Re: bash: Correct usage of F_SETFD

[Chet Ramey]

> include/filecntl.h in bash-4.1 has following:
> 
> #define SET_CLOSE_ON_EXEC(fd)  (fcntl ((fd), F_SETFD, FD_CLOEXEC))
> 
> Is that really the correct/intended usage of F_SETFD ?

     F_SETFD            Set the close-on-exec flag associated with fildes to
                        the low order bit of arg (0 or 1 as above).

> If kernel ever adds a new flag to the fd, this would end up clearing the
> other new flag right ?
> 
> Shouldn't bash use F_GETFD to get the current flags and set/clear just
> the FD_CLOEXEC bit ?

I suppose it would matter if there are systems that have more than one
flag value.

Chet

-- 
``The lyf so short, the craft so long to lerne.'' - Chaucer
                 ``Ars longa, vita brevis'' - Hippocrates
Chet Ramey, ITS, CWRU    chet@case.edu    http://cnswww.cns.cwru.edu/~chet/