1 | /* $OpenBSD$ */ |
2 | |
3 | /* |
4 | * Copyright (c) 2019 Nicholas Marriott <[email protected]> |
5 | * |
6 | * Permission to use, copy, modify, and distribute this software for any |
7 | * purpose with or without fee is hereby granted, provided that the above |
8 | * copyright notice and this permission notice appear in all copies. |
9 | * |
10 | * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES |
11 | * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF |
12 | * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR |
13 | * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES |
14 | * WHATSOEVER RESULTING FROM LOSS OF MIND, USE, DATA OR PROFITS, WHETHER |
15 | * IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING |
16 | * OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. |
17 | */ |
18 | |
19 | #include <sys/types.h> |
20 | |
21 | #include <regex.h> |
22 | #include <string.h> |
23 | |
24 | #include "tmux.h" |
25 | |
26 | static void |
27 | regsub_copy(char **buf, size_t *len, const char *text, size_t start, |
28 | size_t end) |
29 | { |
30 | size_t add = end - start; |
31 | |
32 | *buf = xrealloc(*buf, (*len) + add + 1); |
33 | memcpy((*buf) + *len, text + start, add); |
34 | (*len) += add; |
35 | } |
36 | |
37 | static void |
38 | regsub_expand(char **buf, size_t *len, const char *with, const char *text, |
39 | regmatch_t *m, u_int n) |
40 | { |
41 | const char *cp; |
42 | u_int i; |
43 | |
44 | for (cp = with; *cp != '\0'; cp++) { |
45 | if (*cp == '\\') { |
46 | cp++; |
47 | if (*cp >= '0' && *cp <= '9') { |
48 | i = *cp - '0'; |
49 | if (i < n && m[i].rm_so != m[i].rm_eo) { |
50 | regsub_copy(buf, len, text, m[i].rm_so, |
51 | m[i].rm_eo); |
52 | continue; |
53 | } |
54 | } |
55 | } |
56 | *buf = xrealloc(*buf, (*len) + 2); |
57 | (*buf)[(*len)++] = *cp; |
58 | } |
59 | } |
60 | |
61 | char * |
62 | regsub(const char *pattern, const char *with, const char *text, int flags) |
63 | { |
64 | regex_t r; |
65 | regmatch_t m[10]; |
66 | ssize_t start, end, last, len = 0; |
67 | int empty = 0; |
68 | char *buf = NULL; |
69 | |
70 | if (*text == '\0') |
71 | return (xstrdup("" )); |
72 | if (regcomp(&r, pattern, flags) != 0) |
73 | return (NULL); |
74 | |
75 | start = 0; |
76 | last = 0; |
77 | end = strlen(text); |
78 | |
79 | while (start <= end) { |
80 | if (regexec(&r, text + start, nitems(m), m, 0) != 0) { |
81 | regsub_copy(&buf, &len, text, start, end); |
82 | break; |
83 | } |
84 | |
85 | /* |
86 | * Append any text not part of this match (from the end of the |
87 | * last match). |
88 | */ |
89 | regsub_copy(&buf, &len, text, last, m[0].rm_so + start); |
90 | |
91 | /* |
92 | * If the last match was empty and this one isn't (it is either |
93 | * later or has matched text), expand this match. If it is |
94 | * empty, move on one character and try again from there. |
95 | */ |
96 | if (empty || |
97 | start + m[0].rm_so != last || |
98 | m[0].rm_so != m[0].rm_eo) { |
99 | regsub_expand(&buf, &len, with, text + start, m, |
100 | nitems(m)); |
101 | |
102 | last = start + m[0].rm_eo; |
103 | start += m[0].rm_eo; |
104 | empty = 0; |
105 | } else { |
106 | last = start + m[0].rm_eo; |
107 | start += m[0].rm_eo + 1; |
108 | empty = 1; |
109 | } |
110 | |
111 | /* Stop now if anchored to start. */ |
112 | if (*pattern == '^') { |
113 | regsub_copy(&buf, &len, text, start, end); |
114 | break; |
115 | } |
116 | } |
117 | buf[len] = '\0'; |
118 | |
119 | regfree(&r); |
120 | return (buf); |
121 | } |
122 | |