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From: Behdad E. <bes...@re...> - 2006-08-14 03:59:17
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On Mon, 2006-08-14 at 10:46 +1000, Nicholas Nethercote wrote: > On Sun, 13 Aug 2006, Paul Pluzhnikov wrote: >=20 > > Nigel Horne wrote: > > > >> Since file descriptors are being tracked, it would be useful to warn o= f > >> closing files that aren't open, perhaps --warn-close-fds=3Dyes > > > > You don't need something as advanced as VG for this. > > Simple "strace -etrace=3Dclose ./a.out 2>&1 | grep EBADF" will do. > > > > Note however, that it is somewhat common UNIX practice to > > close FDs that aren't open, and you are likely to encounter > > such code in various libraries (it's often easier to just > > close FD again, rather than keep track of whether it's > > currently open or not). >=20 > Yes, many programs do something not much more sophisticated than this: >=20 > for (i =3D 0; i < BIG_NUMBER; i++) > close(i); >=20 > Nick That's kind of a dumb case of it, still popular. A more sophisticated and common use is to do something like this in daemons: close (0); close (1); close (2); --=20 behdad http://behdad.org/ |