topic Linux shell scripting in Operating System - Linux

Linux shell scripting

Ragni Singh — Fri, 15 Jul 2005 05:59:06 GMT

Hello, all, I have this script with a whole bunch of "if" statements.

How is it possible to make it into a nested "if' statement or if there is such a thing.

Does anyone else have any idea how to make this a better script?

Re: Linux shell scripting

Stuart Browne — Fri, 15 Jul 2005 06:05:41 GMT

Well, nested is exactally as you think it should be:

if [ condition ]
then
if [ nextcondition ]
then
if [ anothercondition ]
then
code
fi
fi
fi

Or in-line:

if [ condition -a nextcondition -a anothercondition ]
then
code
fi

Or perhaps you'd prefer a case:

case value in
value1) code ;;
value2) code ;;
*) defaultcode ;;
esac

Re: Linux shell scripting

Gopi Sekar — Fri, 15 Jul 2005 06:25:34 GMT

case is ideal for these kind of situation.

if that is not possible you can use if-elif-fi

eg:
if
then

elif
then

else

fi

Regards,
Gopi

Re: Linux shell scripting

Steve_160 — Sat, 16 Jul 2005 01:58:10 GMT

Maybe a "case" statement might work better for you. It's hard to say without seeing the script.

Re: Linux shell scripting

Steve_160 — Sat, 16 Jul 2005 02:01:06 GMT

Oops. Sorry, Gopi. :-/ I didn't mean to repeat what you said. When the question first came up on the screen there were no replies shown.

Re: Linux shell scripting

Gopi Sekar — Sat, 16 Jul 2005 02:50:29 GMT

steve,
for that matter i indeed repeated stuart's suggestion :)

if you are not able to see the replies, then raise it as an issue to moderators

Re: Linux shell scripting

Ross Minkov — Sat, 16 Jul 2005 07:28:35 GMT

See the Advanced Bash-Scripting Guide at http://www.tldp.org/LDP/abs/html/testconstructs.html for more examples.

-Ross