skalibs

Mirror/fork of https://skarnet.org/software/skalibs/
git clone https://ccx.te2000.cz/git/skalibs
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fd_ensure_open.c (439B)

      1 /* ISC license. */
      2 
      3 #include <errno.h>
      4 
      5 #include <skalibs/fcntl.h>
      6 #include <skalibs/djbunix.h>
      7 
      8 int fd_ensure_open (int fd, int w)
      9 {
     10   int dummy ;
     11   if (fcntl(fd, F_GETFD, &dummy) == -1)
     12   {
     13     int newfd ;
     14     if (errno != EBADF) return 0 ;
     15     newfd = open2("/dev/null", w ? O_WRONLY : O_RDONLY) ;
     16     if (newfd == -1) return 0 ;
     17     if (fd_move(fd, newfd) == -1)
     18     {
     19       fd_close(newfd) ;
     20       return 0 ;
     21     }
     22   }
     23   return 1 ;
     24 }