/bin

Binaries (User)

/boot

Static boot loader files

/etc

Host specific configs

/lib

Shared libraries and kernel modules

/sbin

Binaries (System/root)

/var

Varying files (e.g. Logs)

/usr

3rd party software

/proc

Pseudo file system

/sys

Pseudo file system

/mnt

Mountpoint for internal drives

/media

Mountpoint for external drives

/home

User homes

/run

PID files of running processes

cd

–

Navigate to last dir

~

Navigate to home

~username

Navigate to home of specified user

pwd

Print working dir

ls

Print dir content

-l

Format as list

-a

Show hidden items (-A without . and ..)

-r

Invert order

-R

Recurse

-S

Sort by size

-t

Sort by date modified

mkdir

-p

Create dir with parents

cp

-r

Copy dir

rmdir

-p

Remove dir and empty parents

rm

-rf

Remove dir recursively, -f without confirmation

mv

Move recursively

find

-iname pattern

Search dir/file case-insensitive

-mmin n

Last modified n minutes ago

-mtime n

Last modified n days ago

-regex pattern

Path matches pattern

-size n[kMG]

By file size (-n less than; +n greater than)

! searchparams

Invert search

cat

file

Print content

tac

file

Print content inverted

sort

file

Print sorted

file -r -u

Print sorted descending without dublicates

head

-n10 file

Print lines 5-10

tail

-f file

Print new lines automatically

cut

-f -4,7-10,12,15- file

Print selected fields (tab delimited)

-c -4,7-10,12,15- file

Print selected characters positions

-f 2,4 -d, –output-delimiter=$’\t’ file

Change delimiter (but use tab for output)

uniq

file

Hide consecutive identical lines

file -c

Show consecutive identical line count

file -u

Hide consecutive identical lines

file

file

Get file type

wc

file

Count Lines, Words, Chars (Bytes)

tar

cfv archiv.tar file1 file2

Create archive / add or overwrite content

tfv archiv.tar

Show content

xf archiv.tar [-C ~/extracted]

Extract (and decompress) archive (to ~ / extracted)

cfvj archiv.tar.bz2 file

Create bzip2 compressed archive

cfvz archiv.tar.gz file

Create gzip compressed archive

cfa archiv.tar.[komp] file

create compressed archive (auto type based on name)

bzip2

file1 file2

Dateien (einzeln) komprimieren

-d file1 file2

Compress files (one at a time)

gzip

file1 file2

Dateien (einzeln) komprimieren

-d file1 file2

Decompress files

fdisk

-l

List physical disks and partitions

/dev/sdb
n

Create new partition

/dev/sdb
t
8e

Change partition type to Linux LVM

mkfs.xfs

/dev/myVG/myVol

Format LV with XFS

mkfs.ext4

-f /dev/myVG/myVol

Format LV with EXT4 (overwrite)

blkid

/dev/myVG/myVol

Show UUID and formatting of volume

mount

Show current mounted file systems

-t ext4 /dev/myVG/myVol /mountpoint

Mount LV to /mountpoint

-a

Mount as configured in /etc/fstab

umount

Unmount a file system

/dev/myVG/myVol

Unmount LV from /mountpoint

/mountpoint

Unmount LV from /mountpoint

df

–

Show disk usage

xfs_growfs

/dev/myVG/myVol

Resize xfs filesystem

resize2fs

/dev/myVG/myVol

Resize ext3/4 filesystem

<command>

–help

Help of current command (not standardized)

-h

-?

man

<command>

Manual page of command

-k keyword

Search command by keyword (oder apropos)

alias

Show aliases

name=’befehl’

Create alias

?

Any single character

*

Any characters

[ac-e]

1 character in enum

[!ac-e]

1 character not in enum

.

Any single character

[ac-e]

1 character in enum

[^ac-e]

1 character not in enum

^

Start of string

$

End of string

\d

Digit

\D

Not a digit

\s

Whitespace

\S

Not a Whitespace

\<

Start of word

\>

End of word

pattern?

