Changing tty's in perl

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

I have an application that i'm executing with in perl with the system("cmd &") call. For some reason it is requiring it have STDIN. I have closed all STDIN, STDOUT STDERR fd's and tried the POSIX setsid(). All with no luck. Is there anyway in perl I can switch the tty with posix functions and (or) fool the application into a another non-used tty?

Originally posted as a Categorized Question.

Comment on Changing tty's in perl

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Re: Changing tty's in perl by kjherron (Pilgrim) on Aug 11, 2001 at 23:55 UTC
The posix way to obtain a new controlling tty is to first get rid of the old one, as you've outlined, and then open a new one; the first one opened becomes the new controlling tty. You can't use "/dev/tty" for this purpose of course, you'd have to open a real tty device. These are /dev/pty*, /dev/console, and devices corresponding to actual serial ports. Is the program insisting on a tty, or just a valid stdin? Instead of just closing stdin/stdout/stderr you can try opening them to /dev/null, and see if that is sufficient. If it needs a tty, one can often use /dev/console.	[reply]

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Re: Changing tty's in perl
by kjherron (Pilgrim) on Aug 11, 2001 at 23:55 UTC

Is the program insisting on a tty, or just a valid stdin? Instead of just closing stdin/stdout/stderr you can try opening them to /dev/null, and see if that is sufficient. If it needs a tty, one can often use /dev/console.

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