Commands using echo sorted by votes

Commands using echo (1,545)

sorted by

Generate a sequence of numbers.
This is sample output - yours may be different.
0

echo {1..99}

wolfpup · 2018-11-11 01:04:22 605
Generate a sequence of numbers.

Uses bash shortcut to generate series, it works with letters too echo {A..H} echo {a..h} Be careful not to mix upper and lower case, you may encounter funny results : echo {z..A} z y x w v u t s r q p o n m l k j i h g f e d c b a ` _ ^ ] [ Z Y X W V U T S R Q P O N M L K J I H G F E D C B A Show Sample Output
This is sample output - yours may be different.
```
1 2 3 4 5 6 7 8 9 10 11 12
```
0

echo {1..12}

keltroth · 2018-11-12 14:09:26 367
converts all pngs in a folder to webp, quality can be choosed as a argument

needs cwebp
This is sample output - yours may be different.
0

pngwebp(){ arg1=$1 for i in *.png; do name=`echo "${i%.*}"`; echo $name; cwebp -q $1 "${i}" -o "${name}.webp" done }

k2arim99 · 2018-12-01 14:38:05 903
OSX script to change Terminal profiles based on machine name; use with case statement parameter matching

/macos/mojave shell script to change terminal profiles
This is sample output - yours may be different.
0

echo "tell application \"Terminal\"\n\t set its current settings of selected tab of window 1 to settings set \"$PROFILE\"\n end tell"|osascript;

christoph000 · 2018-12-19 23:48:12 34
check web server port 80 response header

check web server port 80 response header Show Sample Output
This is sample output - yours may be different.
```
HTTP/1.1 200 OK
Server: Apache 2.4.1
Date: Wed, 17 Apr 2019 17:56:50 GMT
Content-Type: text/html
Content-Length: 307
Last-Modified: Sat, 14 Jan 2017 22:01:22 GMT
Connection: close
ETag: "587a9fb2-133"
X-Frame-Options: SAMEORIGIN
Accept-Ranges: bytes
```
0

(echo -e 'GET / HTTP/1.0\r\n\r\n';) | ncat <IPaddress> 80

aysadk · 2019-04-17 18:09:28 34
Random number with a normal distribution between 1 and X

Print a random number between 1 and 50 with a normal distribution around the center. The numbers around the middle are the most likely to occur and the farther you get from that the less and less common they are. You can test this and observe the number distribution with this command: for i in `seq 100000`; do echo $[(${RANDOM}%40+${RANDOM}%40)/2+1]; done | sort -n | uniq -c Show Sample Output
This is sample output - yours may be different.
```
30
```
0

echo $[(${RANDOM}%100+${RANDOM}%100)/2+1]

varenc · 2019-05-16 00:58:25 40
automatically generate the ip/hostname entry for the /etc/hosts in the current system

I use it after a clean CentOS 7 minimal server installation to automatically populate the /etc/hosts file. Not sure why the installation does not add this entry by itself. Tested on CentOS 7 with the simplest use case: 1 static ip address and the hostname provided during installation. Show Sample Output
This is sample output - yours may be different.
```
[root@dns-server ~]# echo "$(ip addr show dev $(ip r | grep -oP 'default.*dev \K\S*') | grep -oP '(?<=inet )[^/]*(?=/)') $(hostname -f) $(hostname -s)"
10.0.2.10 dns-server.mydomain.lab dns-server

[root@dns-server ~]# echo "$(ip addr show dev $(ip r | grep -oP 'default.*dev \K\S*') | grep -oP '(?<=inet )[^/]*(?=/)') $(hostname -f) $(hostname -s)" >> /etc/hosts

[root@dns-server ~]# cat /etc/hosts
127.0.0.1   localhost localhost.localdomain localhost4 localhost4.localdomain4
::1         localhost localhost.localdomain localhost6 localhost6.localdomain6
10.0.2.10 dns-server.mydomain.lab dns-server
```
0

echo "$(ip addr show dev $(ip r | grep -oP 'default.*dev \K\S*') | grep -oP '(?<=inet )[^/]*(?=/)') $(hostname -f) $(hostname -s)"

acavagni · 2019-06-15 16:40:38 42
Set user password without passwd
This is sample output - yours may be different.
0

echo 'user:newpassword' | chpasswd

wuseman1 · 2019-07-06 23:58:47 40
Download certificate from FTP
This is sample output - yours may be different.
0

echo | openssl s_client -servername ftp.domain.com -connect ftp.domain.com:21 -starttls ftp 2>/dev/null | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p'

