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"
33 #include "utils_subst.h"
35 char *subst (char *buf, size_t buflen, const char *string, int off1, int off2,
36 const char *replacement)
37 {
38 char *buf_ptr = buf;
39 size_t len = buflen;
41 if ((NULL == buf) || (0 >= buflen) || (NULL == string)
42 || (0 > off1) || (0 > off2) || (off1 > off2)
43 || (NULL == replacement))
44 return NULL;
46 sstrncpy (buf_ptr, string,
47 ((size_t)off1 + 1 > buflen) ? buflen : (size_t)off1 + 1);
48 buf_ptr += off1;
49 len -= off1;
51 if (0 >= len)
52 return buf;
54 sstrncpy (buf_ptr, replacement, len);
55 buf_ptr += strlen (replacement);
56 len -= strlen (replacement);
58 if (0 >= len)
59 return buf;
61 sstrncpy (buf_ptr, string + off2, len);
62 return buf;
63 } /* subst */
65 char *asubst (const char *string, int off1, int off2, const char *replacement)
66 {
67 char *buf;
68 int len;
70 char *ret;
72 if ((NULL == string) || (0 > off1) || (0 > off2) || (off1 > off2)
73 || (NULL ==replacement))
74 return NULL;
76 len = off1 + strlen (replacement) + strlen (string) - off2 + 1;
78 buf = (char *)malloc (len);
79 if (NULL == buf)
80 return NULL;
82 ret = subst (buf, len, string, off1, off2, replacement);
83 if (NULL == ret)
84 free (buf);
85 return ret;
86 } /* asubst */
88 char *subst_string (char *buf, size_t buflen, const char *string,
89 const char *needle, const char *replacement)
90 {
91 char *temp;
92 size_t needle_len;
93 size_t i;
95 if ((buf == NULL) || (string == NULL)
96 || (needle == NULL) || (replacement == NULL))
97 return (NULL);
99 temp = (char *) malloc (buflen);
100 if (temp == NULL)
101 {
102 ERROR ("subst_string: malloc failed.");
103 return (NULL);
104 }
106 needle_len = strlen (needle);
107 strncpy (buf, string, buflen);
109 /* Limit the loop to prevent endless loops. */
110 for (i = 0; i < buflen; i++)
111 {
112 char *begin_ptr;
113 size_t begin;
115 /* Find `needle' in `buf'. */
116 begin_ptr = strstr (buf, needle);
117 if (begin_ptr == NULL)
118 break;
120 /* Calculate the start offset. */
121 begin = begin_ptr - buf;
123 /* Substitute the region using `subst'. The result is stored in
124 * `temp'. */
125 begin_ptr = subst (temp, buflen, buf,
126 begin, begin + needle_len,
127 replacement);
128 if (begin_ptr == NULL)
129 {
130 WARNING ("subst_string: subst failed.");
131 break;
132 }
134 /* Copy the new string in `temp' to `buf' for the next round. */
135 strncpy (buf, temp, buflen);
136 }
138 if (i >= buflen)
139 {
140 WARNING ("subst_string: Loop exited after %zu iterations: "
141 "string = %s; needle = %s; replacement = %s;",
142 i, string, needle, replacement);
143 }
145 sfree (temp);
146 return (buf);
147 } /* char *subst_string */
149 /* vim: set sw=4 ts=4 tw=78 noexpandtab : */