Shell commands

1. ls
2. pwd
3. cal
4. time
5. date
6. ps -e
7. ps -ef
8. ps -eF
9. ps -ely
10. lsof -p $$
11. ALT .
12. CTRL l
13. CTRL u
14. CTRL k
15. CTRL c
16. CTRL z
17. CTRL R
18. CTRL T
    1. type -a->Find out if ls is builtin or external command
    2. yum search shell / apt-cache search shell
    3. cat /etc/shells--Pathnames of valid login shells
    4. which bash--to display the full path of (shell) commands
    5. chmod +x hello.sh---set execute permission
    6. ./hello.sh--------------Running Your Script
    7. #!--used in scripts to indicate an interpreter for execution under Linux OS
    8. #!/bin/bash-----------script starts with it
19. while loop

while [ condition ];

do

#put ur script here

done

vmstat 3

vmstat -m Memory Utilization

vmstat -a Active / Inactive Memory Pages

w username who is loges in for what

uptime

ps -Al/ps -elps -A/e

ps -AlF

ps -AlFH threads

ps -AlLm threads after processes

ps -ejH process tree

ps -eo euser,ruser,suser,fuser,f,comm,label security information

ps -U nandan -u nandan u : process run by nandan

ps -auxf | sort -nr -k 4 | head -10 top 10 memory consumer

ps -auxf | sort -nr -k 3 | head -10 top 10 cpu consumer

free displays the total amount of free and used physical and swap memory

iostat report statistics

mpstat -P ALL    activity of each processor