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, 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 = xfdopen(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 // Loop through lines of input
91 for (;;) {
92 char *line = 0, *start;
93 regmatch_t matches;
94 size_t unused;
95 long len;
96 int mmatch = 0;
97
98 lcount++;
99 if (0 > (len = getdelim(&line, &unused, TT.indelim, file))) break;
100 if (line[len-1] == TT.indelim) line[len-1] = 0;
101
102 start = line;
103
104 // Loop through matches in this line
105 do {
106 int rc = 0, skip = 0;
107
108 // Handle non-regex matches
109 if (toys.optflags & FLAG_F) {
110 struct arg_list *seek, fseek;
111 char *s = 0;
112
113 for (seek = TT.e; seek; seek = seek->next) {
114 if (toys.optflags & FLAG_x) {
115 int i = (toys.optflags & FLAG_i);
116
117 if ((i ? strcasecmp : strcmp)(seek->arg, line)) s = line;
118 } else if (!*seek->arg) {
119 seek = &fseek;
120 fseek.arg = s = line;
121 break;
122 }
123 if (toys.optflags & FLAG_i) s = strnstr(line, seek->arg);
124 else s = strstr(line, seek->arg);
125 if (s) break;
126 }
127
128 if (s) {
129 matches.rm_so = (s-line);
130 skip = matches.rm_eo = (s-line)+strlen(seek->arg);
131 } else rc = 1;
132 } else {
133 rc = regexec((regex_t *)toybuf, start, 1, &matches,
134 start==line ? 0 : REG_NOTBOL);
135 skip = matches.rm_eo;
136 }
137
138 if (toys.optflags & FLAG_x)
139 if (matches.rm_so || line[matches.rm_eo]) rc = 1;
140
141 if (!rc && (toys.optflags & FLAG_w)) {
142 char c = 0;
143
144 if ((start+matches.rm_so)!=line) {
145 c = start[matches.rm_so-1];
146 if (!isalnum(c) && c != '_') c = 0;
147 }
148 if (!c) {
149 c = start[matches.rm_eo];
150 if (!isalnum(c) && c != '_') c = 0;
151 }
152 if (c) {
153 start += matches.rm_so+1;
154
155 continue;
156 }
157 }
158
159 if (toys.optflags & FLAG_v) {
160 if (toys.optflags & FLAG_o) {
161 if (rc) skip = matches.rm_eo = strlen(start);
162 else if (!matches.rm_so) {
163 start += skip;
164 continue;
165 } else matches.rm_eo = matches.rm_so;
166 } else {
167 if (!rc) break;
168 matches.rm_eo = strlen(start);
169 }
170 matches.rm_so = 0;
171 } else if (rc) break;
172
173 // At least one line we didn't print since match while -ABC active
174 if (bars) {
175 xputs(bars);
176 bars = 0;
177 }
178 mmatch++;
179 toys.exitval = 0;
180 if (toys.optflags & FLAG_q) xexit();
181 if (toys.optflags & FLAG_l) {
182 xprintf("%s%c", name, TT.outdelim);
183 free(line);
184 fclose(file);
185 return;
186 }
187 if (toys.optflags & FLAG_o)
188 if (matches.rm_eo == matches.rm_so)
189 break;
190
191 if (!(toys.optflags & FLAG_c)) {
192 long bcount = 1 + offset + (start-line) +
193 ((toys.optflags & FLAG_o) ? matches.rm_so : 0);
194
195 if (!(toys.optflags & FLAG_o)) {
196 while (dlb) {
197 struct double_list *dl = dlist_pop(&dlb);
198
199 outline(dl->data, '-', name, lcount-before, 0, -1);
200 free(dl->data);
201 free(dl);
202 before--;
203 }
204
205 outline(line, ':', name, lcount, bcount, -1);
206 if (TT.a) after = TT.a+1;
207 } else outline(start+matches.rm_so, ':', name, lcount, bcount,
208 matches.rm_eo-matches.rm_so);
209 }
210
211 start += skip;
212 if (!(toys.optflags & FLAG_o)) break;
213 } while (*start);
214 offset += len;
215
216 if (mmatch) mcount++;
217 else {
218 int discard = (after || TT.b);
219
220 if (after && --after) {
221 outline(line, '-', name, lcount, 0, -1);
222 discard = 0;
223 }
224 if (discard && TT.b) {
225 dlist_add(&dlb, line);
226 line = 0;
227 if (++before>TT.b) {
228 struct double_list *dl;
229
230 dl = dlist_pop(&dlb);
231 free(dl->data);
232 free(dl);
233 before--;
234 } else discard = 0;
235 }
236 // If we discarded a line while displaying context, show bars before next
237 // line (but don't show them now in case that was last match in file)
238 if (discard && mcount) bars = "--";
239 }
240 free(line);
241
242 if ((toys.optflags & FLAG_m) && mcount >= TT.m) break;
243 }
244
245 if (toys.optflags & FLAG_c) outline(0, ':', name, mcount, 0, -1);
246
247 // loopfiles will also close the fd, but this frees an (opaque) struct.
