c popen won't catch stderr

c popen stderr
poy picture poy · Aug 1, 2011 · Viewed 18.4k times · Source

I'm trying to use popen() to catch the stderr of a call, but of course it doesn't seem to be doing that. Any ideas?

My code looks more or less like this:

popen("nedit", "r");

But I'm getting all this garbage about non-utf8 on my screen...

Answer

Fred Foo picture Fred Foo · Aug 1, 2011

popen gives you a file handle on a process' stdout, not its stderr. Its first argument is interpreted as a shell command, so you can do redirections in it:

FILE *p = popen("prog 2>&1", "r");

or, if you don't want the stdout at all,

FILE *p = popen("prog 2>&1 >/dev/null", "r");

(Any other file besides /dev/null is acceptable as well.)

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