Commit | Line | Data |
---|---|---|
de609995 BJ |
1 | static char sccsid[] = "@(#)re.c 4.1 %G%"; |
2 | #include "head.h" | |
3 | #define CBRA 1 | |
4 | #define CCHR 2 | |
5 | #define CDOT 4 | |
6 | #define CCL 6 | |
7 | #define NCCL 8 | |
8 | #define CDOL 10 | |
9 | #define CEOF 11 | |
10 | #define CKET 12 | |
11 | #define CBACK 18 | |
12 | ||
13 | #define CSTAR 01 | |
14 | ||
15 | #define LBSIZE 512 | |
16 | #define ESIZE 256 | |
17 | #define NBRA 9 | |
18 | ||
19 | char expbuf[ESIZE]; | |
20 | int circf; | |
21 | char *braslist[NBRA]; | |
22 | char *braelist[NBRA]; | |
23 | char bittab[] = { | |
24 | 1, | |
25 | 2, | |
26 | 4, | |
27 | 8, | |
28 | 16, | |
29 | 32, | |
30 | 64, | |
31 | 128 | |
32 | }; | |
33 | ||
34 | dore() { | |
35 | register int line; | |
36 | register char *p; | |
37 | ||
38 | circf = 0; | |
39 | line = fline; | |
40 | compile(re); | |
41 | do { | |
42 | if (redir) fnext(); | |
43 | else fprev(); | |
44 | p = fbuf; | |
45 | while(*p++ != '\n') | |
46 | ; | |
47 | *--p = '\0'; | |
48 | if (match(fbuf)) goto l1; | |
49 | } while (fline != line); | |
50 | error("No match"); | |
51 | l1: *p = '\n'; | |
52 | fprint(); | |
53 | } | |
54 | ||
55 | ||
56 | compile(astr) | |
57 | char *astr; | |
58 | { | |
59 | register c; | |
60 | register char *ep, *sp; | |
61 | char *cstart; | |
62 | char *lastep; | |
63 | int cclcnt; | |
64 | char bracket[NBRA], *bracketp; | |
65 | int closed; | |
66 | char numbra; | |
67 | char neg; | |
68 | ||
69 | ep = expbuf; | |
70 | sp = astr; | |
71 | lastep = 0; | |
72 | bracketp = bracket; | |
73 | closed = numbra = 0; | |
74 | if (*sp == '^') { | |
75 | circf++; | |
76 | sp++; | |
77 | } | |
78 | for (;;) { | |
79 | if (ep >= &expbuf[ESIZE]) | |
80 | goto cerror; | |
81 | if ((c = *sp++) != '*') | |
82 | lastep = ep; | |
83 | switch (c) { | |
84 | ||
85 | case '\0': | |
86 | *ep++ = CEOF; | |
87 | return; | |
88 | ||
89 | case '.': | |
90 | *ep++ = CDOT; | |
91 | continue; | |
92 | ||
93 | case '*': | |
94 | if (lastep==0 || *lastep==CBRA || *lastep==CKET) | |
95 | goto defchar; | |
96 | *lastep |= CSTAR; | |
97 | continue; | |
98 | ||
99 | case '$': | |
100 | if (*sp != '\0') | |
101 | goto defchar; | |
102 | *ep++ = CDOL; | |
103 | continue; | |
104 | ||
105 | case '[': | |
106 | if(&ep[17] >= &expbuf[ESIZE]) | |
107 | goto cerror; | |
108 | *ep++ = CCL; | |
109 | neg = 0; | |
110 | if((c = *sp++) == '^') { | |
111 | neg = 1; | |
112 | c = *sp++; | |
113 | } | |
114 | cstart = sp; | |
115 | do { | |
116 | if (c=='\0') | |
117 | goto cerror; | |
118 | if (c=='-' && sp>cstart && *sp!=']') { | |
119 | for (c = sp[-2]; c<*sp; c++) | |
120 | ep[c>>3] |= bittab[c&07]; | |
121 | sp++; | |
122 | } | |
123 | ep[c>>3] |= bittab[c&07]; | |
124 | } while((c = *sp++) != ']'); | |
125 | if(neg) { | |
126 | for(cclcnt = 0; cclcnt < 16; cclcnt++) | |
127 | ep[cclcnt] ^= -1; | |
128 | ep[0] &= 0376; | |
129 | } | |
130 | ||
131 | ep += 16; | |
132 | ||
133 | continue; | |
134 | ||
135 | case '\\': | |
136 | if((c = *sp++) == '(') { | |
137 | if(numbra >= NBRA) { | |
138 | goto cerror; | |
139 | } | |
140 | *bracketp++ = numbra; | |
141 | *ep++ = CBRA; | |
142 | *ep++ = numbra++; | |
143 | continue; | |
144 | } | |
145 | if(c == ')') { | |
146 | if(bracketp <= bracket) { | |
147 | goto cerror; | |
148 | } | |
149 | *ep++ = CKET; | |
150 | *ep++ = *--bracketp; | |
151 | closed++; | |
152 | continue; | |
153 | } | |
154 | ||
155 | if(c >= '1' && c <= '9') { | |
156 | if((c -= '1') >= closed) | |
157 | goto cerror; | |
158 | *ep++ = CBACK; | |
159 | *ep++ = c; | |
160 | continue; | |
161 | } | |
162 | ||
163 | defchar: | |
164 | default: | |
