Understanding Code in IF LOOP

Ariean · #1 (**permalink**) 06-25-2009

Hello All,

I would like to know and understand the difference between the below 3 IF loops and also if possible what are the different other parameters i could use other than those mentioed in the below lF LOOP conditions, appreciate your help.

Quote:

if [ $? -ne 0 ] ; then
...some statements
fi

Quote:

if [ $? -eq 0 ] ; then
...some statements
fi

Quote:

if [ $# -eq 3 ] ;then
...some statements
fi

Thanks,
Sam.

fpmurphy · #2 (**permalink**) 06-25-2009

First of all, it is not an "IF LOOP".

The first if statement will execute if exit code from the previous command was not 0.
The second if statement will execute if the exist code from the previous command was 0
The third if statement will execute if the number of positional parameters is 3.

To learn more, read the man page of your shell.

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