/* rename -- rename a file
  This function is in the public domain. */

/*

@deftypefn Supplemental int rename (const char *@var{old}, const char *@var{new})

Renames a file from @var{old} to @var{new}.  If @var{new} already
exists, it is removed.

@end deftypefn

*/

#include "ansidecl.h"
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <errno.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

int
rename (const char *zfrom, const char *zto)
{
 if (link (zfrom, zto) < 0)
   {
     if (errno != EEXIST)
       return -1;
     if (unlink (zto) < 0
         || link (zfrom, zto) < 0)
       return -1;
   }
 return unlink (zfrom);
}