xref: /aosp_15_r20/external/toybox/toys/posix/grep.c (revision cf5a6c84e2b8763fc1a7db14496fd4742913b199)
1 /* grep.c - show lines matching regular expressions
2  *
3  * Copyright 2013 CE Strake <strake888 at gmail.com>
4  *
5  * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html
6  *
7  * Posix doesn't even specify -r: too many deviations to document.
8  * TODO: -i is only ascii case insensitive, not unicode.
9 
10 USE_GREP(NEWTOY(grep, "(line-buffered)(color):;(exclude-dir)*S(exclude)*M(include)*ZzEFHIab(byte-offset)h(no-filename)ino(only-matching)rRsvwc(count)L(files-without-match)l(files-with-matches)q(quiet)(silent)e*f*C#B#A#m#x[!wx][!EF]", TOYFLAG_BIN|TOYFLAG_ARGFAIL(2)|TOYFLAG_LINEBUF|TOYFLAG_AUTOCONF))
11 USE_EGREP(OLDTOY(egrep, grep, TOYFLAG_BIN|TOYFLAG_ARGFAIL(2)|TOYFLAG_LINEBUF|TOYFLAG_AUTOCONF))
12 USE_FGREP(OLDTOY(fgrep, grep, TOYFLAG_BIN|TOYFLAG_ARGFAIL(2)|TOYFLAG_LINEBUF|TOYFLAG_AUTOCONF))
13 
14 config GREP
15   bool "grep"
16   default y
17   help
18     usage: grep [-abcEFHhIiLlnoqrsvwxZz] [-ABC NUM] [-m MAX] [-e REGEX]... [-MS PATTERN]... [-f REGFILE]... [FILE]...
19 
20     Show lines matching regular expressions. If no -e, first argument is
21     regular expression to match. With no files (or "-" filename) read stdin.
22     Returns 0 if matched, 1 if no match found, 2 for command errors.
23 
24     -e  Regex(es) to match.       -f  File(s) of regexes to match (1 per line).
25 
26     file search:
27     -r  Recurse into subdirs     -R  Recurse following symlinks
28     -M  Match files (--include)  -S  Skip files (--exclude)
29     -I  Ignore binary files      --exclude-dir=PATTERN  Skip directories
30 
31     match type:
32     -A  Show NUM lines after     -B  Show NUM lines before match
33     -C  NUM lines context (A+B)  -E  extended regex syntax
34     -F  fixed (literal match)    -a  always text (not binary)
35     -i  case insensitive         -m  match MAX many lines
36     -v  invert match             -w  whole word (implies -E)
37     -x  whole line               -z  input NUL terminated
38 
39     display modes: (default: matched line)
40     -L  filenames with no match  -Z  output is NUL terminated
41     -c  count of matching lines  -l  filenames with a match
42     -o  only matching part       -q  quiet (errors only)
43     -s  silent (no error msg)
44 
45     output prefix (default: filename if checking more than 1 file)
46     -H  force filename           -b  byte offset of match
47     -h  hide filename            -n  line number of match
48 
49 config EGREP
50   bool
51   default y
52   depends on GREP
53 
54 config FGREP
55   bool
56   default y
57   depends on GREP
58 */
59 
60 #define FOR_grep
61 #include "toys.h"
62 
63 GLOBALS(
64   long m, A, B, C;
65   struct arg_list *f, *e, *M, *S, *exclude_dir;
66   char *color;
67 
68   char *purple, *cyan, *red, *green, *grey;
69   struct double_list *reg;
70   int found, tried, delim;
71   struct arg_list **fixed;
72 )
73 
74 struct reg {
75   struct reg *next, *prev;
76   int rc;
77   regex_t r;
78   regmatch_t m;
79 };
80 
numdash(long num,char dash)81 static void numdash(long num, char dash)
82 {
83   printf("%s%ld%s%c", TT.green, num, TT.cyan, dash);
84 }
85 
86 // Emit line with various potential prefixes and delimiter
outline(char * line,char dash,char * name,long lcount,long bcount,unsigned trim)87 static void outline(char *line, char dash, char *name, long lcount, long bcount,
88   unsigned trim)
89 {
90   if (!trim && FLAG(o)) return;
91   if (name && FLAG(H)) printf("%s%s%s%c", TT.purple, name, TT.cyan, dash);
92   if (FLAG(c)) xprintf("%s%ld%c", TT.grey, lcount, TT.delim);
93   else if (lcount && FLAG(n)) numdash(lcount, dash);
94   if (bcount && FLAG(b)) numdash(bcount-1, dash);
95   if (line) {
96     if (FLAG(color)) xputsn(FLAG(o) ? TT.red : TT.grey);
97     // support embedded NUL bytes in output
98     xputsl(line, trim);
99     xputc(TT.delim);
100   }
101 }
102 
matchw(char * line,char * start,long so,long eo)103 static int matchw(char *line, char *start, long so, long eo)
104 {
105   if (FLAG(w)) {
106     if (so+(start-line)) if (isalnum(start[so-1]) || start[so-1]=='_') return 0;
107     if (isalnum(start[eo]) || start[eo]=='_') return 0;
108   }
109 
110   return 1;
111 }
112 
113 // Show matches in one file
do_grep(int fd,char * name)114 static void do_grep(int fd, char *name)
115 {
116   long lcount = 0, mcount = 0, offset = 0, after = 0, before = 0, new = 1;
117   struct double_list *dlb = 0;
118   char *bars = 0;
119   FILE *file;
120   int bin = 0;
121 
122   if (!FLAG(r)) TT.tried++;
123   if (!fd) name = "(standard input)";
124 
125   // Only run binary file check on lseekable files.
