check if environment variable is set

[gotchausa]

How I do the following in Solaris:
1. Check to see of environ. variable $TAPE is set.
2. If it is not, then set it to /dev/rmt/0n
3. If it is set, then dont do anything.

 

[vgersh99]

#!/bin/ksh

if [ ! -n "${TAPE}" ]; then
TAPE='/dev/rmt/0n'
fi;


OR alternatively [in ksh]:

${TAPE:=/dev/rmt/0n}

 

[gotchausa]

I have tried these methods within my script but when I exit the script and do:

echo $TAPE

I dont get /dev/rmt/0n as expected. I get whatever it was before (e.e emty output if it was not set).

 

[olded]

mpv:

When you execute a script it spawns a new shell, and shell variables defined in the child process are not automatically passed back to the parent. If your script is called myscript.ss and runs in ksh and sh, you need to use the dot operator:

. myscript.ss # space after the "."

This was covered extensively in this forum under thread:

thread822-255445

Regards,

Ed

 

[gotchausa]

I got it! Thanks.