I think you were on to something the first time. -t will check if the filehandle is hooked up to a tty, which is the case if you run it from the command line, without a pipe. So you can check with -t and check the arguments, and give an appropriate error message.

Now, if the program is run through a fork/exec, or another non-interactive facility, you can't really know until the parent process closes its stdout. The parent might wait for 5 years before it decides to print something out, so any check based on testing for actual input would be wrong.

Goldclaw

In reply to Re: Re: Test for standard input by goldclaw
in thread Test for standard input by Anonymous Monk

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