Up
Down
get the ascii number with bash builtin printf
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
chr() { printf \\$(printf %o $1); }
2009-10-16 19:10:44
User: zude
Functions: printf
Tags: ascii decimal convert
2
Up
Down
Function to output an ASCII character given its decimal equivalent
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
chr () { printf \\$(($1/64*100+$1%64/8*10+$1%8)); }
2009-10-15 07:01:54
User: dennisw
Functions: printf
Tags: ascii decimal convert
5
Up
Down
Function to output an ASCII character given its decimal equivalent

I've corrected the function. My octal conversion formula was completely wrong. Thanks to pgas at http://mywiki.wooledge.org/BashFAQ/071 for setting me straight. The new function is from pgas and is very fast.

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
(printf "PERMISSIONS LINKS OWNER GROUP SIZE MONTH DAY HH:MM PROG-NAME\n" \ ; ls -l | sed 1d) | column -t
2009-10-08 11:53:38
User: opexxx
Functions: column ls printf sed
Tags: sed ls column printf
3
Up
Down
Using column to format a directory listing

Using column to format a directory listing

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
cat file.txt | while read line; do printf "%7.2f -> %7.2f\n" $line; done
2009-10-06 07:09:23
User: opexxx
Functions: cat printf read
0
Up
Down
Bashbuiltin printf
Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
find -type f -name "*.avi" -print0 | xargs -0 mplayer -vo dummy -ao dummy -identify 2>/dev/null | perl -nle '/ID_LENGTH=([0-9\.]+)/ && ($t +=$1) && printf "%02d:%02d:%02d\n",$t/3600,$t/60%60,$t%60' | tail -n 1
2009-09-24 15:50:39
User: syssyphus
Functions: find perl printf tail xargs
Tags: video audio mplayer perl find
10
Up
Down
Get the total length of all video / audio in the current dir (and below) in H:m:s

change the *.avi to whatever you want to match, you can remove it altogether if you want to check all files.

Comments (77) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf "%02u " {3..20}; echo
2009-09-18 18:48:41
User: Escher
Functions: printf
Tags: bash strings
0
Up
Down
for loop with leading zero in bash 3

emulates bash4's "echo {03..20}"

Uses bash3 builtin function printf

Show sample output | Comments (1) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
yes "$(seq 1 255)" | while read i; do printf "\x1b[48;5;${i}m\n"; sleep .01; done
2009-09-05 04:01:23
User: unixmonkey4581
Functions: printf read sleep yes
11
Up
Down
cycle through a 256 colour palette

Rainbow, instead of greys

Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate
printf '%*s\n' 20 | tr ' ' '#'
2009-08-15 22:38:01
User: twfcc
Functions: printf tr
0
Up
Down
Emulate perl 'print "#" x 20, "\n"'
Comments (0) | Add to favourites | Report as malicious | Submit alternative | Report as a duplicate