1 |
greg |
1.1 |
#ifndef lint |
2 |
schorsch |
2.9 |
static const char RCSid[] = "$Id: rexpr.c,v 2.8 2003/06/30 14:59:11 schorsch Exp $"; |
3 |
greg |
1.1 |
#endif |
4 |
greg |
2.4 |
/* |
5 |
|
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* Regular expression parsing routines. |
6 |
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* |
7 |
|
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* External symbols declared in standard.h |
8 |
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*/ |
9 |
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10 |
greg |
2.5 |
#include "copyright.h" |
11 |
greg |
1.1 |
|
12 |
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#include <stdio.h> |
13 |
greg |
2.4 |
#include <stdlib.h> |
14 |
greg |
1.1 |
#include <ctype.h> |
15 |
schorsch |
2.7 |
#include <string.h> |
16 |
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|
17 |
schorsch |
2.9 |
#include "rtio.h" |
18 |
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|
19 |
greg |
1.1 |
/* |
20 |
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* rexpr.c - regular expression parser (ala grep) |
21 |
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*/ |
22 |
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23 |
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#define CCHR 2 |
24 |
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#define CDOT 4 |
25 |
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#define CCL 6 |
26 |
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#define NCCL 8 |
27 |
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#define CDOL 10 |
28 |
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#define CEOF 11 |
29 |
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#define CBRC 14 |
30 |
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#define CLET 15 |
31 |
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#define STAR 01 |
32 |
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33 |
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#define ESIZE 255 |
34 |
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35 |
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#define same(a,b) (a==b || (iflag && (a^b)==' ' && isalpha(a))) |
36 |
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37 |
greg |
1.2 |
|
38 |
schorsch |
2.9 |
static int advance(char *, char *); |
39 |
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static int cclass(char *, int c, int af); |
40 |
greg |
1.4 |
|
41 |
greg |
1.1 |
static char expbuf[ESIZE]; |
42 |
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static int iflag; |
43 |
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static int circf; |
44 |
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45 |
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int explen; /* length of the last expression found */ |
46 |
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47 |
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int |
48 |
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ecompile(sp, iflg, wflag) /* compile the expression */ |
49 |
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register char *sp; |
50 |
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int iflg, wflag; |
51 |
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{ |
52 |
schorsch |
2.9 |
register int c; |
53 |
greg |
1.1 |
register char *ep; |
54 |
schorsch |
2.9 |
char *lastep = NULL; |
55 |
greg |
1.1 |
int cclcnt; |
56 |
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57 |
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iflag = iflg; |
58 |
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ep = expbuf; |
59 |
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explen = 0; |
60 |
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if (*sp == '^') { |
61 |
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circf = 1; |
62 |
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sp++; |
63 |
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} else |
64 |
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circf = 0; |
65 |
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if (wflag) |
66 |
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*ep++ = CBRC; |
67 |
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for (;;) { |
68 |
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if (ep >= &expbuf[ESIZE]) |
69 |
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return(-1); |
70 |
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if ((c = *sp++) != '*') |
71 |
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lastep = ep; |
72 |
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switch (c) { |
73 |
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74 |
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case '\0': |
75 |
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if (wflag) |
76 |
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*ep++ = CLET; |
77 |
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*ep++ = CEOF; |
78 |
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explen = ep - expbuf; |
79 |
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return(0); |
80 |
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81 |
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case '.': |
82 |
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*ep++ = CDOT; |
83 |
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continue; |
84 |
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85 |
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case '*': |
86 |
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if (lastep==0) |
87 |
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goto defchar; |
88 |
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*lastep |= STAR; |
89 |
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continue; |
90 |
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91 |
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case '$': |
92 |
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if (*sp != '\0') |
93 |
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goto defchar; |
94 |
