1 #define	EXTERN
2 #include	"grep.h"
3 
4 char *validflags = "bchiLlnsv";
5 void
6 usage(void)
7 {
8 	fprint(2, "usage: grep [-%s] [-f file] [-e expr] [file ...]\n", validflags);
9 	exits("usage");
10 }
11 
12 void
13 main(int argc, char *argv[])
14 {
15 	int i, status;
16 
17 	ARGBEGIN {
18 	default:
19 		if(utfrune(validflags, ARGC()) == nil)
20 			usage();
21 		flags[ARGC()]++;
22 		break;
23 
24 	case 'E':	/* ignore, turns gnu grep into egrep */
25 		break;
26 
27 	case 'e':
28 		flags['e']++;
29 		lineno = 0;
30 		str2top(ARGF());
31 		break;
32 
33 	case 'f':
34 		flags['f']++;
35 		filename = ARGF();
36 		rein = Bopen(filename, OREAD);
37 		if(rein == 0) {
38 			fprint(2, "grep: can't open %s: %r\n", filename);
39 			exits("open");
40 		}
41 		lineno = 1;
42 		str2top(filename);
43 		break;
44 	} ARGEND
45 
46 	if(flags['f'] == 0 && flags['e'] == 0) {
47 		if(argc <= 0)
48 			usage();
49 		str2top(argv[0]);
50 		argc--;
51 		argv++;
52 	}
53 
54 	follow = mal(maxfollow*sizeof(*follow));
55 	state0 = initstate(topre.beg);
56 
57 	Binit(&bout, 1, OWRITE);
58 	switch(argc) {
59 	case 0:
60 		status = search(0, 0);
61 		break;
62 	case 1:
63 		status = search(argv[0], 0);
64 		break;
65 	default:
66 		status = 0;
67 		for(i=0; i<argc; i++)
68 			status |= search(argv[i], Hflag);
69 		break;
70 	}
71 	if(status)
72 		exits(0);
73 	exits("no matches");
74 }
75 
76 int
77 search(char *file, int flag)
78 {
79 	State *s, *ns;
80 	int c, fid, eof, nl, empty;
81 	long count, lineno, n;
82 	uchar *elp, *lp, *bol;
83 
84 	if(file == 0) {
85 		file = "stdin";
86 		fid = 0;
87 		flag |= Bflag;
88 	} else
89 		fid = open(file, OREAD);
90 
91 	if(fid < 0) {
92 		fprint(2, "grep: can't open %s: %r\n", file);
93 		return 0;
94 	}
95 
96 	if(flags['b'])
97 		flag ^= Bflag;		/* dont buffer output */
98 	if(flags['c'])
99 		flag |= Cflag;		/* count */
100 	if(flags['h'])
101 		flag &= ~Hflag;		/* do not print file name in output */
102 	if(flags['i'])
103 		flag |= Iflag;		/* fold upper-lower */
104 	if(flags['l'])
105 		flag |= Llflag;		/* print only name of file if any match */
106 	if(flags['L'])
107 		flag |= LLflag;		/* print only name of file if any non match */
108 	if(flags['n'])
109 		flag |= Nflag;		/* count only */
110 	if(flags['s'])
111 		flag |= Sflag;		/* status only */
112 	if(flags['v'])
113 		flag |= Vflag;		/* inverse match */
114 
115 	s = state0;
116 	lineno = 0;
117 	count = 0;
118 	eof = 0;
119 	empty = 1;
120 	nl = 0;
121 	lp = u.u.buf;
122 	bol = lp;
123 
124 loop0:
125 	n = lp-bol;
126 	if(n > sizeof(u.u.pre))
127 		n = sizeof(u.u.pre);
128 	memmove(u.u.buf-n, bol, n);
129 	bol = u.u.buf-n;
130 	n = read(fid, u.u.buf, sizeof(u.u.buf));
131 	/* if file has no final newline, simulate one to emit matches to last line */
132 	if(n > 0) {
133 		empty = 0;
134 		nl = u.u.buf[n-1]=='\n';
