src/lib/smartlist_core/smartlist_split.c

   1 /* Copyright (c) 2003-2004, Roger Dingledine
   2  * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson.
   3  * Copyright (c) 2007-2021, The Tor Project, Inc. */
   4 /* See LICENSE for licensing information */
   5
   6 /**
   7  * \file smartlist_split.c
   8  * \brief Split a string into a smartlist_t of substrings.
   9  **/
  10
  11 #include "lib/smartlist_core/smartlist_core.h"
  12 #include "lib/smartlist_core/smartlist_split.h"
  13
  14 #include "lib/err/torerr.h"
  15 #include "lib/string/util_string.h"
  16 #include "lib/string/compat_ctype.h"
  17 #include "lib/malloc/malloc.h"
  18
  19 #include <string.h>
  20
  21 /**
  22  * Split a string <b>str</b> along all occurrences of <b>sep</b>,
  23  * appending the (newly allocated) split strings, in order, to
  24  * <b>sl</b>.  Return the number of strings added to <b>sl</b>.
  25  *
  26  * If <b>flags</b>&amp;SPLIT_SKIP_SPACE is true, remove initial and
  27  * trailing space from each entry.
  28  * If <b>flags</b>&amp;SPLIT_IGNORE_BLANK is true, remove any entries
  29  * of length 0.
  30  * If <b>flags</b>&amp;SPLIT_STRIP_SPACE is true, strip spaces from each
  31  * split string.
  32  *
  33  * If <b>max</b>\>0, divide the string into no more than <b>max</b> pieces. If
  34  * <b>sep</b> is NULL, split on any sequence of horizontal space.
  35  */
  36 int
  37 smartlist_split_string(smartlist_t *sl, const char *str, const char *sep,
  38                        int flags, int max)
  39 {
  40   const char *cp, *end, *next;
  41   int n = 0;
  42
  43   raw_assert(sl);
  44   raw_assert(str);
  45
  46   cp = str;
  47   while (1) {
  48     if (flags&SPLIT_SKIP_SPACE) {
  49       while (TOR_ISSPACE(*cp)) ++cp;
  50     }
  51
  52     if (max>0 && n == max-1) {
  53       end = strchr(cp,'\0');
  54     } else if (sep) {
  55       end = strstr(cp,sep);
  56       if (!end)
  57         end = strchr(cp,'\0');
  58     } else {
  59       for (end = cp; *end && *end != '\t' && *end != ' '; ++end)
  60         ;
  61     }
  62
  63     raw_assert(end);
  64
  65     if (!*end) {
  66       next = NULL;
  67     } else if (sep) {
  68       next = end+strlen(sep);
  69     } else {
  70       next = end+1;
  71       while (*next == '\t' || *next == ' ')
  72         ++next;
  73     }
  74
  75     if (flags&SPLIT_SKIP_SPACE) {
  76       while (end > cp && TOR_ISSPACE(*(end-1)))
  77         --end;
  78     }
  79     if (end != cp || !(flags&SPLIT_IGNORE_BLANK)) {
  80       char *string = tor_strndup(cp, end-cp);
  81       if (flags&SPLIT_STRIP_SPACE)
  82         tor_strstrip(string, " ");
  83       smartlist_add(sl, string);
  84       ++n;
  85     }
  86     if (!next)
  87       break;
  88     cp = next;
  89   }
  90
  91   return n;
  92 }