Commands using echo sorted by votes

Commands using echo (1,545)

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Python version to a file

This command sent the Python version to a file. This is intended to be used in scripts. For some reason, simple redirections didn't work with "python -V" Show Sample Output
This is sample output - yours may be different.
```
cat file
Python 2.6.3
```
0

echo "$(python -V 2>&1)" > file

x3mboy · 2018-11-06 20:52:49 448
Generate a sequence of numbers.
This is sample output - yours may be different.
0

echo {1..99}

wolfpup · 2018-11-11 01:04:22 601
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 14:38:05 902
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 12:30:19 206
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 16:26:48 323
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 09:15:37 455
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 16:50:12 713
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 10:49:58 106

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 1264
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 20:01:32 174
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 16:45:20 584
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 12:54:17 322
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 32
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 18:39:06 867
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
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Press ctrl+r in a bash shell and type a few letters of a previous command

In the sample output, I pressed ctrl+r and typed the letters las. I can't imagine how much typing this has saved me.

Tells the shell you are using

External IP (raw data)

can be used in script like : echo $(wget -qO- http://utils.admin-linux.fr/ip.php)

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"

Ultra fast public IP address lookup using Cloudflare's 1.1.1.1

Show numerical values for each of the 256 colors in ZSH

This will show a numerical value for each of the 256 colors in ZSH. Everything in the command is a ZSH builtin, so it should run on any platform where ZSH is installed. Prints one color per line. If someone is interested in formatting the output, paste the alternative.

Get the current svn branch/tag (Good for PS1/PROMPT_COMMAND cases)

uses just one sed

Converts to PDF all the OpenOffice.org files in the directory

Requieres unoconv (debian package)

list files recursively by size

Number of CPU's in a system

this works for a Linux based system, other UNIX systems may have other way(s) to check the number of CPUs.

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Commands using echo (1,545)

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