Re: Test whether STDOUT is connected to a file

Why not simply pass the filename of the file-to-be-written to the program, and let it do the file writing in any case?

On Linux, the -p file test can tell you if STDOUT is connected to a pipe, no idea if that works on windows too (Update: -t is probably more informative than -p).

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Comment on Re: Test whether STDOUT is connected to a file

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Re^2: Test whether STDOUT is connected to a file by rovf (Priest) on Aug 18, 2010 at 13:29 UTC
Why not simply pass the filename of the file-to-be-written to the program, and let it do the file writing in any case? Because if I do this, I don't get any diagnostics about the error case. Note that I still guess what's going on, so for example the information "STDOUT in the error case is still connected to the same stream as in the parent" would be helpful. On Linux, the -p file test can tell you if STDOUT is connected to a pipe, no idea if that works on windows too (Update: -t is probably more informative than -p). There is an entry in perlfaq8 about this, which is not very encouraging: How do I find out if I'm running interactively or not? Good question. Sometimes "-t STDIN" and "-t STDOUT" can give clues, sometimes not. if (-t STDIN && -t STDOUT) { print "Now what? "; } -- Ronald Fischer <ynnor@mm.st>	[reply] [d/l]
Re^3: Test whether STDOUT is connected to a file by wazoox (Prior) on Aug 19, 2010 at 10:46 UTC
Because if I do this, I don't get any diagnostics about the error case. You could redirect the STDERR to STDOUT in the called perl program, then you wouldn't need to rely upon a broken bourne-shell emulation under windows.	[reply]