126   if (!FLAG(a) && !lseek(fd, 0, SEEK_CUR)) {
127     char buf[256];
128     int len, i = 0;
129     unsigned wc;
130 
131     // If the first 256 bytes don't parse as utf8, call it binary.
132     if (0<(len = read(fd, buf, 256))) {
133       lseek(fd, -len, SEEK_CUR);
134       while (i<len) {
135         bin = utf8towc(&wc, buf+i, len-i);
136         if (bin == -2) i = len;
137         if (bin<1) break;
138         i += bin;
139       }
140       bin = i!=len;
141     }
142     if (bin && FLAG(I)) return;
143   }
144 
145   if (!(file = fdopen(fd, "r"))) return perror_msg_raw(name);
146 
147   // Loop through lines of input
148   for (;;) {
149     char *line = 0, *start, *ss, *pp;
150     struct reg *shoe;
151     size_t ulen;
152     long len;
153     int matched = 0, rc = 1, move = 0, ii;
154 
155     // get next line, check and trim delimiter
156     lcount++;
157     errno = 0;
158     ulen = len = getdelim(&line, &ulen, TT.delim, file);
159     if (len == -1 && errno) perror_msg_raw(name);
160     if (len<1) break;
161     if (line[ulen-1] == TT.delim) line[--ulen] = 0;
162 
163     // Prepare for next line
164     start = line;
165     for (shoe = (void *)TT.reg; shoe; shoe = shoe->next) shoe->rc = 0;
166 
167     // Loop to handle multiple matches in same line
168     if (new) do {
169       regmatch_t *mm = (void *)toybuf;
170       struct arg_list *seek;
171 
172       mm->rm_so = mm->rm_eo = 0;
173       rc = 1;
174 
175       // Handle "fixed" (literal) matches (if any)
176       if (TT.e) for (ss = start; ss-line<=ulen; ss++) {
177         ii = FLAG(i) ? toupper(*ss) : *ss;
178         for (seek = TT.fixed[ii]; seek; seek = seek->next) {
179           if (*(pp = seek->arg)=='^' && !FLAG(F)) {
180             if (ss!=start) continue;
181             pp++;
182           }
183           for (ii = 0; pp[ii] && ss[ii]; ii++) {
184             if (!FLAG(F)) {
185               if (pp[ii]=='.') continue;
186               if (pp[ii]=='\\' && pp[ii+1]) pp++;
187               else if (pp[ii]=='$' && !pp[ii+1]) break;
188             }
189             if (FLAG(i)) {
190               if (toupper(pp[ii])!=toupper(ss[ii])) break;
191             } else if (pp[ii]!=ss[ii]) break;
192           }
193           if (pp[ii] && (pp[ii]!='$' || pp[ii+1] || ss[ii])) continue;
194           mm->rm_eo = (mm->rm_so = ss-start)+ii;
195           if (!matchw(line, start, mm->rm_so, mm->rm_eo)) continue;
196           rc = 0;
197 
198           goto got;
199         }
200         if (FLAG(x)) break;
201       }
202 
203 got:
204       // Handle regex matches (if any)
205       for (shoe = (void *)TT.reg; shoe; shoe = shoe->next) {
206         // Do we need to re-check this regex?
207         if (!shoe->rc) {
208           shoe->m.rm_so -= move;
209           shoe->m.rm_eo -= move;
210           if (!matched || shoe->m.rm_so<0)
211             shoe->rc = regexec0(&shoe->r, start, ulen-(start-line), 1,
212                                 &shoe->m, start==line ? 0 : REG_NOTBOL);
213         }
214 
215         if (!matchw(line, start, shoe->m.rm_so, shoe->m.rm_eo)) continue;
216         // If we got a match, is it a _better_ match?
