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

   1
   2 /*
   3  * brkstring.c -- (destructively) split a string into
   4  *             -- an array of substrings
   5  *
   6  * $Id$
   7  *
   8  * This code is Copyright (c) 2002, by the authors of nmh.  See the
   9  * COPYRIGHT file in the root directory of the nmh distribution for
  10  * complete copyright information.
  11  */
  12
  13 #include <h/mh.h>
  14 #include <h/utils.h>
  15
  16 /* allocate this number of pointers at a time */
  17 #define NUMBROKEN 256
  18
  19 static char **broken = NULL;    /* array of substring start addresses */
  20 static int len = 0;             /* current size of "broken"           */
  21
  22 /*
  23  * static prototypes
  24  */
  25 static int brkany (char, char *);
  26
  27
  28 char **
  29 brkstring (char *str, char *brksep, char *brkterm)
  30 {
  31     int i;
  32     char c, *s;
  33
  34     /* allocate initial space for pointers on first call */
  35     if (!broken) {
  36         len = NUMBROKEN;
  37         broken = (char **) mh_xmalloc ((size_t) (len * sizeof(*broken)));
  38     }
  39
  40     /*
  41      * scan string, replacing separators with zeroes
  42      * and enter start addresses in "broken".
  43      */
  44     s = str;
  45
  46     for (i = 0;; i++) {
  47
  48         /* enlarge pointer array, if necessary */
  49         if (i >= len) {
  50             len += NUMBROKEN;
  51             broken = mh_xrealloc (broken, (size_t) (len * sizeof(*broken)));
  52         }
  53
  54         while (brkany (c = *s, brksep))
  55             *s++ = '\0';
  56
  57         /*
  58          * we are either at the end of the string, or the
  59          * terminator found has been found, so finish up.
  60          */
  61         if (!c || brkany (c, brkterm)) {
  62             *s = '\0';
  63             broken[i] = NULL;
  64             return broken;
  65         }
  66
  67         /* set next start addr */
  68         broken[i] = s;
  69
  70         while ((c = *++s) && !brkany (c, brksep) && !brkany (c, brkterm))
  71             ;   /* empty body */
  72     }
  73
  74     return broken;      /* NOT REACHED */
  75 }
  76
  77
  78 /*
  79  * If the character is in the string,
  80  * return 1, else return 0.
  81  */
  82
  83 static int
  84 brkany (char c, char *str)
  85 {
  86     char *s;
  87
  88     if (str) {
  89         for (s = str; *s; s++)
  90             if (c == *s)
  91                 return 1;
  92     }
  93     return 0;
  94 }