dup3.c raw

   1  #define _GNU_SOURCE
   2  #include <unistd.h>
   3  #include <errno.h>
   4  #include <fcntl.h>
   5  #include "syscall.h"
   6  
   7  int __dup3(int old, int new, int flags)
   8  {
   9  	int r;
  10  #ifdef SYS_dup2
  11  	if (old==new) return __syscall_ret(-EINVAL);
  12  	if (flags & O_CLOEXEC) {
  13  		while ((r=__syscall(SYS_dup3, old, new, flags))==-EBUSY);
  14  		if (r!=-ENOSYS) return __syscall_ret(r);
  15  	}
  16  	while ((r=__syscall(SYS_dup2, old, new))==-EBUSY);
  17  	if (flags & O_CLOEXEC) __syscall(SYS_fcntl, new, F_SETFD, FD_CLOEXEC);
  18  #else
  19  	while ((r=__syscall(SYS_dup3, old, new, flags))==-EBUSY);
  20  #endif
  21  	return __syscall_ret(r);
  22  }
  23  
  24  weak_alias(__dup3, dup3);
  25