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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