43634df2d6a0a7ef4a8d586b6ea97f6522fb0205
1 /**
2 * collectd - src/utils_subst.c
3 * Copyright (C) 2008 Sebastian Harl
4 *
5 * Permission is hereby granted, free of charge, to any person obtaining a
6 * copy of this software and associated documentation files (the "Software"),
7 * to deal in the Software without restriction, including without limitation
8 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
9 * and/or sell copies of the Software, and to permit persons to whom the
10 * Software is furnished to do so, subject to the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be included in
13 * all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
21 * DEALINGS IN THE SOFTWARE.
22 *
23 * Authors:
24 * Sebastian "tokkee" Harl <sh at tokkee.org>
25 **/
27 /*
28 * This module provides functions for string substitution.
29 */
31 #include "collectd.h"
32 #include "common.h"
34 char *subst (char *buf, size_t buflen, const char *string, size_t off1, size_t off2,
35 const char *replacement)
36 {
37 char *out = buf;
39 char const *front;
40 char const *back;
41 size_t front_len;
42 size_t replacement_len;
43 size_t back_len;
45 if ((NULL == buf) || (0 == buflen) || (NULL == string) || (NULL == replacement))
46 return NULL;
48 size_t string_len = strlen (string);
49 if ((off1 > string_len) || (off2 > string_len) || (off1 > off2))
50 return NULL;
52 front = string;
53 back = string + off2;
54 front_len = off1;
55 replacement_len = strlen (replacement);
56 back_len = strlen (back);
58 if (front_len >= buflen) {
59 front_len = buflen - 1;
60 replacement_len = 0;
61 back_len = 0;
62 } else if ((front_len + replacement_len) >= buflen) {
63 replacement_len = buflen - (front_len + 1);
64 back_len = 0;
65 } else if ((front_len + replacement_len + back_len) >= buflen) {
66 back_len = buflen - (front_len + replacement_len + 1);
67 } else {
68 buflen = front_len + replacement_len + back_len + 1;
69 }
70 assert ((front_len + replacement_len + back_len) == (buflen - 1));
72 if (front_len != 0) {
73 sstrncpy (out, front, front_len + 1);
74 out += front_len;
75 }
77 if (replacement_len != 0) {
78 sstrncpy (out, replacement, replacement_len + 1);
79 out += replacement_len;
80 }
82 if (back_len != 0) {
83 sstrncpy (out, back, back_len + 1);
84 out += back_len;
85 }
87 out[0] = 0;
88 return buf;
89 } /* subst */
91 char *asubst (const char *string, int off1, int off2, const char *replacement)
92 {
93 char *buf;
94 int len;
96 char *ret;
98 if ((NULL == string) || (0 > off1) || (0 > off2) || (off1 > off2)
99 || (NULL ==replacement))
100 return NULL;
102 len = off1 + strlen (replacement) + strlen (string) - off2 + 1;
104 buf = (char *)malloc (len);
105 if (NULL == buf)
106 return NULL;
108 ret = subst (buf, len, string, off1, off2, replacement);
109 if (NULL == ret)
110 free (buf);
111 return ret;
112 } /* asubst */
114 char *subst_string (char *buf, size_t buflen, const char *string,
115 const char *needle, const char *replacement)
116 {
117 size_t needle_len;
118 size_t i;
120 if ((buf == NULL) || (string == NULL)
121 || (needle == NULL) || (replacement == NULL))
122 return (NULL);
124 needle_len = strlen (needle);
125 sstrncpy (buf, string, buflen);
127 /* Limit the loop to prevent endless loops. */
128 for (i = 0; i < buflen; i++)
129 {
130 char temp[buflen];
131 char *begin_ptr;
132 size_t begin;
134 /* Find `needle' in `buf'. */
135 begin_ptr = strstr (buf, needle);
136 if (begin_ptr == NULL)
137 break;
139 /* Calculate the start offset. */
140 begin = begin_ptr - buf;
142 /* Substitute the region using `subst'. The result is stored in
143 * `temp'. */
144 begin_ptr = subst (temp, buflen, buf,
145 begin, begin + needle_len,
146 replacement);
147 if (begin_ptr == NULL)
148 {
149 WARNING ("subst_string: subst failed.");
150 break;
151 }
153 /* Copy the new string in `temp' to `buf' for the next round. */
154 strncpy (buf, temp, buflen);
155 }
157 if (i >= buflen)
158 {
159 WARNING ("subst_string: Loop exited after %zu iterations: "
160 "string = %s; needle = %s; replacement = %s;",
161 i, string, needle, replacement);
162 }
164 return (buf);
165 } /* char *subst_string */
167 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */