diplodocus.org Git - nmh/blob - sbr/add.c

   1
   2 /*
   3  * add.c -- If "s1" is NULL, this routine just creates a
   4  *       -- copy of "s2" into newly malloc'ed memory.
   5  *       --
   6  *       -- If "s1" is not NULL, then copy the concatenation
   7  *       -- of "s1" and "s2" (note the order) into newly
   8  *       -- malloc'ed memory.  Then free "s1".
   9  *
  10  * $Id$
  11  *
  12  * This code is Copyright (c) 2002, by the authors of nmh.  See the
  13  * COPYRIGHT file in the root directory of the nmh distribution for
  14  * complete copyright information.
  15  */
  16
  17 #include <h/mh.h>
  18
  19 char *
  20 add (char *s2, char *s1)
  21 {
  22     char *cp;
  23     size_t len1 = 0, len2 = 0;
  24
  25     if (s1)
  26         len1 = strlen (s1);
  27     if (s2)
  28         len2 = strlen (s2);
  29
  30
  31     if (!(cp = malloc (len1 + len2 + 1)))
  32         adios (NULL, "unable to allocate string storage");
  33
  34     /* Copy s1 and free it */
  35     if (s1) {
  36         memcpy (cp, s1, len1);
  37         free (s1);
  38     }
  39
  40     /* Copy s2 */
  41     if (s2)
  42         memcpy (cp + len1, s2, len2);
  43
  44     /* Now NULL terminate the string */
  45     cp[len1 + len2] = '\0';
  46
  47     return cp;
  48 }