Useful Linux Commands-1

I compiled useful linux commands

System

CommandDescription
uname -aDisplays system information
uname -rDisplays kernel version
uptimeGives a one-line display the current time, how long the system has been running, how many users are currently logged on, the system load averages for the past 1, 5, and 15 minutes
hostnameDisplays the system host name
last rebootDisplay last reboot times
dateDisplays the system date and time
calDisplay the calendar for this month, with today highlighted
wDisplays a list of logged on users and their processes as shown below
whoamiDisplays the name of the user who runs the command
finger itechDisplay information about the user itech

 

Hardware

CommandDescription
dmesgDisplays the kernel messages
cat /proc/cpuinfoDisplays information about the processor
cat /proc/meminfoDisplays information about memory (RAM)
cat /proc/interruptsDisplays CPU kernel system interrupt list
lshwDispays the system’s hardware configuration information
lsblkDisplay the disk partition table
free -mDisplay the amount of memory in megabytes
lspci -tvLists PCI devices
lsusb -tvLists USB devices
dmidecodeDisplays BIOS hardware information
hdparm -i /dev/sdaInforms about disk
hdparm -tT /dev/sdaDisplays the reading speed test for the used disk
badblocks -s /dev/sdaChecks HDD for bad sectors

 

Users

CommandDescription
idDisplays the user id information
lastDisplays a list of all users logged in (and out)  since  that  file was created
whoPrint information about users who are currently logged in
groupaddAdds a new group in the system
useraddAdds a new user in the sysem
userdelDeletes a user account and all associated files
usermodModifies a user account