| 1 |
/* Copyright (c) 1990 Regents of the University of California */ |
| 2 |
|
| 3 |
#ifndef lint |
| 4 |
static char SCCSid[] = "$SunId$ LBL"; |
| 5 |
#endif |
| 6 |
|
| 7 |
#include <stdio.h> |
| 8 |
#include <ctype.h> |
| 9 |
/* |
| 10 |
* rexpr.c - regular expression parser (ala grep) |
| 11 |
*/ |
| 12 |
|
| 13 |
#define CCHR 2 |
| 14 |
#define CDOT 4 |
| 15 |
#define CCL 6 |
| 16 |
#define NCCL 8 |
| 17 |
#define CDOL 10 |
| 18 |
#define CEOF 11 |
| 19 |
#define CBRC 14 |
| 20 |
#define CLET 15 |
| 21 |
#define STAR 01 |
| 22 |
|
| 23 |
#define ESIZE 255 |
| 24 |
|
| 25 |
#define same(a,b) (a==b || (iflag && (a^b)==' ' && isalpha(a))) |
| 26 |
|
| 27 |
#ifdef BSD |
| 28 |
#define memcpy(to,from,len) bcopy(from,to,len) |
| 29 |
#endif |
| 30 |
|
| 31 |
static int advance(), cclass(); |
| 32 |
|
| 33 |
static char expbuf[ESIZE]; |
| 34 |
static int iflag; |
| 35 |
static int circf; |
| 36 |
|
| 37 |
int explen; /* length of the last expression found */ |
| 38 |
|
| 39 |
int |
| 40 |
ecompile(sp, iflg, wflag) /* compile the expression */ |
| 41 |
register char *sp; |
| 42 |
int iflg, wflag; |
| 43 |
{ |
| 44 |
register c; |
| 45 |
register char *ep; |
| 46 |
char *lastep; |
| 47 |
int cclcnt; |
| 48 |
|
| 49 |
iflag = iflg; |
| 50 |
ep = expbuf; |
| 51 |
explen = 0; |
| 52 |
if (*sp == '^') { |
| 53 |
circf = 1; |
| 54 |
sp++; |
| 55 |
} else |
| 56 |
circf = 0; |
| 57 |
if (wflag) |
| 58 |
*ep++ = CBRC; |
| 59 |
for (;;) { |
| 60 |
if (ep >= &expbuf[ESIZE]) |
| 61 |
return(-1); |
| 62 |
if ((c = *sp++) != '*') |
| 63 |
lastep = ep; |
| 64 |
switch (c) { |
| 65 |
|
| 66 |
case '\0': |
| 67 |
if (wflag) |
| 68 |
*ep++ = CLET; |
| 69 |
*ep++ = CEOF; |
| 70 |
explen = ep - expbuf; |
| 71 |
return(0); |
| 72 |
|
| 73 |
case '.': |
| 74 |
*ep++ = CDOT; |
| 75 |
continue; |
| 76 |
|
| 77 |
case '*': |
| 78 |
if (lastep==0) |
| 79 |
goto defchar; |
| 80 |
*lastep |= STAR; |
| 81 |
continue; |
| 82 |
|
| 83 |
case '$': |
| 84 |
if (*sp != '\0') |
| 85 |
goto defchar; |
| 86 |
*ep++ = CDOL; |
| 87 |
continue; |
| 88 |
|
| 89 |
case '[': |
| 90 |
*ep++ = CCL; |
| 91 |
*ep++ = 0; |
| 92 |
cclcnt = 1; |
| 93 |
if ((c = *sp++) == '^') { |
| 94 |
c = *sp++; |
| 95 |
ep[-2] = NCCL; |
| 96 |
} |
| 97 |
do { |
| 98 |
*ep++ = c; |
| 99 |
cclcnt++; |
| 100 |
if (c=='\0' || ep >= &expbuf[ESIZE]) |
| 101 |
return(-1); |
| 102 |
} while ((c = *sp++) != ']'); |
| 103 |
lastep[1] = cclcnt; |
| 104 |
continue; |
| 105 |
|
| 106 |
case '\\': |
| 107 |
if ((c = *sp++) == '\0') |
| 108 |
return(-1); |
| 109 |
if (c == '<') { |
| 110 |
if (ep == expbuf || ep[-1] != CBRC) |
| 111 |
*ep++ = CBRC; |
| 112 |
continue; |
| 113 |
} |
| 114 |
if (c == '>') { |
| 115 |
*ep++ = CLET; |
| 116 |
continue; |
| 117 |
} |
| 118 |
defchar: |
| 119 |
default: |
| 120 |
*ep++ = CCHR; |
| 121 |
*ep++ = c; |
| 122 |
} |
| 123 |
} |
| 124 |
} |
| 125 |
|
| 126 |
char * |
| 127 |
expsave() /* save compiled string */ |
| 128 |
{ |
| 129 |
extern char *malloc(); |
| 130 |
register char *ep; |
| 131 |
|
| 132 |
if (explen == 0) |
| 133 |
return(NULL); |
| 134 |
if ((ep = malloc(explen+3)) == NULL) |
| 135 |
return(NULL); |
| 136 |
ep[0] = iflag; |
| 137 |
ep[1] = circf; |
| 138 |
ep[2] = explen; |
| 139 |
(void)memcpy(ep+3, expbuf, explen); |
| 140 |
return(ep); |
| 141 |
} |
| 142 |
|
| 143 |
