Works on one machine, fails on another

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

My program works on this machine:
perl -v "This is perl, version 5.005_03 built for sun4-solaris"

But, not on this machine:
perl -v "This is perl, version 5.003_26"

Here's the portion of code that fails:

50. foreach $key (keys %hash) {
51.    my $tmp = $_;    
52.    my $cmd = "$program $key $matrix ";
53.    $cmd .= "$config_path/CISCO_$tmp.clean " for @{$hash{$key}};
54.    system($cmd) == 0 || die "$cmd failed:$!\n";
55.  }
[download]

Here's what it fails with:

syntax error at ./cflowd-config-gen.pl line 53, near ""$config_path/CI
+SCO_$tmp.clean " for "
syntax error at ./cflowd-config-gen.pl line 53, near "}}"
Execution of ./cflowd-config-gen.pl aborted due to compilation errors.
[download]

I have no idea why this is failing. And, it needs to be run on the machine that it fails on.

Comment on Works on one machine, fails on another Select or Download Code

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(tye)Re: Works on one machine, fails on another by tye (Sage) on Feb 01, 2001 at 23:04 UTC
for wasn't allowed as a statement modifier before 5.005. Check the Changes* files of the source distribution for much more information. Change your "statement for expr" to "for(expr){statement}" to make your code portable to older versions of Perl. - tye (but my friends call me "Tye")	[reply]
Re: Works on one machine, fails on another by runrig (Abbot) on Feb 01, 2001 at 22:57 UTC
system() should return zero (false) on success, so use an 'and', not an 'or' operator. I don't have the precedence of operators memorized, but I'd also change the '\|\|' to 'and' and not '&&'. Update:After checking the precedence, it's not really necessary to use 'and' instead of '&&' here, but to me it makes the intention more clear. Ups! duh. missed the '== 0'. More coffee for me please.	[reply]
Re: Re: Works on one machine, fails on another by arturo (Vicar) on Feb 01, 2001 at 23:02 UTC
ups! Yes, `system` returns 0 on success, so with the explict `system('foo') ==0 \|\| die "bar";` in this situation, that's just what's wanted. If the LHS of the \|\| evaluates as true, Perl won't bother with the RHS. The use of `&&/and` you point to is equivalent to an `if` : If the LHS of an && is true, Perl goes on to evaluate the RHS, but doesn't bother if the LHS is false. So his code is correct on that aspect. I don't know enough Perl history to answer the original question, though =( Just for the record, the 'english' `and` and `or` are 'super-low precedence' versions of `&&` and `\|\|` Philosophy can be made out of anything. Or less -- Jerry A. Fodor	[reply] [d/l] [select]