Re: Leaking a file descriptor into a child to use with /proc/self/fd/3

Might also want to look at $^F (see perlvar) and/or explicitly clearing CLOEXEC on the descriptor with fcntl.

The cake is a lie.
The cake is a lie.
The cake is a lie.

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Re^2: Leaking a file descriptor into a child to use with /proc/self/fd/3 by ewheeler (Novice) on Feb 26, 2020 at 23:46 UTC
Perfect, that fixed the problem. I did not realize Perl closed FDs on exec (or maybe that is an OS thing).	[reply]
Re^3: Leaking a file descriptor into a child to use with /proc/self/fd/3 by Your Mother (Archbishop) on Feb 26, 2020 at 23:55 UTC
The Perl process essentially goes away by replacing itself when you `exec`. So, it might feel surprising but it seems sensible/intuitive that any FDs opened in Perl would close.	[reply] [d/l]
Re^3: Leaking a file descriptor into a child to use with /proc/self/fd/3 by ewheeler (Novice) on Feb 26, 2020 at 23:59 UTC
This worked: `open(my $in, '/etc/passwd'); my $flags = fcntl($in, F_GETFD, 0); fcntl($in, F_SETFD, $flags & (~FD_CLOEXEC)) or die "Can't set flags: $ +!\n"; if (!fork()) { exec("grep", "root", "/proc/self/fd/" . fileno($in)); } close($in);` [download]	[reply] [d/l]