135 	} else {
136 		if(n < 0){
137 			fprint(2, "grep: read error on %s: %r\n", file);
138 			return count != 0;
139 		}
140 		if(!eof && !nl && !empty) {
141 			u.u.buf[0] = '\n';
142 			n = 1;
143 			eof = 1;
144 		}
145 	}
146 	if(n <= 0) {
147 		close(fid);
148 		if(flag & Cflag) {
149 			if(flag & Hflag)
150 				Bprint(&bout, "%s:", file);
151 			Bprint(&bout, "%ld\n", count);
152 		}
153 		if(((flag&Llflag) && count != 0) || ((flag&LLflag) && count == 0))
154 			Bprint(&bout, "%s\n", file);
155 		Bflush(&bout);
156 		return count != 0;
157 	}
158 	lp = u.u.buf;
159 	elp = lp+n;
160 	if(flag & Iflag)
161 		goto loopi;
162 
163 /*
164  * normal character loop
165  */
166 loop:
167 	c = *lp;
168 	ns = s->next[c];
169 	if(ns == 0) {
170 		increment(s, c);
171 		goto loop;
172 	}
173 /*	if(flags['2']) */
174 /*		if(s->match) */
175 /*			print("%d: %.2x**\n", s, c); */
176 /*		else */
177 /*			print("%d: %.2x\n", s, c); */
178 	lp++;
179 	s = ns;
180 	if(c == '\n') {
181 		lineno++;
182 		if(!!s->match == !(flag&Vflag)) {
183 			count++;
184 			if(flag & (Cflag|Sflag|Llflag|LLflag))
185 				goto cont;
186 			if(flag & Hflag)
187 				Bprint(&bout, "%s:", file);
188 			if(flag & Nflag)
189 				Bprint(&bout, "%ld: ", lineno);
190 			/* suppress extra newline at EOF unless we are labeling matches with file name */
191 			Bwrite(&bout, bol, lp-bol-(eof && !(flag&Hflag)));
192 			if(flag & Bflag)
193 				Bflush(&bout);
194 		}
195 		if((lineno & Flshcnt) == 0)
196 			Bflush(&bout);
197 	cont:
198 		bol = lp;
199 	}
200 	if(lp != elp)
201 		goto loop;
202 	goto loop0;
203 
204 /*
205  * character loop for -i flag
206  * for speed
207  */
208 loopi:
209 	c = *lp;
210 	if(c >= 'A' && c <= 'Z')
211 		c += 'a'-'A';
212 	ns = s->next[c];
213 	if(ns == 0) {
214 		increment(s, c);
215 		goto loopi;
216 	}
217 	lp++;
218 	s = ns;
219 	if(c == '\n') {
220 		lineno++;
221 		if(!!s->match == !(flag&Vflag)) {
222 			count++;
223 			if(flag & (Cflag|Sflag|Llflag|LLflag))
224 				goto conti;
225 			if(flag & Hflag)
226 				Bprint(&bout, "%s:", file);
227 			if(flag & Nflag)
228 				Bprint(&bout, "%ld: ", lineno);
229 			/* suppress extra newline at EOF unless we are labeling matches with file name */
230 			Bwrite(&bout, bol, lp-bol-(eof && !(flag&Hflag)));
231 			if(flag & Bflag)
232 				Bflush(&bout);
233 		}
234 		if((lineno & Flshcnt) == 0)
235 			Bflush(&bout);
236 	conti:
237 		bol = lp;
238 	}
239 	if(lp != elp)
240 		goto loopi;
241 	goto loop0;
242 }
243 
244 State*
245 initstate(Re *r)
246 {
247 	State *s;
248 	int i;
249 
250 	addcase(r);
251 	if(flags['1'])
252 		reprint("r", r);
253 	nfollow = 0;
254 	gen++;
255 	fol1(r, Cbegin);
256 	follow[nfollow++] = r;
257 	qsort(follow, nfollow, sizeof(*follow), fcmp);
258 
259 	s = sal(nfollow);
260 	for(i=0; i<nfollow; i++)
261 		s->re[i] = follow[i];
262 	return s;
263 }