FAQ 8.26 Why doesn't open() return an error when a pipe open fails?

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8.26: Why doesn't open() return an error when a pipe open fails?

    If the second argument to a piped open() contains shell metacharacters,
    perl fork()s, then exec()s a shell to decode the metacharacters and
    eventually run the desired program. If the program couldn't be run, it's
    the shell that gets the message, not Perl. All your Perl program can
    find out is whether the shell itself could be successfully started. You
    can still capture the shell's STDERR and check it for error messages.
    See "How can I capture STDERR from an external command?" elsewhere in
    this document, or use the IPC::Open3 module.

    If there are no shell metacharacters in the argument of open(), Perl
    runs the command directly, without using the shell, and can correctly
    report whether the command started.


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