expset(ep) /* install saved string */ |
| 144 |
register char *ep; |
| 145 |
{ |
| 146 |
iflag = ep[0]; |
| 147 |
circf = ep[1]; |
| 148 |
(void)memcpy(expbuf, ep+3, ep[2]&0xff); |
| 149 |
} |
| 150 |
|
| 151 |
char * |
| 152 |
eindex(sp) /* find the expression in string sp */ |
| 153 |
register char *sp; |
| 154 |
{ |
| 155 |
/* check for match at beginning of line, watch CBRC */ |
| 156 |
if (advance(sp, expbuf[0]==CBRC ? expbuf+1 : expbuf)) |
| 157 |
return(sp); |
| 158 |
if (circf) |
| 159 |
return(NULL); |
| 160 |
/* fast check for first character */ |
| 161 |
if (expbuf[0]==CCHR) { |
| 162 |
register c = expbuf[1]; |
| 163 |
while (*++sp) |
| 164 |
if (same(*sp, c) && advance(sp, expbuf)) |
| 165 |
return(sp); |
| 166 |
return(NULL); |
| 167 |
} |
| 168 |
/* regular algorithm */ |
| 169 |
while (*++sp) |
| 170 |
if (advance(sp, expbuf)) |
| 171 |
return(sp); |
| 172 |
return(NULL); |
| 173 |
} |
| 174 |
|
| 175 |
static int |
| 176 |
advance(alp, ep) |
| 177 |
char *alp; |
| 178 |
register char *ep; |
| 179 |
{ |
| 180 |
register char *lp; |
| 181 |
char *curlp; |
| 182 |
|
| 183 |
lp = alp; |
| 184 |
for (;;) switch (*ep++) { |
| 185 |
|
| 186 |
case CCHR: |
| 187 |
if (!same(*ep, *lp)) |
| 188 |
return (0); |
| 189 |
ep++, lp++; |
| 190 |
continue; |
| 191 |
|
| 192 |
case CDOT: |
| 193 |
if (*lp++) |
| 194 |
continue; |
| 195 |
return(0); |
| 196 |
|
| 197 |
case CDOL: |
| 198 |
if (*lp==0) |
| 199 |
continue; |
| 200 |
return(0); |
| 201 |
|
| 202 |
case CEOF: |
| 203 |
explen = lp - alp; |
| 204 |
return(1); |
| 205 |
|
| 206 |
case CCL: |
| 207 |
if (cclass(ep, *lp++, 1)) { |
| 208 |
ep += *ep; |
| 209 |
continue; |
| 210 |
} |
| 211 |
return(0); |
| 212 |
|
| 213 |
case NCCL: |
| 214 |
if (cclass(ep, *lp++, 0)) { |
| 215 |
ep += *ep; |
| 216 |
continue; |
| 217 |
} |
| 218 |
return(0); |
| 219 |
|
| 220 |
case CDOT|STAR: |
| 221 |
curlp = lp; |
| 222 |
while (*lp++); |
| 223 |
goto star; |
| 224 |
|
| 225 |
case CCHR|STAR: |
| 226 |
curlp = lp; |
| 227 |
while (same(*lp, *ep)) |
| 228 |
lp++; |
| 229 |
lp++; |
| 230 |
ep++; |
| 231 |
goto star; |
| 232 |
|
| 233 |
case CCL|STAR: |
| 234 |
case NCCL|STAR: |
| 235 |
curlp = lp; |
| 236 |
while (cclass(ep, *lp++, ep[-1]==(CCL|STAR))); |
| 237 |
ep += *ep; |
| 238 |
star: |
| 239 |
do { |
| 240 |
lp--; |
| 241 |
if (advance(lp, ep)) { |
| 242 |
explen += lp - alp; |
| 243 |
return(1); |
| 244 |
} |
| 245 |
} while (lp > curlp); |
| 246 |
return(0); |
| 247 |
|
| 248 |
case CBRC: |
| 249 |
if ((isalnum(*lp) || *lp == '_') && !(isalnum(lp[-1]) || lp[-1] == '_')) |
| 250 |
continue; |
| 251 |
return (0); |
| 252 |
|
| 253 |
case CLET: |
| 254 |
if (!isalnum(*lp) && *lp != '_') |
| 255 |
continue; |
| 256 |
return (0); |
| 257 |
|
| 258 |
default: |
| 259 |
fprintf(stderr, "RE botch\n"); |
| 260 |
} |
| 261 |
} |
| 262 |
|
| 263 |
static int |
| 264 |
cclass(set, c, af) |
| 265 |
register char *set; |
| 266 |
register c; |
| 267 |
int af; |
| 268 |
{ |
| 269 |
register n; |
| 270 |
|
| 271 |
if (c == 0) |
| 272 |
return(0); |
| 273 |
n = *set++; |
| 274 |
while (--n) |
| 275 |
if (n > 2 && set[1] == '-') { |
| 276 |
if (c >= set[0] && c <= set[2]) |
| 277 |
return (af); |
| 278 |
set += 3; |
| 279 |
n -= 2; |
| 280 |
} else |
| 281 |
if (*set++ == c) |
| 282 |
return(af); |
| 283 |
return(!af); |
| 284 |
} |
