| Command | Description |
|---|---|
uname -a |
Displays all the system information like kernel, release date, operating system & processor |
| 'uptime` | Shows how long the system have been running and the system load |
hostname |
Shows the system hostname it can be used with hostname -I to show the ip address |
| 'last reboot` | Shows the system reboot history |
date |
Shows the date with timezone |
cal |
Shows the calender |
dmesg |
Print the kernel ring buffer with boot log |
cat /proc/cpuinfo |
Prints the cpu information for all the cores |
cat /proc/meminfo |
Prints the memory information |
cat /proc/interrupts |
Prints the number of interrupts per cpu & I/O device |
lsblk |
Lists the bloack devices |
free -m |
Display amount of free and used memory in the system in megabytes |
id |
Shows the active user id with login & group |
last |
Shows listing of last logged in users |
who |
Shows who is logged into the system |
ps |
Shows the current active process with the user, ps aux you can see all the process and filter it with grep as ps aux grep "bash" will show all the process with bash |
chmod 777 fileName |
Sets the rwx permission for owner, gotup, world |
chmod 755 fileName |
Sets the rwx permission for owner, rx for group and world |
chmod owner-user file |
Chnage the owner of the file |
| ` |