dup2

[Jean-Pierre Radley]

In article <27B1CA1C.22559 at ics.uci.edu> schmidt at ics.uci.edu (Doug Schmidt) writes:
>	I'm curious, is it possible to implement the dup2() system
>call using only routines available in the standard C library and other
>existing system calls?

>From the xcmalt sources:

#if !DUP2		/* For those that do not have dup2() */
#include <fcntl.h>
dup2(oldfd, newfd)
int oldfd, newfd;
{
   if (fcntl(oldfd, F_GETFL, 0) == -1)      /* Valid file descriptor? */
       return (-1);                         /* No, return an error */
   close(newfd);                            /* Ensure newfd is closed */
   return (fcntl(oldfd, F_DUPFD, newfd));   /* Dup oldfd into newfd */
}
#endif /* !DUP2Thanks to Bill Allie CIS: 76703,2061 */

 Jean-Pierre Radley   NYC Public Unix   jpr at jpradley.jpr.com   CIS: 72160,1341