Problems with sending value to system command

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

Hi Monks, I have problems with sending values. IE.

         my $returnvalue = "$pin=" . &TransformBooleanEquation($functi
+on) if (length($function) > 0);
   
         print "[RETURN] $returnvalue\n";
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what i see at the output is : RETURN S=(((\!CS)&(A^B^\!CI0N))|(CS&(A^B^\!CI1N))).

         my $outputValueFromFindArcsScript = system("/proj/dance.pl '$
+returnvalue'") if (length($function) > 0);
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now when i do this, it fails. If i wanted to do this manually in the terminal window, I execute the code below and it works.

/proj/dance.pl 'S=(((\!CS)&(A^B^\!CI0N))|(CS&(A^B^\!CI1N)))'
[download]

why won't my perl code execute this?

Comment on Problems with sending value to system command Select or Download Code

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Re: Problems with sending value to system command by Errto (Vicar) on Dec 04, 2004 at 01:42 UTC
The builtin `system` does not return the text that the called program writes to standard output. For that you should use the backtick operator (``). But I have a question for you. Why call one Perl program from another as a separate process? Why not just modify the called program to have a subroutine return a value instead of printing it out and then make it a module?	[reply] [d/l]
Re^2: Problems with sending value to system command by EchoAngel (Pilgrim) on Dec 04, 2004 at 03:02 UTC
i tried using the backtick operator. the problem is that when the system command is called, the script doesn't operator and dies	[reply]
Re^3: Problems with sending value to system command by jdalbec (Deacon) on Dec 04, 2004 at 04:18 UTC
You can't combine system() and the backtick operator. Try my $outputValueFromFindArcsScript = `/proj/dance.pl '$returnvalue'` if + (length($function) > 0); [download]	[reply] [d/l]
Re: Problems with sending value to system command by dave_the_m (Monsignor) on Dec 04, 2004 at 12:52 UTC
Never have an `if` statement modifier on the end of a statement containg a `my` declaration. It will do Strange Things related to old values hanging aroung from previous calls to the enclosing block. ie replace `my $x = .... if $y;` [download] with `my $x; $x = .... if $y;` [download] Dave.	[reply] [d/l] [select]
Re^2: Problems with sending value to system command by EchoAngel (Pilgrim) on Dec 06, 2004 at 22:02 UTC
I found out that the reason it doesn't work is that I must not include the \! within the value when sending through Perl. However, on the command line, the \! must be included.	[reply]