in reply to Re^2: Program unsuspectingly dies with no reason why.
in thread Program unsuspectingly dies with no reason why. -FIXED!

Backticks are for when you want to capture the output of some shell command. In this case, you're redirecting output to a file, so backticks won't do that. Your backticks also don't give you anything in a void context.

That said, putting the same thing in system won't help either. It's the underlying grep that's hanging.

I think that grep needs to get some arguments. You could do this, minimally: 

`grep -v $removeq $sourcefile /dev/null /dev/null > $tempfile`;

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That won't hang, but it also won't work until $removeq and $sourcefile are right. You probably ought to be passing them in initially: 

&clean_the_file( $sourcefile, $removeq );

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I can't tell what $sourcefile should be, though.

Hope this helps.

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Re^4: Program unsuspectingly dies with no reason why.
by misconfiguration (Sexton) on Feb 14, 2008 at 15:20 UTC
    Well so far, even after passing those elements to the subprocess call "&clean_the_file();" I still had no luck. Albeit, I did remember reading about subprocess' being named with funky underscores causing issues with Perl awhile back. This may not be the case, but I removed the name of the sub() function renamed it to cleanthefile();.

    I commented everything out and just printed my variables $sourcefile and $removeq, $sourcefile prints the directory name as expected, BUT - $removeq spits this output out 
    [root@oailxpp02 ccsys]# /root/mkpq -r queue-04
Global symbol "$removeq" requires explicit package name at /root/mkpq 
+line 87.
Execution of /root/mkpq aborted due to compilation errors.

    [download]

    My guess is: the scalar isn't being handled properly, the subprocess can't bring it into it's set of instructions, am I on the right track? Does anyone have any recommendations?
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[d/l]

      The error "Global symbol "$removeq" requires explicit package name" is what you get (under strict) when you try to use a variable named $removeq without declaring it with my. In the code you posted originally, there is a my declaration for $removeq, so I don't know why you'd be getting this error now. I'd need to know what else is changed. Maybe you could post an updated copy of the code you're using.

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[d/l]
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        Updated code
        if ($remove) {
    $remove = lc($remove);
    my %remove_cmd = ( remove => "rmquedev -d $remove -q $remove" );
    print "Are you sure you want to remove print queue \"$remove\" [Y/
+n]?";
    $_ = <>;
    chomp($_);
    $_ = "Y" if ( length($_) == 0 );
    if ( $_ =~ /[Yy]/ ) {

        # Wait for user-input

        system( $remove_cmd {'remove'} );
        print
"Prepairing to remove \"$remove\" from the CC_print.printers file.\n";
        sleep 2;
        my $removeq = $remove;
        &cleanthefile($removeq);
        }
        else {
            die "You chose NOT to remove queue \"$remove\"\n";
        }
    }

        [download]

        Sub-Process 
        sub cleanthefile {
    my $sourcefile = "/u/ccsys/CC_print.printers";
print $removeq;
print "$sourcefile\n";


    # Keep a dedicated backup of CC_print.printers
    if ( -t ne "/root/CC_print.printers.bkp" ) {
        system("touch /root/CC_print.printers.bkp");
        sleep 2;
        system("cp -R $sourcefile /root/CC_print.printer.bkp");
    }
    if ( -t eq "/root/CC_print.printers.bkp" ) {
        system("cp -R $sourcefile /root/CC_print.printer.bkp");

# grab the sourcefile and the string to remove as the first and second
+ arguments
        my ( $sourcefile, $removeq )= @_;
        my $tempfile = "/u/ccsys/CC_print.printers.bkp_mkpq";

        # create a temporary file
        if (-e ne "$tempfile") {
        system("touch /u/ccsys/CC_print.printers.bkp_mkpq");
        }

      # extract lines from $sourcefile which do NOT have the string to
+ remove
      # note that the \' inserts ticks so that strings with spaces can
+ work, too
        if ( -t "$tempfile") {
        #system ("cat $sourcefile \| grep -v $removeq $sourcefile > $t
+empfile");
        #`grep -v $removeq $sourcefile /dev/null /dev/null > $tempfile
+`;
        sleep 1;
        print "Waiting to unlink..\n";

        # delete source file, then rename working file
        unlink($sourcefile);
        rename( $tempfile, $sourcefile );
        system("rm -rf $tempfile");
        }
    }
}

        [download]

        I placed a print statment for $removeq to me it seems as if $removeq is not being passed correctly. I'm rather new to Perl, I wouldn't doubt this is just product of my inexperience with programming in general. No matter how much I read I can't seem to find a solution to this issue!
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[d/l]
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