1 /* grep.c - print lines what match given regular expression
2 *
3 * Copyright 2013 CE Strake <strake888 at gmail.com>
4 *
5 * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html
6 *
7 * TODO: -ABC
8
9 USE_GREP(NEWTOY(grep, "C#B#A#ZzEFHabhinorsvwclqe*f*m#x[!wx][!EFw]", TOYFLAG_BIN))
10 USE_EGREP(OLDTOY(egrep, grep, TOYFLAG_BIN))
11 USE_FGREP(OLDTOY(fgrep, grep, TOYFLAG_BIN))
12
13 config GREP
14 bool "grep"
15 default y
16 help
17 usage: grep [-EFivwcloqsHbhn] [-A NUM] [-m MAX] [-e REGEX]... [-f REGFILE] [FILE]...
18
19 Show lines matching regular expressions. If no -e, first argument is
20 regular expression to match. With no files (or "-" filename) read stdin.
21 Returns 0 if matched, 1 if no match found.
22
23 -e Regex to match. (May be repeated.)
24 -f File containing regular expressions to match.
25
26 match type:
27 -A Show NUM lines after -B Show NUM lines before match
28 -C NUM lines context (A+B) -E extended regex syntax
29 -F fixed (literal match) -i case insensitive
30 -m match MAX many lines -r recursive (on dir)
31 -v invert match -w whole word (implies -E)
32 -x whole line -z input NUL terminated
33
34 display modes: (default: matched line)
35 -c count of matching lines -l show matching filenames
36 -o only matching part -q quiet (errors only)
37 -s silent (no error msg) -Z output NUL terminated
38
39 output prefix (default: filename if checking more than 1 file)
40 -H force filename -b byte offset of match
41 -h hide filename -n line number of match
42
43 config EGREP
44 bool
45 default y
46 depends on GREP
47
48 config FGREP
49 bool
50 default y
51 depends on GREP
52 */
53
54 #define FOR_grep
55 #include "toys.h"
56 #include <regex.h>
57
GLOBALS(long m;struct arg_list * f;struct arg_list * e;long a;long b;long c;char indelim,outdelim;)58 GLOBALS(
59 long m;
60 struct arg_list *f;
61 struct arg_list *e;
62 long a;
63 long b;
64 long c;
65
66 char indelim, outdelim;
67 )
68
69 // Emit line with various potential prefixes and delimiter
70 static void outline(char *line, char dash, char *name, long lcount, long bcount,
71 int trim)
72 {
73 if (name && (toys.optflags&FLAG_H)) printf("%s%c", name, dash);
74 if (!line || (lcount && (toys.optflags&FLAG_n)))
75 printf("%ld%c", lcount, line ? dash : TT.outdelim);
76 if (bcount && (toys.optflags&FLAG_b)) printf("%ld%c", bcount-1, dash);
77 if (line) xprintf("%.*s%c", trim ? trim : INT_MAX/2, line, TT.outdelim);
78 }
79
80 // Show matches in one file
do_grep(int fd,char * name)81 static void do_grep(int fd, char *name)
82 {
83 struct double_list *dlb = 0;
84 FILE *file = fdopen(fd, "r");
85 long lcount = 0, mcount = 0, offset = 0, after = 0, before = 0;
86 char *bars = 0;
87
88 if (!fd) name = "(standard input)";
89
90 if (!file) {
91 perror_msg_raw(name);
92 return;
93 }
94
95 // Loop through lines of input
96 for (;;) {
97 char *line = 0, *start;
98 regmatch_t matches;
99 size_t unused;
100 long len;
101 int mmatch = 0;
102
103 lcount++;
104 if (0 > (len = getdelim(&line, &unused, TT.indelim, file))) break;
105 if (line[len-1] == TT.indelim) line[len-1] = 0;
106
107 start = line;
108
109 // Loop through matches in this line
110 do {
111 int rc = 0, skip = 0;
112
113 // Handle non-regex matches
114 if (toys.optflags & FLAG_F) {
115 struct arg_list *seek, fseek;
116 char *s = 0;
117
118 for (seek = TT.e; seek; seek = seek->next) {
