Find a String inside Files
grep -rnw '/path/to/somewhere/' -e 'pattern'Find File in Folder Structure
find ./ -name card.php
Display Linux System Informations
uname
Display Kernel Releases Informations
uname -r
Display Systems uptime and load average
uptime
Show the systems hostname
hostname
Display IP-Adress of System
hostname -i
Show System Reboot History
last reboot
Display current date and time
date
Change or Query the system Clock
timedatectl
Display the current Calender Month and Day
cal
Display current logged in Users to the System
w
Display Informations about user who you are logged in as
whoami
Display Informations about a user
finger USERNAMEHERE
Change the current work directory
cd
See Bootup Messages
dmesg
Display informations about CPU
cat /proc/cpuinfo
Display Informations about Memory
cat /proc/meminfo
Display Informations about System Hardware Configuration
lshw
Display Block Devices Related Informations
lsblk
Display free and used Memory on the System (-m for MB)
free -m
Display PCI Devices in Diagram
lspsi -tv
Display USB Devices in Diagram
lsusb-tv
Display Hardware informations from BIOS
dmidecode
Display Informations about disk data (select right device)
hdparm -i /dev/xda
Start read speed test on device XDA
hdparm -tT /dev/xda
Test for corrupted Blocks on Disk
badblocks -s /dev/xda
Show Active Processs
ps
Searches for the ID of Process 'telnet'
ps aux | grep telnet
Displays Memory Map of Processes
pmap
Display all running processes like a task manager
top
Terminate a Process with an ID
kill IDHERE
Kill a processes named apache2
killall apache2
Visualize Processes in a Tree
pstree
Display Free Space on Mounted Systems
df -h
Display Free Inodes on Filesystems
df -i
Show Disk Partitions, sizes and types
fdisk -l
Display disk usage in the current directory in human readable format
du -sh
Display Details of the active user
id
Show the last login in the system
last
Show who is logged into the system now
who
Add the group admin
groupadd admin
Add the user sam
adduser sam
Deletes the user sam
deluser sam