1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
16  * 3. Neither the name of the University nor the names of its contributors
48 /*  STRNCMP -	like strncmp except that we convert the
58 		if (*s2 - makelower(*s1))  in STRNCMP()
59 			return (*s2 - makelower(*s1));  in STRNCMP()
64 	    while (--len);  in STRNCMP()
67 		if (*s2 - *s1)  in STRNCMP()
68 			return (*s2 - *s1);  in STRNCMP()
73 	    while (--len);  in STRNCMP()
114 #define ONEXT(A) (A+3)		/* next character after the operation */
144     cre = malloc(4 * strlen(re) + 3);  in convexp()
162     register char *cs;		/* pointer to current symbol in converted exp */  in expconv()  local
169     cs = NULL;  in expconv()
178 		if (cs == NULL || (*cs & STR) == 0) {  in expconv()
179 		    cs = ccre;  in expconv()
180 		    *cs = STR;  in expconv()
181 		    SCNT(cs) = 1;  in expconv()
184 		    SCNT(cs)++;  in expconv()
193 		if (acs != NULL && acs != cs) {  in expconv()
196 			OCNT(acs) = ccre - acs;  in expconv()
197 			acs -= temp;  in expconv()
201 		cs = ccre;  in expconv()
202 		*cs = META;  in expconv()
203 		MSYM(cs) = c;  in expconv()
204 		ccre = MNEXT(cs);  in expconv()
212 	    if (acs != NULL && acs != cs) {  in expconv()
215 		    OCNT(acs) = ccre - acs;  in expconv()
216 		    acs -= temp;  in expconv()
220 	    cs = ccre;  in expconv()
221 	    *cs = META;  in expconv()
222 	    MSYM(cs) = c;  in expconv()
223 	    ccre = MNEXT(cs);  in expconv()
228 	    if (cs)  in expconv()
229 	    	*cs = *cs | OPT;  in expconv()
234 	    if (acs != NULL && acs != cs) {  in expconv()
237 		    OCNT(acs) = ccre - acs;  in expconv()
238 		    acs -= temp;  in expconv()
242 	    cs = ccre;  in expconv()
243 	    *cs = OPER;  in expconv()
244 	    OSYM(cs) = '(';  in expconv()
245 	    ccre = ONEXT(cs);  in expconv()
247 	    OCNT(cs) = ccre - cs;		/* offset to next symbol */  in expconv()
255 		    OCNT(acs) = ccre - acs;  in expconv()
256 		    acs -= temp;  in expconv()
260 	    cs = ccre;  in expconv()
261 	    *cs = META;  in expconv()
262 	    MSYM(cs) = c;  in expconv()
263 	    ccre = MNEXT(cs);  in expconv()
270 	    if (acs != NULL && acs != cs)  in expconv()
271 		OCNT(ccre) = ccre - acs;	/* make a back pointer */  in expconv()
274 	    *cs |= ALT;  in expconv()
275 	    cs = ccre;  in expconv()
276 	    *cs = OPER;  in expconv()
277 	    OSYM(cs) = '|';  in expconv()
278 	    ccre = ONEXT(cs);  in expconv()
279 	    acs = cs;	/* remember that the pointer is to be filles */  in expconv()
284 	    if (cs == NULL || (*cs & STR) == 0) {  in expconv()
285 		cs = ccre;  in expconv()
286 		*cs = STR;  in expconv()
287 		SCNT(cs) = 1;  in expconv()
288 		ccre = SSTR(cs);  in expconv()
290 		SCNT(cs)++;  in expconv()
298 	    OCNT(acs) = ccre - acs;  in expconv()
299 	    acs -= temp;  in expconv()
312  *		\?	-	means last match was optional
313  *		\a	-	matches any number of characters
314  *		\d	-	matches any number of spaces and tabs
315  *		\p	-	matches any number of alphanumeric
319  *		\|	-	alternation
320  *		\( \)	-	grouping used mostly for alternation and
338     register char *cs;		/* the current symbol */  in expmatch()  local
345     cs = re;  in expmatch()
349     while (*cs) {  in expmatch()
350 	switch (*cs & (OPER | STR | META)) {  in expmatch()
354 	    matched = !STRNCMP (s, SSTR(cs), SCNT(cs));  in expmatch()
358 		s += SCNT(cs);  in expmatch()
359 		cs = SNEXT(cs);  in expmatch()
360 	    } else if (*cs & ALT) {  in expmatch()
363 		cs = SNEXT(cs);  in expmatch()
364 	    } else if (*cs & OPT) {  in expmatch()
367 		cs = SNEXT(cs);  in expmatch()
378 	    switch (OSYM(cs)) {  in expmatch()
385 		    cs = OPTR(cs);  in expmatch()
389 		    cs = ONEXT(cs);  in expmatch()
394 		ptr = expmatch(s, ONEXT(cs), mstring);  in expmatch()
400 		} else if (*cs & ALT) {  in expmatch()
404 		} else if (*cs & OPT) {  in expmatch()
413 		cs = OPTR(cs);  in expmatch()
420 	    switch (MSYM(cs)) {  in expmatch()
431 		    ptr = expmatch(s1, MNEXT(cs), mstring);  in expmatch()
435 			strncpy (mstring, s, s1 - s);  in expmatch()
436 			mstring[s1 - s] = '\0';  in expmatch()
438 		    } else if (ptr != NULL && (*cs & OPT)) {  in expmatch()
470 		    ptr = expmatch(s1, MNEXT(cs), mstring);  in expmatch()
475 		    } else if (ptr != NULL && (*cs & OPT)) {  in expmatch()
495 		cs = MNEXT(cs);  in expmatch()
507 		    cs = MNEXT(cs);  in expmatch()
512 		    cs = MNEXT(cs);  in expmatch()
513 		} else if (*cs & ALT) {  in expmatch()
517 		    cs = MNEXT(cs);  in expmatch()
518 		} else if (*cs & OPT) {  in expmatch()
522 		    cs = MNEXT(cs);  in expmatch()
536 		    cs = MNEXT(cs);  in expmatch()
537 		} else if (*cs & ALT) {  in expmatch()
541 		    cs = MNEXT(cs);  in expmatch()
542 		} else if (*cs & OPT) {  in expmatch()
546 		    cs = MNEXT(cs);  in expmatch()
559 		    cs = MNEXT(cs);  in expmatch()
560 		} else if (*cs & ALT) {  in expmatch()
564 		    cs = MNEXT(cs);  in expmatch()
565 		} else if (*cs & OPT) {  in expmatch()
569 		    cs = MNEXT(cs);  in expmatch()