Function headerless_match_one_pattern

grep.c:946–1008

};

static int headerless_match_one_pattern(struct grep_pat *p,
					const char *bol, const char *eol,
					enum grep_context ctx,
					regmatch_t *pmatch, int eflags)
{
	int hit = 0;
	const char *start = bol;

	if ((p->token != GREP_PATTERN) &&
	    ((p->token == GREP_PATTERN_HEAD) != (ctx == GREP_CONTEXT_HEAD)))
		return 0;

 again:
	hit = patmatch(p, bol, eol, pmatch, eflags);
	if (hit < 0)
		hit = 0;

	if (hit && p->word_regexp) {
		if ((pmatch[0].rm_so < 0) ||
		    (eol - bol) < pmatch[0].rm_so ||
		    (pmatch[0].rm_eo < 0) ||
		    (eol - bol) < pmatch[0].rm_eo)
			die("regexp returned nonsense");

		/* Match beginning must be either beginning of the
		 * line, or at word boundary (i.e. the last char must
		 * not be a word char).  Similarly, match end must be
		 * either end of the line, or at word boundary
		 * (i.e. the next char must not be a word char).
		 */
		if ( ((pmatch[0].rm_so == 0) ||
		      !word_char(bol[pmatch[0].rm_so-1])) &&
		     ((pmatch[0].rm_eo == (eol-bol)) ||
		      !word_char(bol[pmatch[0].rm_eo])) )
			;
		else
			hit = 0;

		/* Words consist of at least one character. */
		if (pmatch->rm_so == pmatch->rm_eo)
			hit = 0;

		if (!hit && pmatch[0].rm_so + bol + 1 < eol) {
			/* There could be more than one match on the
			 * line, and the first match might not be
			 * strict word match.  But later ones could be!
			 * Forward to the next possible start, i.e. the
			 * next position following a non-word char.
			 */
			bol = pmatch[0].rm_so + bol + 1;
			while (word_char(bol[-1]) && bol < eol)
				bol++;
			eflags |= REG_NOTBOL;
			if (bol < eol)
				goto again;
		}
	}
	if (hit) {