1  /*
       2  
       3  @deftypefn Supplemental char* strdup (const char *@var{s})
       4  
       5  Returns a pointer to a copy of @var{s} in memory obtained from
       6  @code{malloc}, or @code{NULL} if insufficient memory was available.
       7  
       8  @end deftypefn
       9  
      10  */
      11  
      12  #include <ansidecl.h>
      13  #include <stddef.h>
      14  
      15  extern size_t	strlen (const char*);
      16  extern void *malloc (size_t);
      17  extern void *memcpy (void *, const void *, size_t);
      18  
      19  char *
      20  strdup(const char *s)
      21  {
      22    size_t len = strlen (s) + 1;
      23    char *result = (char*) malloc (len);
      24    if (result == (char*) 0)
      25      return (char*) 0;
      26    return (char*) memcpy (result, s, len);
      27  }