119 if (toys.optflags & FLAG_x) {
120 int i = (toys.optflags & FLAG_i);
121
122 if ((i ? strcasecmp : strcmp)(seek->arg, line)) s = line;
123 } else if (!*seek->arg) {
124 seek = &fseek;
125 fseek.arg = s = line;
126 break;
127 }
128 if (toys.optflags & FLAG_i) s = strnstr(line, seek->arg);
129 else s = strstr(line, seek->arg);
130 if (s) break;
131 }
132
133 if (s) {
134 matches.rm_so = (s-line);
135 skip = matches.rm_eo = (s-line)+strlen(seek->arg);
136 } else rc = 1;
137 } else {
138 rc = regexec((regex_t *)toybuf, start, 1, &matches,
139 start==line ? 0 : REG_NOTBOL);
140 skip = matches.rm_eo;
141 }
142
143 if (toys.optflags & FLAG_x)
144 if (matches.rm_so || line[matches.rm_eo]) rc = 1;
145
146 if (!rc && (toys.optflags & FLAG_w)) {
147 char c = 0;
148
149 if ((start+matches.rm_so)!=line) {
150 c = start[matches.rm_so-1];
151 if (!isalnum(c) && c != '_') c = 0;
152 }
153 if (!c) {
154 c = start[matches.rm_eo];
155 if (!isalnum(c) && c != '_') c = 0;
156 }
157 if (c) {
158 start += matches.rm_so+1;
159
160 continue;
161 }
162 }
163
164 if (toys.optflags & FLAG_v) {
165 if (toys.optflags & FLAG_o) {
166 if (rc) skip = matches.rm_eo = strlen(start);
167 else if (!matches.rm_so) {
168 start += skip;
169 continue;
170 } else matches.rm_eo = matches.rm_so;
171 } else {
172 if (!rc) break;
173 matches.rm_eo = strlen(start);
174 }
175 matches.rm_so = 0;
176 } else if (rc) break;
177
178 // At least one line we didn't print since match while -ABC active
179 if (bars) {
180 xputs(bars);
181 bars = 0;
182 }
183 mmatch++;
184 toys.exitval = 0;
185 if (toys.optflags & FLAG_q) xexit();
186 if (toys.optflags & FLAG_l) {
187 xprintf("%s%c", name, TT.outdelim);
188 free(line);
189 fclose(file);
190 return;
191 }
192 if (toys.optflags & FLAG_o)
193 if (matches.rm_eo == matches.rm_so)
194 break;
195
196 if (!(toys.optflags & FLAG_c)) {
197 long bcount = 1 + offset + (start-line) +
198 ((toys.optflags & FLAG_o) ? matches.rm_so : 0);
199
200 if (!(toys.optflags & FLAG_o)) {
201 while (dlb) {
202 struct double_list *dl = dlist_pop(&dlb);
203
204 outline(dl->data, '-', name, lcount-before, 0, 0);
205 free(dl->data);
206 free(dl);
207 before--;
208 }
209
210 outline(line, ':', name, lcount, bcount, 0);
211 if (TT.a) after = TT.a+1;
212 } else outline(start+matches.rm_so, ':', name, lcount, bcount,
213 matches.rm_eo-matches.rm_so);
214 }
215
216 start += skip;
217 if (!(toys.optflags & FLAG_o)) break;
218 } while (*start);
219 offset += len;
220
221 if (mmatch) mcount++;
222 else {
223 int discard = (after || TT.b);
224
225 if (after && --after) {
226 outline(line, '-', name, lcount, 0, 0);
227 discard = 0;
228 }
229 if (discard && TT.b) {
230 dlist_add(&dlb, line);
231 line = 0;
232 if (++before>TT.b) {
233 struct double_list *dl;
234
235 dl = dlist_pop(&dlb);
236 free(dl->data);
237 free(dl);
238 before--;
239 } else discard = 0;
240 }
241 // If we discarded a line while displaying context, show bars before next
242 // line (but don't show them now in case that was last match in file)
243 if (discard && mcount) bars = "--";
244 }
245 free(line);
246
247 if ((toys.optflags & FLAG_m) && mcount >= TT.m) break;
248 }
249
250 if (toys.optflags & FLAG_c) outline(0, ':', name, mcount, 0, 0);
251
252 // loopfiles will also close the fd, but this frees an (opaque) struct.
