summaryrefslogtreecommitdiff
path: root/deps/cares/src/ares_strsplit.c
blob: b57a30f2a99c35a3ff40972f136ba8f50aaac88b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
/* Copyright (C) 2018 by John Schember <john@nachtimwald.com>
 *
 * Permission to use, copy, modify, and distribute this
 * software and its documentation for any purpose and without
 * fee is hereby granted, provided that the above copyright
 * notice appear in all copies and that both that copyright
 * notice and this permission notice appear in supporting
 * documentation, and that the name of M.I.T. not be used in
 * advertising or publicity pertaining to distribution of the
 * software without specific, written prior permission.
 * M.I.T. makes no representations about the suitability of
 * this software for any purpose.  It is provided "as is"
 * without express or implied warranty.
 */

#include "ares_setup.h"
#include "ares_strsplit.h"
#include "ares.h"
#include "ares_private.h"

static int list_contains(char * const *list, size_t num_elem, const char *str, int insensitive)
{
  size_t len;
  size_t i;

  len = strlen(str);
  for (i=0; i<num_elem; i++)
  {
    if (insensitive)
    {
#ifdef WIN32
      if (strnicmp(list[i], str, len) == 0)
#else
      if (strncasecmp(list[i], str, len) == 0)
#endif
        return 1;
    }
    else
    {
      if (strncmp(list[i], str, len) == 0)
        return 1;
    }
  }

  return 0;
}

static int is_delim(char c, const char *delims, size_t num_delims)
{
  size_t i;

  for (i=0; i<num_delims; i++)
  {
    if (c == delims[i])
      return 1;
  }
  return 0;
}


void ares_strsplit_free(char **elms, size_t num_elm)
{
  size_t i;

  if (elms == NULL)
    return;

  for (i=0; i<num_elm; i++)
    ares_free(elms[i]);
  ares_free(elms);
}


char **ares_strsplit(const char *in, const char *delms, int make_set, size_t *num_elm)
{
  char *parsestr;
  char **temp;
  char **out;
  size_t cnt;
  size_t nelms;
  size_t in_len;
  size_t num_delims;
  size_t i;

  if (in == NULL || delms == NULL || num_elm == NULL)
    return NULL;

  *num_elm = 0;

  in_len = strlen(in);
  num_delims = strlen(delms);

  /* Figure out how many elements. */
  nelms = 1;
  for (i=0; i<in_len; i++)
  {
    if (is_delim(in[i], delms, num_delims))
    {
      nelms++;
    }
  }

  /* Copy of input so we can cut it up. */
  parsestr = ares_strdup(in);
  if (parsestr == NULL)
    return NULL;

  /* Temporary array to store locations of start of each element
   * within parsestr. */
  temp = ares_malloc(nelms * sizeof(*temp));
  if (temp == NULL)
  {
    ares_free(parsestr);
    return NULL;
  }
  temp[0] = parsestr;
  cnt = 1;
  for (i=0; i<in_len && cnt<nelms; i++)
  {
    if (!is_delim(parsestr[i], delms, num_delims))
      continue;

    /* Replace sep with NULL. */
    parsestr[i] = '\0';
    /* Add the pointer to the array of elements */
    temp[cnt] = parsestr+i+1;
    cnt++;
  }

  /* Copy each element to our output array. */
  out = ares_malloc(nelms * sizeof(*out));
  if (out == NULL)
  {
    ares_free(parsestr);
    ares_free(temp);
    return NULL;
  }

  nelms = 0;
  for (i=0; i<cnt; i++)
  {
    if (temp[i][0] == '\0')
      continue;

    if (make_set && list_contains(out, nelms, temp[i], 1))
      continue;

    out[nelms] = ares_strdup(temp[i]);
    if (out[nelms] == NULL)
    {
      ares_strsplit_free(out, nelms);
      ares_free(parsestr);
      ares_free(temp);
      return NULL;
    }
    nelms++;
  }


  /* If there are no elements don't return an empty allocated
   * array. */
  if (nelms == 0)
  {
    ares_strsplit_free(out, nelms);
    out = NULL;
  }

  /* Get the true number of elements (recalculated because of make_set) */
  *num_elm = nelms;

  ares_free(parsestr);
  ares_free(temp);
  return out;
}