Quantifier 0 or 1

pattern*

Quantifier 0..n

pattern+

Quantifier 1..n

pattern{x}

Quantifier exactly x

pattern{x,}

Quantifier x..n

pattern{x,y}

Quantifier x..y

pattern{,y}

Quantifier 0..y

grep

pattern file

Extended Regex

-E pattern file

Extended Regex

-v pattern file

Invert match

-w pattern file

Word match

-i pattern file

Ignore case

> file or 1> file

STDOUT to file

< file

Datei to STDIN

2> file

STDERR to file

2>&1

STDERR to same target as STDOUT

> file 2>&1

STDOUT and STDERR to file

q

Quit

R

Refresh content

F

Auto scroll

g number

Go to line

m lowercaseLetter

Mark line

‘ lowercaseLetter

Go to mark

/pattern

Search forward

?pattern

Search backward

n

Next search result

N

Last search result

ESC u

Remove highlighting from search

i

insert before cursor

a

insert after cursor

A

insert at end of line

o

new line below

O

new line above

u

undo

.

repeat last command

yy

copy line

5yy

copy 5 lines

p

paste below

P

paste above

x

delete character

5x

delete 5 characters

dd

delete line

5dd

delete 5 lines

:10,20d

delete lines 10-20

d0

delete to line begin

d$

delete to line end

5G

go to line 5

H

go to top of screen

M

go to middle of screen

L

go to end of screen

5w

move over 7 words

5b

move back 5 words

/foo

search forward

?foo

search backwards

n

repeat search

:w

save

:q

close

:wq

save and close

:q!

close without saving

:!command

run bash command

:r foo

read file foo into this file

<1000

system account

>1000

user account

hfict

x

1000

1000

/home/hfict

/bin/bash

wheel

x

10

hfict,user2

hfict

[hash]

17803

0

99999

7

id

username

Show a user’s ID and groups

who

Show logged in users

last

Show last logins

lastb

Show last failed logins

sudo

-u user command

Execute command with user rights (default is root)

-i or su –

Shell with root rights

su

Shell as root (non-login shell)

–

Shell as root (login shell)

– user

Shell as user

useradd

-u 2101 -g primarygroup -c comment username

Create user (without -g, new group will be created)

usermod

-G group1, group2

Define (overwrite) secondary groups

-ag group, group2

Add secondary groups

-l username

Change username

-L

Lock Account

-U

Unlock Account

-s shellpath

Change shell

userdel

-r username

Delete user including home and mail spool

passwd

username

Change password (interactive)

groupadd

groupname

Create group (optionally set GID with -g)

groupdel

groupname

Delete group

r

4

read

w

2

write

x

1

execute

t / T

1

Sticky Bit

Others can’t delete content (only applicable for directories)

s / S

2

SGID-Bit

File: run with permissions of Group
Dir: New elements inherit Group

s / S

4

SUID-Bit

File is run with permissions of User (only applicable for files)

chmod

-R [uog] dirname

Set permissions recursively using binary flags

+[suog] filename

Add permissions using binary flags

-[suog] filename

Remove permissions using binary flags

u+x filename

Add execute permission for User

g+wx filename

Add write and execute permissions for Group

o-r filename

Remove read permission for Others

chown

-R user:group filename

Change owner (User & Group) recursively

user filename

Change owner (User)

:group filename

Change owner (Group)

chgroup

group filename

Change owner (Group)

PermitRootLogin

no

Deny root to login via SSH

yes

Allow root to login via SSH

without-password

Allow only with private/public key auth

AllowUsers

user1 user2

Allow only user1 and user2

DenyUsers

user1 user2

Allow all users but user1 and user2

AllowGroups

group1 group2

Allow only users from specified groups

DenyGroups

group1 group2

Allow all users but those in specified groups

rpm -q cronie

Check if package is installed

systemctl status crond.service

Check if service is running

crontab -l

List current users crontab

crontab -e

Edit current users crontab

crontab -e -u username

Edit specific users crontab

crontab -r

Remove current users crontab

rpm -i rpmfile|rpmurl

Install package

rpm -e packagename

Uninstall package

rpm -q packagename

Check if package is installed

rpm -ql packagename

List files in a package

rpm -qa

List all installed packages

rpm -qf /path/to/file

Get package that installed the file

rpm -qf $(which <exe>)

Get package that installed the executable

rpm -V packagename

Validate installed package

yum install packagename [-y]

Install package (-y no confirm message)

yum remove packagename

Uninstall package

yum update

Update all installed packages

yum update packagename

Update specific package

yum update pattern*

Update packages using wildcard

yum info packagename

Get detailed info about package

yum list packagename

List installed and available packages

yum search searchstring

search for a package (name & summary)

yum search all searchstring

search for a package (all infos)

yum deplist packagename

List dependencies of a package

yum reinstall packagename

Reinstall (corrupted) package

yumdownloader –resolve packagename

Download rpm package with dependencies