After my blog post about command line one-liners, many people want to contribute with their own commands. This is the place to do it, pull requests are welcome!
Run the last command
$ !!
Run the last command as root
$ sudo !!
Create a script of the last executed command
$ echo "!!" > script.sh
Reuse all parameter of the previous command line
$ echo cd .
$ !*
Run the last command with some argument
$ echo a b c d e
$ echo !!:2
$ echo !!:3-$
Insert the last argument of the previous command
$ cp script.sh /usr/bin/
$ cd !$
$ cd <ESC> .
$ cd <ALT> .
Runs previous command but replacing
$ echo no typos
$ ^typos^errors
Escape any command aliases
$ alias ls="ls -a"
$ \ls
Quickly rename a file
$ mv filename.{old,new}
$ mv filename.{png,jpg}
Create a quick back-up copy of a file
$ cp file.txt{,.bak}
Run a command from the history
$ history
...
1225 ls -l
1226 git status
1227 history
$ !-3
$ !1225
Search the history for the most recent command beginning with 'text'
$ !text
Search the history for the most recent command containing 'text'
$ <ctrl-r>text
List of commands you use most often
$ history | awk '{print $2}' | sort | uniq -c | sort -rn | head
Execute a command without saving it in the history
$ <space>command
Make directory including intermediate directories
$ mkdir -p a/long/directory/path
Create a directory and change into it
$ mkdir dir && cd $_
Change to the previous working directory
$ cd -
Jump to a directory. Execute a command in a subshell. Jump back to current directory
$ (cd /tmp && ls)
Create simple text file from command line
$ cat > file.txt
{your text here}
{your text here}
<ctrl-d>
Create simple text file from command line or script (EOF is just a token, can be any word)
$ cat > file.txt << EOF
{your text here}
{your text here}
EOF
Empty a file from command line (usefull to truncate log file from running processes)
$ > file.txt
Empty a file from command line or script
$ cat /dev/null > file.txt
Show PATH in a human-readable way
$ echo $PATH | tr ':' '\n'
$ tr ':' '\n' <<< $PATH
Make 'less' behave like 'tail -f'
$ less +F somelogfile
Display line numbers in a file
$ cat -n file
$ less -N file
Redirect standard input to a file. Print it to standard output
$ command | tee file.txt | less
┌─────────┐ ┌─────────┐ ┌─────────┐
│ command │─▸│ tee │─▸│ stdout │
└─────────┘ └────┬────┘ └─────────┘
│
▾
┌───────────┐
│ file │
└───────────┘
Search for a string inside all files in the current directory
$ grep -RnsI --color=auto <pattern> *
Beyond grep
_ /|
\'o.O'
=(___)=
U ack!
$ ack <pattern>
Recursively remove all empty directories
$ find . -type d -empty -delete
Count your commits
$ git shortlog -sn
Serve current directory tree at http://$HOSTNAME:8000/
$ python -m SimpleHTTPServer
$ ruby -run -e httpd . -p 8000
Share a file between two computers
receiver $ nc -l 5566 > data-dump.sql
sender $ nc <receiver-ip-address> 5566 < data-dump.sql
Share a BIG file between two computers and show progress bar
receiver $ nc -l 5566 > big-file.iso
sender $ pv big-file.iso | nc <receiver-ip-address> 5566
Transfer a folder between two computers
receiver $ nc -l 5566 | tar -zxv
sender $ tar -zcv <folder> | nc -w1 <receiver-ip-address> 5566
Create an ISO image from a directory
$ mkisofs -o my-backup.iso /a/directory/
Download an entire website
$ wget -m http://website.com
Clear the terminal screen
<ctrl-l>
Salvage a borked terminal
$ reset
Close shell keeping all subprocess running
$ disown -a && exit
Run a command immune to hangups
$ nohup command &
Attach screen over ssh
$ ssh user@host -t screen -r
Compare a remote file with a local file
$ ssh user@host cat /path/to/remotefile | diff /path/to/localfile -
Get your public IP address
$ curl ifconfig.me
Set audible alarm when an IP address comes online
$ ping -a IP_address
List programs with open ports and connections
$ lsof -i
Check which process is listening on a specific port
$ netstat -nlp | grep 8080
$ netstat -nlp tcp | grep 8080 (BSD)
Check which process is modifying a certain directory or file
$ auditctl -w /path/to/directory -p war
# see results with:
$ ausearch -f /path/to/directory
Currently mounted filesystems in nice layout
$ mount | column -t
Hierarchy of available block devices
$ lsblk
Display free disk space
$ df -h
Display disk usage statistics for the current directory
$ du -sh *
Display 10 biggest files/folders for the current directory
$ du -s * | sort -nr | head
Create a zip archive of a directory
$ zip -r archive.zip directory
Extract compressed archive
$ unzip archive.zip
Execute a command at a given time
$ echo "ls -l" | at midnight
Simple stopwatch
$ time read
<ctrl-d>
Put a console clock in top right corner
$ while sleep 1;do tput sc;tput cup 0 $(($(tput cols)-29));date;tput rc;done &
Display the top ten running processes. (Sorted by memory usage)
$ ps aux | sort -nk +4 | tail
Kill all Ruby processes
$ ps aux | grep ruby | awk '{ print $2 }' | xargs kill -9
$ ps aux | awk '/ruby/ && ! /awk/ { system("kill -9 "$2) }'
$ pkill -f ruby
$ killall -9 ruby
32 bits or 64 bits?
$ getconf LONG_BIT
Displays a calendar
$ cal 12 1984
What day is today?
$ cal | sed "s/.*/ & /;s/ $(date +%d) / [] /"
$ cal | sed "s/.*/ & /;s/ $(date +%d) / $(printf '\e[0;31m[]\e[0m') /"
What date was it yesterday or will it be tomorrow, etc...
$ date -d yesterday
$ date -d tomorrow +%Y-%m-%d
$ date -d "7 days ago" +%Y-%m-%d
$ date -j -v-1d (BSD)
Show File System Hierarchy
$ man hier
Quick access to the ascii table
$ man ascii
Shutdown the system at a given time
$ shutdown -h now
$ shutdown -h 22:49
Russian Roulette in Bash
$ [ $[ $RANDOM % 6 ] == 0 ] && echo "You die" || echo "You live"
Watch Star Wars via telnet
$ telnet towel.blinkenlights.nl