src/unistd/dup2.c

   1 #include <unistd.h>
   2 #include <errno.h>
   3 #include <fcntl.h>
   4 #include "syscall.h"
   5
   6 int dup2(int old, int new)
   7 {
   8         int r;
   9 #ifdef SYS_dup2
  10         while ((r=__syscall(SYS_dup2, old, new))==-EBUSY);
  11 #else
  12         if (old==new) {
  13                 r = __syscall(SYS_fcntl, old, F_GETFD);
  14                 if (r >= 0) return old;
  15         } else {
  16                 while ((r=__syscall(SYS_dup3, old, new, 0))==-EBUSY);
  17         }
  18 #endif
  19         return __syscall_ret(r);
  20 }