Shell Syntax format

Shell Syntax format

If statement

If condition

Then

Command sequence

Fi

If condition

Then

Command sequence

Else

Command sequence

Fi

If condition

Then

Command sequence

Elif conditions

Then

Command sequence

Elif conditions

Then

Command sequence

Else

Command sequence

Fi

eg

#!/bin/bash

Read-p "Enter a password:" Password

If ["$password" = "pass"]; Then

echo "OK"

Else

echo "Error"

Fi

Case $ variable name in

Mode 1)

Command sequence

;;

Mode 2)

Command sequence

;;

Mode N)

Command sequence

;;

*)

Esac

Case $ variable name in

Mode 1| Mode 2)

Command sequence

;;

Mode 3| Mode 4)

Command sequence

;;

Mode 5| mode 6)

Command sequence

;;

*)

Esac

eg

#!/bin/bash

Case $ in

[a-z]| [A-z])

echo "character"

;;

[[:d Igit:]])

echo "Number"

;;

*)

echo "Eorror"

Esac

For variable in value 1 value 2 ... Value n

Do

Command sequence

Done

For (initialize variable value; end loop condition; operation))

Do

Command sequence

Done

eg

#!/bin/bash

For i in {1..10}

Do

Echo $i

Done

while [condition]

Do

Command sequence

Done

While Read-r line

Do

Command sequence

Done < file

eg

#!/bin/bash

File=/etc/sysconfig/network-scripts/ifcfg-eth0

While Read-r line

Do

Echo $line

Done < $file

Shell Syntax format