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