Bash Commands
uname -a |
Show system and kernel |
head -n1 /etc/issue |
Show distribution |
mount |
Show mounted filesystems |
date |
Show system date |
uptime |
Show uptime |
whoami |
Show your username |
man command |
Show manual for command |
Bash Shortcuts
CTRL-c |
Stop current command |
CTRL-z |
Sleep program |
CTRL-a |
Go to start of line |
CTRL-e |
Go to end of line |
CTRL-u |
Cut from start of line |
CTRL-k |
Cut to end of line |
CTRL-r |
Search history |
!! |
Repeat last command |
!abc |
Run last command starting with abc |
!abc:p |
Print last command starting with abc |
!$ |
Last argument of previous command |
ALT-. |
Last argument of previous command |
!* |
All arguments of previous command |
^abc^123 |
Run previous command, replacing abc with 123 |
Bash Variables
env |
Show environment variables |
echo $NAME |
value of $NAME variable |
export NAME=value |
Set $NAME to value |
$PATH |
Executable search path |
$HOME |
Home directory |
$SHELL |
Current shell |
IO Redirection
cmd < file
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cmd1 <(cmd2)
- of cmd2 as file input to cmd1
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cmd > file
- Standard (stdout) of cmd to file
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cmd > /dev/null
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cmd >> file
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cmd 2> file
- Error (stderr) of cmd to file
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cmd 1>&2
- stdout to same place as stderr
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cmd 2>&1
- stderr to same place as stdout
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cmd &> file
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cmd refers to a command.
Command Lists
cmd1 ; cmd2
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cmd1 && cmd2
- Run cmd2 if cmd1 is successful
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cmd1 || cmd2
- Run cmd2 if cmd1 is not successful
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cmd &
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Nano Shortcuts
Files |
Ctrl-R |
Read file |
Ctrl-O |
Save file |
Ctrl-X |
Close file |
Cut and Paste |
ALT-A |
Start marking text |
CTRL-K |
Cut marked text or line |
CTRL-U |
Paste text |
Navigate File |
ALT-/ |
End of file |
CTRL-A |
Beginning of line |
CTRL-E |
End of line |
CTRL-C |
Show line number |
CTRL-_ |
Go to line number |
Search File |
CTRL-W |
Find |
ALT-W |
Find next |
CTRL-\ |
Search and replace |
More nano info at:
http://www.nano-editor.org/docs.php
Process Management
ps |
Show snapshot of processes |
top |
Show real time processes |
kill pid |
Kill process with id pid |
pkill name |
Kill process with name name |
killall name |
Kill all processes with names beginning name |
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Screen Shortcuts
screen
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screen -r
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screen -list
- Show your current screen sessions.
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CTRL-A
- Activate commands for screen.
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CTRL-A c
- Create a new instance of terminal.
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CTRL-A n
- Go to the next instance of terminal.
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CTRL-A p
- Go to the previous instance of terminal.
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CTRL-A "
- Show current instances of terminals.
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CTRL-A A
- Rename the current instance.
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More screen info at:
http://www.gnu.org/software/screen/
ls Options
-a |
Show all (including hidden) |
-R |
Recursive list |
-r |
Reverse order |
-t |
Sort by last modified |
-S |
Sort by file size |
-l |
Long listing format |
-1 |
One file per line |
-m |
Comma-separated |
-Q |
Quoted |
Search Files
grep pattern files |
Search for pattern in files |
grep -i |
Case insensitive search |
grep -r |
Recursive search |
grep -v |
Inverted search |
grep -o |
Show matched part of file only |
find /dir/ -name name* |
Find files starting with name in dir |
find /dir/ -user name |
Find files owned by name in dir |
find /dir/ -mmin num |
Find files modifed less than num minutes ago in dir |
whereis command |
Find binary / source / manual for command |
locate file |
Find file (quick search of system index) |
Directory Operations
pwd |
Show current directory |
mkdir dir |
Make directory dir |
cd dir |
Change directory to dir |
cd .. |
Go up a directory |
ls |
List files |
File Operations
touch file1
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cat file1 file2
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less file1
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file file1
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cp file1 file2
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mv file1 file2
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rm file1
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head file1
- Show first 10 lines of file1
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tail file1
- Show last 10 lines of file1
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tail -f file1
- last lines of file1 as it changes
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File Permissions
chmod 775 file
- Change mode of file to 775
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chmod -R 600 folder
- Recursively chmod folder to 600
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chown user:group file
- Change file owner to user and group to group
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File Permission Numbers
The first digit is the owner permission, the second the group and the third for everyone. |
Calculate each of the three permission digits by adding the numeric values of the permissions below. |
4 |
read (r) |
2 |
write (w) |
1 |
execute (x) |
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