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15637ed4 RG |
1 | /* regsub.c */ |
2 | ||
3 | /* This file contains the regsub() function, which performs substitutions | |
4 | * after a regexp match has been found. | |
5 | */ | |
6 | ||
7 | #include "config.h" | |
8 | #include "ctype.h" | |
9 | #include "vi.h" | |
10 | #include "regexp.h" | |
11 | ||
12 | ||
13 | /* perform substitutions after a regexp match */ | |
14 | void regsub(re, src, dst) | |
15 | regexp *re; /* the regexp with pointers into matched text */ | |
16 | REG char *src; /* the replacement string */ | |
17 | REG char *dst; /* where to put the result of the subst */ | |
18 | { | |
19 | REG char *cpy; /* pointer to start of text to copy */ | |
20 | REG char *end; /* pointer to end of text to copy */ | |
21 | REG char c; | |
22 | char *start; | |
23 | #ifndef CRUNCH | |
24 | int mod = 0;/* used to track \U, \L, \u, \l, and \E */ | |
25 | int len; /* used to calculate length of subst string */ | |
26 | static char *prev; /* a copy of the text from the previous subst */ | |
27 | ||
28 | /* replace \~ (or maybe ~) by previous substitution text */ | |
29 | ||
30 | /* step 1: calculate the length of the new substitution text */ | |
31 | for (len = strlen(src), c = '\0', cpy = src; *cpy; cpy++) | |
32 | { | |
33 | # ifdef NO_MAGIC | |
34 | if (c == '\\' && *cpy == '~') | |
35 | # else | |
36 | if (c == (*o_magic ? '\0' : '\\') && *cpy == '~') | |
37 | # endif | |
38 | { | |
39 | if (!prev) | |
40 | { | |
41 | regerror("No prev text to substitute for ~"); | |
42 | return; | |
43 | } | |
44 | len += strlen(prev) - 1; | |
45 | # ifndef NO_MAGIC | |
46 | if (!*o_magic) | |
47 | # endif | |
48 | len -= 1; /* because we lose the \ too */ | |
49 | } | |
50 | ||
51 | /* watch backslash quoting */ | |
52 | if (c != '\\' && *cpy == '\\') | |
53 | c = '\\'; | |
54 | else | |
55 | c = '\0'; | |
56 | } | |
57 | ||
58 | /* allocate memory for the ~ed version of src */ | |
59 | start = cpy = (char *)malloc((unsigned)(len + 1)); | |
60 | if (!cpy) | |
61 | { | |
62 | regerror("Not enough memory for ~ expansion"); | |
63 | return; | |
64 | } | |
65 | ||
66 | /* copy src into start, replacing the ~s by the previous text */ | |
67 | while (*src) | |
68 | { | |
69 | # ifndef NO_MAGIC | |
70 | if (*o_magic && *src == '~') | |
71 | { | |
72 | strcpy(cpy, prev); | |
73 | cpy += strlen(prev); | |
74 | src++; | |
75 | } | |
76 | else if (!*o_magic && *src == '\\' && *(src + 1) == '~') | |
77 | # else /* NO_MAGIC */ | |
78 | if (*src == '\\' && *(src + 1) == '~') | |
79 | # endif /* NO_MAGIC */ | |
80 | { | |
81 | strcpy(cpy, prev); | |
82 | cpy += strlen(prev); | |
83 | src += 2; | |
84 | } | |
85 | else | |
86 | { | |
87 | *cpy++ = *src++; | |
88 | } | |
89 | } | |
90 | *cpy = '\0'; | |
91 | #ifdef DEBUG | |
92 | if ((int)(cpy - start) != len) | |
93 | { | |
94 | msg("Bug in regsub.c! Predicted length = %d, Actual length = %d", len, (int)(cpy - start)); | |
95 | } | |
96 | #endif | |
97 | ||
98 | /* remember this as the "previous" for next time */ | |
99 | if (prev) | |
100 | free(prev); | |
101 | prev = src = start; | |
102 | ||
103 | #endif /* undef CRUNCH */ | |
104 | ||
105 | start = src; | |
106 | while ((c = *src++) != '\0') | |
107 | { | |
108 | #ifndef NO_MAGIC | |
109 | /* recognize any meta characters */ | |
