problem starting perl script from cron environment - ps: don't knowwhich terminal to select

[Micha]

I have perl program which works just fine on the console, but started
in cron environment it prints "ps: don't know which terminal to
select" to stderr - btw I don't call ps explicitly at any point in my
scripts.

Now lets have a look at the details :

My script is written in perl, inside that script there is a call in
backquotes to an other perl script which starts too.
By printf-debugging I could find out that the "ps: don't know which
terminal to select" output occurs both in the parent and child script
before by first line of code. Does perl call ps before starting?? why
does it need a terminal? my script do not process stdin and stdout +
stderr are redirected into files. And for some reason this problem
occurs only when calling a perl script from an other perl script.

In interactive mode the script works just fine - I ran it from a ksh.
To execute it via cron I write a small ksh script, which reads the
environment from the .kshrc an the executes the per script sending
stdout and stderr to log-files.

Let me try to deconfuse it

Cron -> ksh-Script -> perlA -> perlB -> perlC

-when calling perlA from ksh - ok, no message
- when calling perlB from perlA or perlC from perlB - there
is a stderr message "ps: don't know which terminal to select"
which must be caused before my first line of code in the child
script

Thanks in advance, Micha

 

[Micha]

Cron doesn't.
perl doesn't.
Perhaps your ksh startup file calls it.....

no it doesn't - still wondering why, currently I'm using a
workaround without cron. But somehow that problem still bothers me.

 

[Henry Law]

no it doesn't - still wondering why, currently I'm using a

You say that, and indeed you may be right, but I'd encourage you to look
at it again, since it seems to be the most likely cause of a call to a
system utility which you've not coded. Remember that cron runs in quite
a different environment to that in your terminal: it has its own set of
environment variables, for example, and (I presume) could also have its
own shell startup script.

BTW unless it turns back into a Perl error pretty soon we should stop
discussing in comp.lang.perl.misc! Set followups if appropriate.