$? funkyness

mutated has asked for the wisdom of the Perl Monks concerning the following question:

Hi Monks, I have a process that normaly gets started in the background ala redhat service.If I run it in the forground

my $foo = `true`;
my $err = $? >> 8;
system("echo Error code is $err >> /tmp/foo");
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$err is 0 but if I run the same code detached from the tty and running in the background $err is 16777215 ..I've tried other proccess calling:

#!/usr/bin/perl
exit 0;
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returns the same result...am I on crack?

Edited by BazB: added code tags

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Re: $? funkyness by Old_Gray_Bear (Bishop) on Feb 11, 2004 at 21:45 UTC
16777215 looks remarkably like '-1' shifted right eight bits. (In two's complement notation (I think that the term I want).) What we have is "shift the argument to the right and fill in the vacated bits with the sign bit". A physical shift rather than a logical shift, at the hardware level. Someone is trying to tell you that something in your backgrounding of the process is going awry. Perhaps a difference in ENV variables between fore- and back-ground. (At a guess.) ---- I Go Back to Sleep, Now. OGB	[reply]
Re: $? funkyness by bluto (Curate) on Feb 12, 2004 at 00:46 UTC
Check your PATH environment variable or use full paths to executables (i.e. 'true' should be '/bin/true' or '/usr/bin/true' depending on your machine). I get the same error (16777215) if I replace 'true' with 'bogus'). bluto	[reply]