110 | if (c == '&' && *o_magic) | |
111 | { | |
112 | cpy = re->startp[0]; | |
113 | end = re->endp[0]; | |
114 | } | |
115 | else | |
116 | #endif /* not NO_MAGIC */ | |
117 | if (c == '\\') | |
118 | { | |
119 | c = *src++; | |
120 | switch (c) | |
121 | { | |
122 | #ifndef NO_MAGIC | |
123 | case '0': | |
124 | case '1': | |
125 | case '2': | |
126 | case '3': | |
127 | case '4': | |
128 | case '5': | |
129 | case '6': | |
130 | case '7': | |
131 | case '8': | |
132 | case '9': | |
133 | /* \0 thru \9 mean "copy subexpression" */ | |
134 | c -= '0'; | |
135 | cpy = re->startp[c]; | |
136 | end = re->endp[c]; | |
137 | break; | |
138 | # ifndef CRUNCH | |
139 | case 'U': | |
140 | case 'u': | |
141 | case 'L': | |
142 | case 'l': | |
143 | /* \U and \L mean "convert to upper/lowercase" */ | |
144 | mod = c; | |
145 | continue; | |
146 | ||
147 | case 'E': | |
148 | case 'e': | |
149 | /* \E ends the \U or \L */ | |
150 | mod = 0; | |
151 | continue; | |
152 | # endif /* not CRUNCH */ | |
153 | case '&': | |
154 | /* "\&" means "original text" */ | |
155 | if (*o_magic) | |
156 | { | |
157 | *dst++ = c; | |
158 | continue; | |
159 | } | |
160 | cpy = re->startp[0]; | |
161 | end = re->endp[0]; | |
162 | break; | |
163 | ||
164 | #else /* NO_MAGIC */ | |
165 | case '&': | |
166 | /* "\&" means "original text" */ | |
167 | cpy = re->startp[0]; | |
168 | end = re->endp[0]; | |
169 | break; | |
170 | #endif /* NO_MAGIC */ | |
171 | default: | |
172 | /* ordinary char preceded by backslash */ | |
173 | *dst++ = c; | |
174 | continue; | |
175 | } | |
176 | } | |
177 | #ifndef CRUNCH | |
178 | # if OSK | |
179 | else if (c == '\l') | |
180 | # else | |
181 | else if (c == '\r') | |
182 | # endif | |
183 | { | |
184 | /* transliterate ^M into newline */ | |
185 | *dst++ = '\n'; | |
186 | continue; | |
187 | } | |
188 | #endif /* !CRUNCH */ | |
189 | else | |
190 | { | |
191 | /* ordinary character, so just copy it */ | |
192 | *dst++ = c; | |
193 | continue; | |
194 | } | |
195 | ||
196 | /* Note: to reach this point in the code, we must have evaded | |
197 | * all "continue" statements. To do that, we must have hit | |
198 | * a metacharacter that involves copying. | |
199 | */ | |
200 | ||
201 | /* if there is nothing to copy, loop */ | |
202 | if (!cpy) | |
203 | continue; | |
204 | ||
205 | /* copy over a portion of the original */ | |
206 | while (cpy < end) | |
207 | { | |
208 | #ifndef NO_MAGIC | |
209 | # ifndef CRUNCH | |
210 | switch (mod) | |
211 | { | |
212 | case 'U': | |
213 | case 'u': | |
214 | /* convert to uppercase */ | |
215 | *dst++ = toupper(*cpy++); | |
216 | break; | |
217 | ||
218 | case 'L': | |
219 | case 'l': | |
220 | /* convert to lowercase */ | |
221 | *dst++ = tolower(*cpy++); | |
222 | break; | |
223 | ||
224 | default: | |
225 | /* copy without any conversion */ | |
226 | *dst++ = *cpy++; | |
227 | } | |
228 | ||
229 | /* \u and \l end automatically after the first char */ | |
230 | if (mod && (mod == 'u' || mod == 'l')) | |
231 | { | |
232 | mod = 0; | |
233 | } | |
234 | # else /* CRUNCH */ | |
235 | *dst++ = *cpy++; | |
236 | # endif /* CRUNCH */ | |
237 | #else /* NO_MAGIC */ | |
238 | *dst++ = *cpy++; | |
239 | #endif /* NO_MAGIC */ | |
240 | } | |
241 | } | |
242 | *dst = '\0'; | |
243 | } |