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The return value is the exit status of the program as returned
by the "wait" call. To get the actual exit value divide by 256.
See also the exec entry elsewhere in this document. This is
*not* what you want to use to capture the output from a command,
for that you should use merely backticks or "qx//", as described
in the section on "`STRING`" in the perlop manpage. Return value
of -1 indicates a failure to start the program (inspect $! for
the reason).