Re: [PATCH] Clean up file descriptors when calling hooks.

linux@horizon.com writes:

E.g. imagine if I ran gcc -c file.c, and it assigned file.c to fd 0,
file.h to fd1, and file.o to fd 2.   Then wants to print a warning
message... right into the middle of the binary.  (Oversimplified
example, because gcc is actually several separate programs, but
hopefully you get the idea.)

It's just safer to leave those fds open to a null device.

Overdangerous example.  Do people realize hooks run without any
locking?