253 fclose(file);
254 }
255
parse_regex(void)256 static void parse_regex(void)
257 {
258 struct arg_list *al, *new, *list = NULL;
259 long len = 0;
260 char *s, *ss;
261
262 // Add all -f lines to -e list. (Yes, this is leaking allocation context for
263 // exit to free. Not supporting nofork for this command any time soon.)
264 al = TT.f ? TT.f : TT.e;
265 while (al) {
266 if (TT.f) s = ss = xreadfile(al->arg, 0, 0);
267 else s = ss = al->arg;
268
269 // Split lines at \n, add individual lines to new list.
270 do {
271 ss = strchr(s, '\n');
272 if (ss) *(ss++) = 0;
273 new = xmalloc(sizeof(struct arg_list));
274 new->next = list;
275 new->arg = s;
276 list = new;
277 s = ss;
278 } while (ss && *s);
279
280 // Advance, when we run out of -f switch to -e.
281 al = al->next;
282 if (!al && TT.f) {
283 TT.f = 0;
284 al = TT.e;
285 }
286 }
287 TT.e = list;
288
289 if (!(toys.optflags & FLAG_F)) {
290 char *regstr;
291 int i;
292
293 // Convert strings to one big regex
294 for (al = TT.e; al; al = al->next)
295 len += strlen(al->arg)+1+!(toys.optflags & FLAG_E);
296
297 regstr = s = xmalloc(len);
298 for (al = TT.e; al; al = al->next) {
299 s = stpcpy(s, al->arg);
300 if (!(toys.optflags & FLAG_E)) *(s++) = '\\';
301 *(s++) = '|';
302 }
303 *(s-=(1+!(toys.optflags & FLAG_E))) = 0;
304
305 i = regcomp((regex_t *)toybuf, regstr,
306 ((toys.optflags & FLAG_E) ? REG_EXTENDED : 0) |
307 ((toys.optflags & FLAG_i) ? REG_ICASE : 0));
308
309 if (i) {
310 regerror(i, (regex_t *)toybuf, toybuf+sizeof(regex_t),
311 sizeof(toybuf)-sizeof(regex_t));
312 error_exit("bad REGEX: %s", toybuf);
313 }
314 }
315 }
316
do_grep_r(struct dirtree * new)317 static int do_grep_r(struct dirtree *new)
318 {
319 char *name;
320
321 if (new->parent && !dirtree_notdotdot(new)) return 0;
322 if (S_ISDIR(new->st.st_mode)) return DIRTREE_RECURSE;
323
324 // "grep -r onefile" doesn't show filenames, but "grep -r onedir" should.
325 if (new->parent && !(toys.optflags & FLAG_h)) toys.optflags |= FLAG_H;
326
327 name = dirtree_path(new, 0);
328 do_grep(openat(dirtree_parentfd(new), new->name, 0), name);
329 free(name);
330
331 return 0;
332 }
333
grep_main(void)334 void grep_main(void)
335 {
336 char **ss = toys.optargs;
337
338 if (!TT.a) TT.a = TT.c;
339 if (!TT.b) TT.b = TT.c;
340
341 TT.indelim = '\n' * !(toys.optflags&FLAG_z);
342 TT.outdelim = '\n' * !(toys.optflags&FLAG_Z);
343
344 // Handle egrep and fgrep
345 if (*toys.which->name == 'e') toys.optflags |= FLAG_E;
346 if (*toys.which->name == 'f') toys.optflags |= FLAG_F;
347
348 if (!TT.e && !TT.f) {
349 if (!*ss) error_exit("no REGEX");
350 TT.e = xzalloc(sizeof(struct arg_list));
351 TT.e->arg = *(ss++);
352 toys.optc--;
353 }
354
355 parse_regex();
356
357 if (!(toys.optflags & FLAG_h) && toys.optc>1) toys.optflags |= FLAG_H;
358
359 toys.exitval = 1;
360 if (toys.optflags & FLAG_s) {
361 close(2);
362 xopen("/dev/null", O_RDWR);
363 }
364
365 if (toys.optflags & FLAG_r) {
366 // Iterate through -r arguments. Use "." as default if none provided.
367 for (ss = *ss ? ss : (char *[]){".", 0}; *ss; ss++) {
368 if (!strcmp(*ss, "-")) do_grep(0, *ss);
369 else dirtree_read(*ss, do_grep_r);
370 }
371 } else loopfiles_rw(ss, O_RDONLY, 0, 1, do_grep);
372 }
373