248 fclose(file);
249 }
250
parse_regex(void)251 static void parse_regex(void)
252 {
253 struct arg_list *al, *new, *list = NULL;
254 long len = 0;
255 char *s, *ss;
256
257 // Add all -f lines to -e list. (Yes, this is leaking allocation context for
258 // exit to free. Not supporting nofork for this command any time soon.)
259 al = TT.f ? TT.f : TT.e;
260 while (al) {
261 if (TT.f) s = ss = xreadfile(al->arg, 0, 0);
262 else s = ss = al->arg;
263
264 // Split lines at \n, add individual lines to new list.
265 do {
266 ss = strchr(s, '\n');
267 if (ss) *(ss++) = 0;
268 new = xmalloc(sizeof(struct arg_list));
269 new->next = list;
270 new->arg = s;
271 list = new;
272 s = ss;
273 } while (ss && *s);
274
275 // Advance, when we run out of -f switch to -e.
276 al = al->next;
277 if (!al && TT.f) {
278 TT.f = 0;
279 al = TT.e;
280 }
281 }
282 TT.e = list;
283
284 if (!(toys.optflags & FLAG_F)) {
285 char *regstr;
286 int i;
287
288 // Convert strings to one big regex
289 for (al = TT.e; al; al = al->next)
290 len += strlen(al->arg)+1+!(toys.optflags & FLAG_E);
291
292 regstr = s = xmalloc(len);
293 for (al = TT.e; al; al = al->next) {
294 s = stpcpy(s, al->arg);
295 if (!(toys.optflags & FLAG_E)) *(s++) = '\\';
296 *(s++) = '|';
297 }
298 *(s-=(1+!(toys.optflags & FLAG_E))) = 0;
299
300 i = regcomp((regex_t *)toybuf, regstr,
301 ((toys.optflags & FLAG_E) ? REG_EXTENDED : 0) |
302 ((toys.optflags & FLAG_i) ? REG_ICASE : 0));
303
304 if (i) {
305 regerror(i, (regex_t *)toybuf, toybuf+sizeof(regex_t),
306 sizeof(toybuf)-sizeof(regex_t));
307 error_exit("bad REGEX: %s", toybuf);
308 }
309 }
310 }
311
do_grep_r(struct dirtree * new)312 static int do_grep_r(struct dirtree *new)
313 {
314 char *name;
315
316 if (!dirtree_notdotdot(new)) return 0;
317 if (S_ISDIR(new->st.st_mode)) return DIRTREE_RECURSE;
318
319 // "grep -r onefile" doesn't show filenames, but "grep -r onedir" should.
320 if (new->parent && !(toys.optflags & FLAG_h)) toys.optflags |= FLAG_H;
321
322 name = dirtree_path(new, 0);
323 do_grep(openat(dirtree_parentfd(new), new->name, 0), name);
324 free(name);
325
326 return 0;
327 }
328
grep_main(void)329 void grep_main(void)
330 {
331 char **ss = toys.optargs;
332
333 if (!TT.a) TT.a = TT.c;
334 if (!TT.b) TT.b = TT.c;
335
336 TT.indelim = '\n' * !(toys.optflags&FLAG_z);
337 TT.outdelim = '\n' * !(toys.optflags&FLAG_Z);
338
339 // Handle egrep and fgrep
340 if (*toys.which->name == 'e') toys.optflags |= FLAG_E;
341 if (*toys.which->name == 'f') toys.optflags |= FLAG_F;
342
343 if (!TT.e && !TT.f) {
344 if (!*ss) error_exit("no REGEX");
345 TT.e = xzalloc(sizeof(struct arg_list));
346 TT.e->arg = *(ss++);
347 toys.optc--;
348 }
349
350 parse_regex();
351
352 if (!(toys.optflags & FLAG_h) && toys.optc>1) toys.optflags |= FLAG_H;
353
354 toys.exitval = 1;
355 if (toys.optflags & FLAG_s) {
356 close(2);
357 xopen_stdio("/dev/null", O_RDWR);
358 }
359
360 if (toys.optflags & FLAG_r) {
361 // Iterate through -r arguments. Use "." as default if none provided.
362 for (ss = *ss ? ss : (char *[]){".", 0}; *ss; ss++) {
363 if (!strcmp(*ss, "-")) do_grep(0, *ss);
364 else dirtree_read(*ss, do_grep_r);
365 }
366 } else loopfiles_rw(ss, O_RDONLY|WARN_ONLY, 0, do_grep);
367 }
368