165 | *ep++ = CCHR; | |
166 | *ep++ = c; | |
167 | } | |
168 | } | |
169 | cerror: | |
170 | errexit("RE error\n", (char *)NULL); | |
171 | } | |
172 | ||
173 | match(p1) | |
174 | register char *p1; { | |
175 | register char *p2; | |
176 | register c; | |
177 | p2 = expbuf; | |
178 | if (circf) { | |
179 | if (advance(p1, p2)) | |
180 | goto found; | |
181 | goto nfound; | |
182 | } | |
183 | /* fast check for first character */ | |
184 | if (*p2==CCHR) { | |
185 | c = p2[1]; | |
186 | do { | |
187 | if (*p1!=c) | |
188 | continue; | |
189 | if (advance(p1, p2)) | |
190 | goto found; | |
191 | } while (*p1++); | |
192 | goto nfound; | |
193 | } | |
194 | /* regular algorithm */ | |
195 | do { | |
196 | if (advance(p1, p2)) | |
197 | goto found; | |
198 | } while (*p1++); | |
199 | nfound: | |
200 | return(0); | |
201 | found: | |
202 | return(1); | |
203 | } | |
204 | ||
205 | advance(lp, ep) | |
206 | register char *lp, *ep; | |
207 | { | |
208 | register char *curlp; | |
209 | char c; | |
210 | char *bbeg; | |
211 | int ct; | |
212 | ||
213 | for (;;) switch (*ep++) { | |
214 | ||
215 | case CCHR: | |
216 | if (*ep++ == *lp++) | |
217 | continue; | |
218 | return(0); | |
219 | ||
220 | case CDOT: | |
221 | if (*lp++) | |
222 | continue; | |
223 | return(0); | |
224 | ||
225 | case CDOL: | |
226 | if (*lp=='\0') | |
227 | continue; | |
228 | return(0); | |
229 | ||
230 | case CEOF: | |
231 | return(1); | |
232 | ||
233 | case CCL: | |
234 | c = *lp++ & 0177; | |
235 | if(ep[c>>3] & bittab[c & 07]) { | |
236 | ep += 16; | |
237 | continue; | |
238 | } | |
239 | return(0); | |
240 | case CBRA: | |
241 | braslist[*ep++] = lp; | |
242 | continue; | |
243 | ||
244 | case CKET: | |
245 | braelist[*ep++] = lp; | |
246 | continue; | |
247 | ||
248 | case CBACK: | |
249 | bbeg = braslist[*ep]; | |
250 | if (braelist[*ep]==0) | |
251 | return(0); | |
252 | ct = braelist[*ep++] - bbeg; | |
253 | if(ecmp(bbeg, lp, ct)) { | |
254 | lp += ct; | |
255 | continue; | |
256 | } | |
257 | return(0); | |
258 | ||
259 | case CBACK|CSTAR: | |
260 | bbeg = braslist[*ep]; | |
261 | if (braelist[*ep]==0) | |
262 | return(0); | |
263 | ct = braelist[*ep++] - bbeg; | |
264 | curlp = lp; | |
265 | while(ecmp(bbeg, lp, ct)) | |
266 | lp += ct; | |
267 | while(lp >= curlp) { | |
268 | if(advance(lp, ep)) return(1); | |
269 | lp -= ct; | |
270 | } | |
271 | return(0); | |
272 | ||
273 | ||
274 | case CDOT|CSTAR: | |
275 | curlp = lp; | |
276 | while (*lp++); | |
277 | goto star; | |
278 | ||
279 | case CCHR|CSTAR: | |
280 | curlp = lp; | |
281 | while (*lp++ == *ep); | |
282 | ep++; | |
283 | goto star; | |
284 | ||
285 | case CCL|CSTAR: | |
286 | curlp = lp; | |
287 | do { | |
288 | c = *lp++ & 0177; | |
289 | } while(ep[c>>3] & bittab[c & 07]); | |
290 | ep += 16; | |
291 | goto star; | |
292 | ||
293 | star: | |
294 | if(--lp == curlp) { | |
295 | continue; | |
296 | } | |
297 | ||
298 | if(*ep == CCHR) { | |
299 | c = ep[1]; | |
300 | do { | |
301 | if(*lp != c) | |
302 | continue; | |
303 | if(advance(lp, ep)) | |
304 | return(1); | |
305 | } while(lp-- > curlp); | |
306 | return(0); | |
307 | } | |
308 | ||
309 | do { | |
310 | if (advance(lp, ep)) | |
311 | return(1); | |
312 | } while (lp-- > curlp); | |
313 | return(0); | |
314 | ||
315 | default: | |
316 | errexit("RE botch\n", (char *)NULL); | |
317 | } | |
318 | } | |
319 | ecmp(a, b, count) | |
320 | char *a, *b; | |
321 | { | |
322 | register cc = count; | |
323 | while(cc--) | |
324 | if(*a++ != *b++) return(0); | |
325 | return(1); | |
326 | } | |
327 | ||
328 | ||
329 | errexit(s) | |
330 | char *s; { | |
331 | error(s); | |
332 | return; | |
333 | } |