topic Re: using variables in case command in Operating System - HP-UX

using variables in case command

gary phipps — Tue, 02 Apr 2002 15:43:55 GMT

I've written a script similar to the following...

case $var1 in
$var2 )
do stuff ;;
* )
do nothing ;;
esac

...where $var2 = "001|002|003" but $var2 is not being translated correctly, or at least how I thought it would be.
If I set $var2 to be a single value (without the pipes) it works fine.

Can anyone advise on the correct syntax?

Re: using variables in case command

hpuxrox — Tue, 02 Apr 2002 15:53:34 GMT

Try putting 001|002|003 in single ' quotes.
$var2 = '001|002|003'

Re: using variables in case command

Mark Greene_1 — Tue, 02 Apr 2002 15:53:40 GMT

the pipe is just another character to the shell, not a delimeter. You can use tabs, or change the FS (field separator) variable to the pipe:

OLD_FS=$FS
FS="|"
CASE
...
ESAC
FS=$OLD_FS

HTH
mark

Re: using variables in case command

S.K. Chan — Tue, 02 Apr 2002 15:54:51 GMT

The "|" is being translated as logical or in the case statement. Try this instead ..

case $var1 in
"$var2" )
do stuff ;;
* )
do nothing ;;
esac

Re: using variables in case command

S.K. Chan — Tue, 02 Apr 2002 16:12:28 GMT

I totally misunderstood your q, sorry .. why not use pattern matching in the case statement ..?

case $var1 in
00[1-3] )
do stuff ;;
* )
do nothing ;;
esac

Re: using variables in case command

SHABU KHAN — Tue, 02 Apr 2002 19:48:34 GMT

Gary,

Try escaping the pipe with backslash like this:

...where $var2 = "001\|002\|003"

and then: double quotes var2

case $var1 in
"${var2}" )
do stuff ;;
* )
do nothing ;;
esac

-Shabu

Re: using variables in case command

Wodisch — Tue, 02 Apr 2002 22:02:42 GMT

Hi,

you should always quote substitution, hence:
case "$var" in
"$var2) ... ;;
esac

Just my $0.02,
Wodisch

Re: using variables in case command

Magdi KAMAL — Wed, 03 Apr 2002 10:01:57 GMT

Hi Gary,

You have to put the exact "Constant" into the value of case. You are NOT allowed to do it as you mentioned :

case $var1 in
$var2 )
do stuff ;;
* )
do nothing ;;
esac

Syntax would be :

case $var1 in
'001|002|003')
do stuff ;;
* )
do nothing ;;
esac

No varaibles are allowed to be used in the constant expressions.

Magdi

Re: using variables in case command

gary phipps — Wed, 03 Apr 2002 10:24:09 GMT

Hi folks,

thanks for all the input. I tried all of the above but unfortunately none of them worked. I'll try various combinations of your suggestions and let you know what happens.

Gary.

Re: using variables in case command

Mark Greene_1 — Thu, 04 Apr 2002 20:46:53 GMT

how are your populating var1 prior to doing the case?

mark

Re: using variables in case command

Mark Fenton — Fri, 05 Apr 2002 01:59:04 GMT

Gary,

The syntax you need will be something like:

var1=$1
var2='00[1-3]'

case $var1 in
$var2) commands ;;
*) other commands ;;
esac

The issue is how you are assigning your variables. If you know what the allowable range of values for var2 is ahead of time, you can use the above style of assignment to test.

Mayhap if you could post how you're deriving var1 and var2 it would be helpful (if the above isn't what you're after).

Mark