Raboo · 2019-07-19 12:30:19 222
pretty print json block that has quotes escaped
This is sample output - yours may be different.
0

echo 'json_here' | sed 's/\\//g' | jq .

jgleeson · 2019-07-19 16:26:48 339
bash test check validate if variable is number

to test check if given variable is a digit / number Show Sample Output
This is sample output - yours may be different.
```
error: Not a number
```
0

varNUM=12345; re='^[0-9]+$'; if ! [[ $varNUM =~ $re ]] ; then echo "error: Not a number"; fi

aysadk · 2019-07-26 09:15:37 574
Check whether laptop is running on battery or cable

Just an alternative for `acpi -b` Show Sample Output
This is sample output - yours may be different.
```
Discharging 46%
```
0

eval "$(printf "echo %s \$((%i * 100 / %i))\n" $(cat $(find /sys -name energy_now 2>/dev/null | head -1 | xargs dirname)/{status,energy_{now,full}}))%"

glaudiston · 2019-08-10 16:50:12 890
Print all git repos from a user

Python is installed on many boxes (in case you could not afford installing jq).
This is sample output - yours may be different.
0

curl -s "https://api.github.com/users/<username>/repos?per_page=1000" | python <(echo "import json,sys;v=json.load(sys.stdin);for i in v:; print(i['git_url']);" | tr ';' '\n')

grault · 2019-12-07 10:49:58 108

List SAN Domains for a certificate Show Sample Output

echo | openssl s_client -connect google.com:443 2>&1 | openssl x509 -noout -text | awk -F, -v OFS="\n" '/DNS:/{x=gsub(/ *DNS:/, ""); $1=$1; print $0}'

shadyabhi · 2020-04-10 06:56:51 88

From all PDF files in all subdirectories, extract two metadata fields (here: Creator and Producer) into a CSV table
This is sample output - yours may be different.
0

echo "File;Creator;Producer";find . -name '*.pdf' -print0 | while IFS= read -d $'\0' line;do echo -n "$line;";pdfinfo "$line"|perl -ne 'if(/^(Creator|Producer):\s*(.*)$/){print"$2";if ($1 eq "Producer"){exit}else{print";"}}';echo;done 2>/dev/null

langec · 2020-12-17 21:08:55 1412
Remove all the characters after last space per line including it

It his example removes ' dog', last space included. Show Sample Output
This is sample output - yours may be different.
```
The quick brown fox jumps over the lazy
```
0

echo 'The quick brown fox jumps over the lazy dog' | sed 's|$.*$ .*|\1|'

bugmenot · 2021-07-15 20:01:32 183
Clear Cached Memory on Ubuntu

Clear Cached Memory on Ubuntu based distributions, and also display memory status. Please do not use this on a production machine unless you really really know what you are doing. Echo 3 is a kinder way of purging the memory, you can also use 'echo 2' or 'echo 1' if #1 You know what you are doing, and #2 refer to number 1 :-)
This is sample output - yours may be different.
0

sudo free && sync && sudo echo 3 | sudo tee /proc/sys/vm/drop_caches

tg0000 · 2021-09-13 16:45:20 608
Infinite loop ssh

Useful when you wait for a server to boot up.
This is sample output - yours may be different.
0

while true; do ssh login@10.0.0.1; if [[ $? -ne 0 ]]; then echo "Nope, keep trying!"; fi; sleep 10; done

FluffyBrick · 2021-09-29 12:54:17 326
a pseudo-random coin flip in python
This is sample output - yours may be different.
-1

echo "import random; print(random.choice(['heads', 'tails']))" | python

ag3ntj0n · 2009-02-05 21:01:01 35
To generate the list of dates using bash shell
This is sample output - yours may be different.
-1

now=`date +"%Y/%m/%d" -d "04/02/2005"` ; end=`date +"%Y/%m/%d" -d "07/31/2005"`; while [ "$now" != "$end" ] ; do now=`date +"%Y/%m/%d" -d "$now + 1 day"`; echo "$now"; done

mnikhil · 2009-02-07 18:46:49 12
use perl instead of sed

Replace sed regular expressions with perl patterns on the command line. The sed equivalent is: echo "sed -e"|sed -e 's/sed -e/perl -pe/' Show Sample Output
This is sample output - yours may be different.
```
[root@bigdaddy ~]# echo "sed -e"|perl -pe 's/sed -e/perl -pe/'
perl -pe
```
-1

echo "sed -e"|perl -pe 's/sed -e/perl -pe/'

drossman · 2009-02-16 18:39:06 910
Random integer number between FLOOR and RANGE

This one-liner outputs a random number between the values given for FLOOR and RANGE. Show Sample Output
This is sample output - yours may be different.
```
6
```
-1

