w3ntp has asked for the wisdom of the Perl Monks concerning the following question:

This is a clarification of my prior question: 
#!/usr/local/bin/perl
chomp($_=$ARGV[0]);
system `echo   $_  > /tmp/gerbil.txt`;
exit;

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If I run the script this is what I get 
/try.pl a|b|c|d
bash: b: command not found
bash: c: command not found
bash: d: command not found

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The program above is passed live data one line at a time. It does not contain any # charters. Any thoughtt? thanks

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Re: How to read in pipe characters
by Anonymous Monk on Oct 07, 2010 at 12:17 UTC
    The pipe character means something special to your shell: for most, it means to pipe the output of one command to the input of the next. Quote your argument string, eg "a|b". See your shell's documentation for quoting rules and special characters.
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Re: How to read in data with pipe characters
by ww (Archbishop) on Oct 07, 2010 at 12:22 UTC
    Don't "clarify" by starting a new thread. Edit, <strike>ing as necessary (but leave an audit trail of your original post, so as to keep any replies in context.

    Reaped: How to read in data with pipe chars has been considered for reaping.

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Re: How to read in data with pipe characters
by cdarke (Prior) on Oct 07, 2010 at 12:31 UTC
    /try.pl a|b|c|d

    It is unusual to run a script from the root directory, you probably mean:
    ./try.pl 'a|b|c|d'

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    but that is a shell question, it has nothing to do with Perl.
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Re: How to read in data with pipe characters
by JavaFan (Canon) on Oct 07, 2010 at 13:34 UTC 
    /try.pl a|b|c|d
bash: b: command not found
bash: c: command not found
bash: d: command not found

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    That's an error you're getting due to bash, not Perl. You tell bash to call "/try.pl" with the argument 'a', and pipe the result into b, its result into c, and that result into d.

    You probably want /try.pl 'a|b|c|d'. But, we aren't done. Once you have 'a|b|c|d', you feed it back into a shell. So, again, you need to escape it, but putting quotes around $_.

    But why are you writing a Perl program which all it does it take input, and feed the input back to another shell? Why not just: 

    #!/usr/bin/sh
echo $1 > /tmp/gerbil.txt

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    However, if you do write it in Perl, why both the backticks, and system? Do you even know what the backticks do? Now you are saying: "Perl, please start a shell, and execute the command I'm giving you. Gather the output, and starts a second shell, executing whatever was written to STDOUT by the first shell." Is that really your intention?
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Re: How to read in data with pipe characters
by Anonymous Monk on Oct 07, 2010 at 12:27 UTC
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