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*ep++ = CDOL; |
95 |
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continue; |
96 |
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97 |
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case '[': |
98 |
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*ep++ = CCL; |
99 |
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*ep++ = 0; |
100 |
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cclcnt = 1; |
101 |
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if ((c = *sp++) == '^') { |
102 |
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c = *sp++; |
103 |
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ep[-2] = NCCL; |
104 |
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} |
105 |
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do { |
106 |
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*ep++ = c; |
107 |
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cclcnt++; |
108 |
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if (c=='\0' || ep >= &expbuf[ESIZE]) |
109 |
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return(-1); |
110 |
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} while ((c = *sp++) != ']'); |
111 |
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lastep[1] = cclcnt; |
112 |
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continue; |
113 |
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114 |
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case '\\': |
115 |
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if ((c = *sp++) == '\0') |
116 |
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return(-1); |
117 |
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if (c == '<') { |
118 |
greg |
2.2 |
if (ep == expbuf || ep[-1] != CBRC) |
119 |
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*ep++ = CBRC; |
120 |
greg |
1.1 |
continue; |
121 |
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} |
122 |
|
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if (c == '>') { |
123 |
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*ep++ = CLET; |
124 |
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continue; |
125 |
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} |
126 |
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defchar: |
127 |
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default: |
128 |
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*ep++ = CCHR; |
129 |
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*ep++ = c; |
130 |
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} |
131 |
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} |
132 |
|
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} |
133 |
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134 |
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char * |
135 |
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expsave() /* save compiled string */ |
136 |
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{ |
137 |
|
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register char *ep; |
138 |
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|
139 |
|
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if (explen == 0) |
140 |
|
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return(NULL); |
141 |
greg |
2.4 |
if ((ep = (char *)malloc(explen+3)) == NULL) |
142 |
greg |
1.1 |
return(NULL); |
143 |
|
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ep[0] = iflag; |
144 |
|
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ep[1] = circf; |
145 |
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ep[2] = explen; |
146 |
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(void)memcpy(ep+3, expbuf, explen); |
147 |
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return(ep); |
148 |
|
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} |
149 |
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|
150 |
greg |
2.4 |
void |
151 |
greg |
1.1 |
expset(ep) /* install saved string */ |
152 |
|
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register char *ep; |
153 |
|
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{ |
154 |
|
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iflag = ep[0]; |
155 |
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circf = ep[1]; |
156 |
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(void)memcpy(expbuf, ep+3, ep[2]&0xff); |
157 |
|
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} |
158 |
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|
159 |
|
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char * |
160 |
greg |
2.2 |
eindex(sp) /* find the expression in string sp */ |
161 |
greg |
1.1 |
register char *sp; |
162 |
|
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{ |
163 |
greg |
2.2 |
/* check for match at beginning of line, watch CBRC */ |
164 |
|
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if (advance(sp, expbuf[0]==CBRC ? expbuf+1 : expbuf)) |
165 |
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return(sp); |
166 |
|
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if (circf) |
167 |
greg |
1.1 |
return(NULL); |
168 |
|
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/* fast check for first character */ |
169 |
|
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if (expbuf[0]==CCHR) { |
170 |
schorsch |
2.9 |
register int c = expbuf[1]; |
171 |
greg |
2.2 |
while (*++sp) |
172 |
greg |
1.1 |
if (same(*sp, c) && advance(sp, expbuf)) |
173 |
|
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return(sp); |
174 |
|
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return(NULL); |
175 |
|
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} |
176 |
|
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/* regular algorithm */ |
177 |
greg |
2.2 |
while (*++sp) |
178 |
greg |
1.1 |
if (advance(sp, expbuf)) |
179 |
|
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return(sp); |
180 |
|
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return(NULL); |
181 |
|
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} |
182 |
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|
183 |
|
