Important linux commands

1. display the utilization of each CPU induvisualy.
     > mpstat -P ALL
2. top 10 process which consumes cpu.
     > ps -eo pcpc,pid,user,args | sort -k 1 -r | head -10
3. display memory datails.
     >cat /proc/meminfo
4. display memory usage.
     > free -m
     > vmstat
5. display number of cpu's.
     >cat /proc/cpuinfo | grep processor | wc -l
6. display shared memory parameters.
     > ipcs -m
7. display disk activity.
    > iostat
8. display all users loged into the system.
    > w
9. display how long the system is been running.
    >uptime
10. display which shell is used.
    >ps -p $$
    >echo $shell
11. list all users.
    > cat /etc/passwds
12. version of kernael.
   > cat /proc/version
13. to know swap allocated.
    > cat /proc/swaps
14. shells available in system.
    > cat /etc/shells