FLOOR=0; RANGE=10; number=0; while [ "$number" -le $FLOOR ]; do number=$RANDOM; let "number %= $RANGE"; done; echo $number

raphink · 2009-02-20 09:33:56 13
run a command repeatedly

This runs a command continuously, restarting it if it exits. Sort of a poor man's daemontools. Useful for running servers from the command line instead of inittab.
This is sample output - yours may be different.
-1

doloop() { DONT=/tmp/do-run-run-run; while true; do touch $DONT; (sleep 30; rm $DONT;) & $1 ; if [ -e $DONT ]; then echo restarting too fast; return ; fi ; done }

evil_otto · 2009-02-21 02:11:18 5
Easily create and share X screen shots (remote webserver version)

Here $HOME/shots must exist and have appropriate access rights and sitecopy must be correctly set up to upload new screen shots to the remote site. Example .sitecopyrc (for illustration purposes only) site shots server ftp.example.com username user password antabakadesuka local /home/penpen/shots remote public_html/shots permissions ignore The command uses scrot to create a screen shot, moves it to the screen shot directory, uploads it using screen uses xsel to copy the URL to the paste buffer (so that you can paste it with a middle click) and finally uses feh to display a preview of the screen shot. Note that $BASE stands for the base URL for the screen shots on the remote server, replace it by the actual location; in the example http://www.example.com/~user/shots would be fitting. Assign this command to a key combination or an icon in whatever panel you use. Show Sample Output
This is sample output - yours may be different.
```
sitecopy: Updating site `shots' (on ftp.example.com in public_html/shots/)
Uploading 2009-03-26-125223_1280x1024_scrot.png: [..............] done.
sitecopy: Update completed successfully.
```
-1

scrot -e 'mv $f \$HOME/shots/; sitecopy -u shots; echo "\$BASE/$f" | xsel -i; feh `xsel -o`'

penpen · 2009-03-26 12:08:39 4
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
‹ First < 49 50 51 52 53 > 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

statistics in one line

In this example, file contains five columns where first column is text. Variance is calculated for columns 2 - 5 by using perl module Statistics::Descriptive. There are many more statistical functions available in the module.

delete multiple files with spaces in filenames (with confirmation)

ls -Q will show the filenames in quotes. xargs -p rm will print all the filenames piped from ls -Q and ask for confirmation before deleting the files. without the -Q switch, if we have spaces in names, then the files won't be deleted.

Resize all JPEGs in a directory

This command requires the imagemagick libraries and will resize all files with the .jpg extension to a width of 1024 pixels and will keep the same proportions as the original image.

function to edit your history file

eh stands for Edit History . Frequently, I'll mistype a command, and then step back through my history and correct the command. As a result, both the correct and incorrect commands are in my history file. I wanted a simple way to remove the incorrect command so I don't run it by mistake. . When running this function, first the ~/bash_history file is updated, then you edit the file in vi, and then the saved history file is loaded back into memory for current usage. . while in vi, remember that `Shift-G` sends you to the bottom of the file, and `dd` removes a line. . this command is different than bash built-in `fc` because it does not run the command after editing.

Get AWS temporary credentials ready to export based on a MFA virtual appliance

You might want to secure your AWS operations requiring to use a MFA token. But then to use API or tools, you need to pass credentials generated with a MFA token. This commands asks you for the MFA code and retrieves these credentials using AWS Cli. To print the exports, you can use: `awk '{ print "export AWS_ACCESS_KEY_ID=\"" $1 "\"\n" "export AWS_SECRET_ACCESS_KEY=\"" $2 "\"\n" "export AWS_SESSION_TOKEN=\"" $3 "\"" }'` You must adapt the command line to include: * $MFA_IDis ARN of the virtual MFA or serial number of the physical one * TTL for the credentials

delete all bitbucket repos via rest API v2 (req: jq and curl)

bitbucket paginates at around 1360 characters, so if you have several pages of repos in git hub you can just add "?page={1..4}" the url used to get all the repos. you can also use -v for the deletion curl if you want to see the response from the server.

Debug how files are being accessed by a process

Instead of looking through `lsof` results, use inotifywait!

Search some text from all files inside a directory

copy with progress bar - rsync

-r for recursive (if you want to copy entire directories) src for the source file (or wildcards) dst for the destination --progress to show a progress bar

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"

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 using echo

Commands using echo (1,545) 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 using echo (1,545)

sorted by