Shell Programming and Scripting

So I came across a minor issue here, and was hoping anyone could help me.

I'm on Unix SunOS, 5.10 as well as Linux 2.6.32
So everything I do has to work on both (fun ..)

Anyway, I have a few scripts, which handle some temporary files, I dropped in some basic trap commands in order to clean things up when it exits:

Code:

TMPF=`mktemp -p ${TEMP_DIR}`
trap "exec 5>&-;rm -f ${TMPF};" EXIT

This (seems to) work fine, however, I run into a small issue when I call one script from the other

So I have the above code in 2 scripts, and in the first I call the 2nd. They each have their own temp file, both of which I want cleaned up when that particular script exits.

ie

Code:

> cat script_1.ksh
#!/usr/bin/ksh
TMPF=`mktemp -p ${TEMP_DIR}`
trap "exec 5>&-;rm -f ${TMPF};" EXIT
 
# do something
 
./script_2.ksh
 
# do something else
exit 0

and

Code:

> cat script_2.ksh
#!/user/bin/ksh
TMPF=`mktemp -p ${TEMP_DIR}`
trap "exec 5>&-;rm -f ${TMPF};" EXIT
 
# do something ...
exit 0

However, I'm noticing the the file from script_1.ksh sticks around, and isn't being cleaned up. I'm assuming it's because of the similar declaration in script_2 is "clobbering" it ... however, I'm not 100% sure how to work around this?
I'm tempted to change the line:

Code:

 
trap "exec 5>&-;rm -f ${TMPF};" EXIT

to:

Code:

 
trap "exec 6>&-;rm -f ${TMPF};" EXIT

However, even if that works [edit] it doesn't - tried it - found confirmation that it's the subsequent trap clobbering the existing trap[/edit], I'm not sure that's the "correct" solution.

Any suggestions?

Redeclare the trap in #1 right after #2 returns.

From POSIX on assigning traps:

Code:

If the assignment precedes a utility name in a command, the export attribute shall not persist in the 

current execution environment after the utility completes, with the exception that preceding one of the special 

built-in utilities causes the export attribute to persist after the built-in has completed.

(red emphasis mine)

A "utility" can be executing a subprocess or "shelling out'.

Jim, doesn't your quote rather mean a prefixed assignment like

Code:

PATH=/bin:/usr/bin uname

?
--
For me this looks like bug. Running annother program, even another shell, should not obscure the current signals.

Which version of ksh are you using?

I listed my O/S version above - how do I check the specific version of ksh?

In Korn shell you might want to use "trap 0" to do end processing (such as removing temporary files). It is a virtual signal and the trap code is executed every time the script exits, regardless of how the exit is done.

I hope this helps.

bakunin

Sorry, am I missing something?
I thought:

Code:

trap "<stuff>" 0

and

Code:

trap "<stuff>" EXIT

where essentially identical?
In anycase, wouldn't they both get nuked when I called the next shell anyway? (according to the docs?) [edit]correction: meant to imply when the next TRAP command is issued - within the next shell - sorry [/edit]

Sorry, I'm not sure what you're trying to say here that I haven't already tried?