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static int |
184 |
|
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advance(alp, ep) |
185 |
|
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char *alp; |
186 |
|
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register char *ep; |
187 |
|
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{ |
188 |
|
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register char *lp; |
189 |
|
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char *curlp; |
190 |
|
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|
191 |
|
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lp = alp; |
192 |
|
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for (;;) switch (*ep++) { |
193 |
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194 |
|
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case CCHR: |
195 |
|
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if (!same(*ep, *lp)) |
196 |
|
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return (0); |
197 |
|
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ep++, lp++; |
198 |
|
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continue; |
199 |
|
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|
200 |
|
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case CDOT: |
201 |
|
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if (*lp++) |
202 |
|
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continue; |
203 |
|
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return(0); |
204 |
|
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|
205 |
|
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case CDOL: |
206 |
|
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if (*lp==0) |
207 |
|
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continue; |
208 |
|
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return(0); |
209 |
|
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|
210 |
|
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case CEOF: |
211 |
|
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explen = lp - alp; |
212 |
|
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return(1); |
213 |
|
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|
214 |
|
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case CCL: |
215 |
|
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if (cclass(ep, *lp++, 1)) { |
216 |
|
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ep += *ep; |
217 |
|
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continue; |
218 |
|
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} |
219 |
|
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return(0); |
220 |
|
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|
221 |
|
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case NCCL: |
222 |
|
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if (cclass(ep, *lp++, 0)) { |
223 |
|
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ep += *ep; |
224 |
|
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continue; |
225 |
|
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} |
226 |
|
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return(0); |
227 |
|
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|
228 |
|
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case CDOT|STAR: |
229 |
|
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curlp = lp; |
230 |
|
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while (*lp++); |
231 |
|
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goto star; |
232 |
|
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|
233 |
|
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case CCHR|STAR: |
234 |
|
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curlp = lp; |
235 |
|
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while (same(*lp, *ep)) |
236 |
|
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lp++; |
237 |
|
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lp++; |
238 |
|
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ep++; |
239 |
|
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goto star; |
240 |
|
|
|
241 |
|
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case CCL|STAR: |
242 |
|
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case NCCL|STAR: |
243 |
|
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curlp = lp; |
244 |
|
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while (cclass(ep, *lp++, ep[-1]==(CCL|STAR))); |
245 |
|
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ep += *ep; |
246 |
|
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star: |
247 |
|
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do { |
248 |
|
|
lp--; |
249 |
|
|
if (advance(lp, ep)) { |
250 |
|
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explen += lp - alp; |
251 |
|
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return(1); |
252 |
|
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} |
253 |
|
|
} while (lp > curlp); |
254 |
|
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return(0); |
255 |
|
|
|
256 |
|
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case CBRC: |
257 |
|
|
if ((isalnum(*lp) || *lp == '_') && !(isalnum(lp[-1]) || lp[-1] == '_')) |
258 |
|
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continue; |
259 |
|
|
return (0); |
260 |
|
|
|
261 |
|
|
case CLET: |
262 |
|
|
if (!isalnum(*lp) && *lp != '_') |
263 |
|
|
continue; |
264 |
|
|
return (0); |
265 |
|
|
|
266 |
|
|
default: |
267 |
|
|
fprintf(stderr, "RE botch\n"); |
268 |
|
|
} |
269 |
|
|
} |
270 |
|
|
|
271 |
|
|
static int |
272 |
|
|
cclass(set, c, af) |
273 |
|
|
register char *set; |
274 |
schorsch |
2.9 |
register int c; |
275 |
greg |
2.3 |
int af; |
276 |
greg |
1.1 |
{ |
277 |
schorsch |
2.9 |
register int n; |
278 |
greg |
1.1 |
|
279 |
|
|
if (c == 0) |
280 |
|
|
return(0); |
281 |
|
|
n = *set++; |
282 |
|
|
while (--n) |
283 |
|
|
if (n > 2 && set[1] == '-') { |
284 |
|
|
if (c >= set[0] && c <= set[2]) |
285 |
|
|
return (af); |
286 |
|
|
set += 3; |
287 |
|
|
n -= 2; |
288 |
|
|
} else |
289 |
|
|
if (*set++ == c) |
290 |
|
|
return(af); |
291 |
|
|
return(!af); |
292 |
|
|
} |