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

   1
   2 /*
   3  * utils.c -- various utility routines
   4  *
   5  * $Id$
   6  *
   7  * This code is Copyright (c) 2006, by the authors of nmh.  See the
   8  * COPYRIGHT file in the root directory of the nmh distribution for
   9  * complete copyright information.
  10  */
  11
  12 #include <h/mh.h>
  13 #include <h/utils.h>
  14 #include <stdlib.h>
  15
  16 /*
  17  * Safely call malloc
  18  */
  19 void *
  20 mh_xmalloc(size_t size)
  21 {
  22     void *memory;
  23
  24     if (size == 0)
  25         adios(NULL, "Tried to malloc 0 bytes");
  26
  27     memory = malloc(size);
  28     if (!memory)
  29         adios(NULL, "Malloc failed");
  30
  31     return memory;
  32 }
  33
  34 /*
  35  * Safely call realloc
  36  */
  37 void *
  38 mh_xrealloc(void *ptr, size_t size)
  39 {
  40     void *memory;
  41
  42     if (size == 0)
  43         adios(NULL, "Tried to realloc 0bytes");
  44
  45     memory = realloc(ptr, size);
  46     if (!memory)
  47         adios(NULL, "Realloc failed");
  48
  49     return memory;
  50 }
  51
  52 /*
  53  * Return the present working directory, if the current directory does not
  54  * exist, or is too long, make / the pwd.
  55  */
  56 char *
  57 pwd(void)
  58 {
  59     register char *cp;
  60     static char curwd[PATH_MAX];
  61
  62     if (!getcwd (curwd, PATH_MAX)) {
  63         admonish (NULL, "unable to determine working directory");
  64         if (!mypath || !*mypath
  65                 || (strcpy (curwd, mypath), chdir (curwd)) == -1) {
  66             strcpy (curwd, "/");
  67             chdir (curwd);
  68         }
  69         return curwd;
  70     }
  71
  72     if ((cp = curwd + strlen (curwd) - 1) > curwd && *cp == '/')
  73         *cp = '\0';
  74
  75     return curwd;
  76 }
  77
  78 /*
  79  * add   -- If "s1" is NULL, this routine just creates a
  80  *       -- copy of "s2" into newly malloc'ed memory.
  81  *       --
  82  *       -- If "s1" is not NULL, then copy the concatenation
  83  *       -- of "s1" and "s2" (note the order) into newly
  84  *       -- malloc'ed memory.  Then free "s1".
  85  */
  86 char *
  87 add (char *s2, char *s1)
  88 {
  89     char *cp;
  90     size_t len1 = 0, len2 = 0;
  91
  92     if (s1)
  93         len1 = strlen (s1);
  94     if (s2)
  95         len2 = strlen (s2);
  96
  97     cp = mh_xmalloc (len1 + len2 + 1);
  98
  99     /* Copy s1 and free it */
 100     if (s1) {
 101         memcpy (cp, s1, len1);
 102         free (s1);
 103     }
 104
 105     /* Copy s2 */
 106     if (s2)
 107         memcpy (cp + len1, s2, len2);
 108
 109     /* Now NULL terminate the string */
 110     cp[len1 + len2] = '\0';
 111
 112     return cp;
 113 }