Coredump in kornshell but not in possix?

[Danny Engelbarts]

Hi,

I noticed something weird in the kornshell, the attached script will generate a memory fault (SIGSEGV) when executed using /usr/bin/ksh but when the first line is changed to #!/usr/bin/sh it will run without any problems! Does anyone have a clue what's going on? (Seems like a bug to me ...)

Greetz, Danny

[Dave Kelly_1]

I've just run your script on my 10.20 system without a problem.

What OS do you have ? Patches ?

Can you also supply the stderr output seeing as you included set -x in the script. It would be good to see exactly where the SIGSEGV is occurring.

[Danny Engelbarts]

Hey Dave,

Here's some more info (attachment), although i did include the set -x there is no debug output?
I ran the original on a 10.10 system, i've tried on 10.20 as well and i get the same error.

Greetz, Danny.

[Rainer_1 · Accepted solution]

don't know why but the problem points to the shift statement within the while getopts ... do ... done loop
Remove the shift line and add after the loop

shift $(($OPTIND -1))

then the script runs at both shells

[Danny Engelbarts]

Yep! That's it ... still wondering why now ;o)

Thanks! Danny.

[Carlos Fernandez Riera]

Your problem is you are making too shifts ( more than arguments).

insert echo $# $* before shift and run.

See man getopts:

thera are an example that use shift out of loop and ussing $OPTIND.


HTH

[Danny Engelbarts]

Hmmm,

If i read the manual correctly getopts should only walk through the "legal options" i.e. all options with either a preceding - or + sign. But it seems the implementation in the kornshell walks through the other options as well?

Danny.

[Carlos Fernandez Riera]

I understand that getopts may search over all args to find all options.

For your script perhaps you will prefer:

DiffTime -h -s time -e time

and getopt hs:e:.

See man 3c getopt too.

[CHRIS_ANORUO]

Hi Danny,

Check with this command "swlist -l fileset|grep sh" to see if you have patch PHKL_19762 installed on your server.
The patch is a fix for debugging shared lib gets SIGSEGV problem.

[Bill Hassell]

Just a note about debugging (tracing with set -x): the trace output will go to stderr. So to trace a shell script with all output into a file:

sh -x myscript arg1 arg2 > /var/tmp/tracefile 2>&1