217         if (!shoe->rc && (rc || shoe->m.rm_so < mm->rm_so ||
218             (shoe->m.rm_so == mm->rm_so && shoe->m.rm_eo >= mm->rm_eo)))
219         {
220           mm = &shoe->m;
221           rc = 0;
222         }
223       }
224 
225       if (!rc && FLAG(o) && !mm->rm_eo && ulen>start-line) {
226         move = 1;
227         continue;
228       }
229 
230       if (!rc && FLAG(x) && (mm->rm_so || ulen-(start-line)!=mm->rm_eo)) rc = 1;
231 
232       if (FLAG(v)) {
233         if (FLAG(o)) {
234           if (rc) mm->rm_eo = ulen-(start-line);
235           else if (!mm->rm_so) {
236             move = mm->rm_eo;
237             continue;
238           } else mm->rm_eo = mm->rm_so;
239         } else {
240           if (!rc) break;
241           mm->rm_eo = ulen-(start-line);
242         }
243         mm->rm_so = 0;
244       } else if (rc) break;
245 
246       // At least one line we didn't print since match while -ABC active
247       if (bars) {
248         xputs(bars);
249         bars = 0;
250       }
251       matched++;
252       TT.found = 1;
253 
254       // Are we NOT showing the matching text?
255       if (FLAG(q)) {
256         toys.exitval = 0;
257         xexit();
258       }
259       if (FLAG(L) || FLAG(l)) {
260         if (FLAG(l)) xprintf("%s%c", name, '\n'*!FLAG(Z));
261         free(line);
262         fclose(file);
263         return;
264       }
265 
266       if (!FLAG(c)) {
267         long bcount = 1 + offset + (start-line) + (FLAG(o) ? mm->rm_so : 0);
268 
269         if (bin) printf("Binary file %s matches\n", name);
270         else if (FLAG(o))
271           outline(start+mm->rm_so, ':', name, lcount, bcount,
272                   mm->rm_eo-mm->rm_so);
273         else {
274           while (dlb) {
275             struct double_list *dl = dlist_pop(&dlb);
276             unsigned *uu = (void *)(dl->data+(strlen(dl->data)|3)+1);
277 
278             outline(dl->data, '-', name, lcount-before, uu[0]+1, uu[1]);
279             free(dl->data);
280             free(dl);
281             before--;
282           }
283 
284           if (matched==1)
285             outline(FLAG(color) ? 0 : line, ':', name, lcount, bcount, ulen);
286           if (FLAG(color)) {
287             xputsn(TT.grey);
288             if (mm->rm_so) xputsl(start, mm->rm_so);
289             xputsn(TT.red);
290             xputsl(start+mm->rm_so, mm->rm_eo-mm->rm_so);
291           }
292 
293           if (TT.A) after = TT.A+1;
294         }
295       }
296 
297       if (mm->rm_so == (move = mm->rm_eo)) break;
298     } while (*(start += move));
299     offset += len;
300 
301     if (matched) {
302       // Finish off pending line color fragment.
303       if (FLAG(color) && !FLAG(o)) {
304         xputsn(TT.grey);
305         if (ulen > start-line) xputsl(start, ulen-(start-line));
306         xputc(TT.delim);
307       }
308       mcount++;
309     } else {
310       int discard = (after || TT.B);
311 
312       if (after && --after) {
313         outline(line, '-', name, lcount, 0, ulen);
314         discard = 0;
315       }
316       if (discard && TT.B) {
317         unsigned *uu, ul = (ulen|3)+1;
318 
319         line = xrealloc(line, ul+8);
320         uu = (void *)(line+ul);
321         uu[0] = offset-len;
322         uu[1] = ulen;
323         dlist_add(&dlb, line);
324         line = 0;
325         if (++before>TT.B) {
326           struct double_list *dl;
327 
328           dl = dlist_pop(&dlb);
329           free(dl->data);
330           free(dl);
331           before--;
332         } else discard = 0;
333       }
334       // If we discarded a line while displaying context, show bars before next
335       // line (but don't show them now in case that was last match in file)
336       if (discard && mcount) bars = "--";
337     }
338     free(line);
339 
340     if (FLAG(m) && mcount >= TT.m) {
341       if (!after) break;
342       new = 0;
343     }
344   }
345 
346   if (FLAG(L)) xprintf("%s%c", name, TT.delim);
347   else if (FLAG(c)) outline(0, ':', name, mcount, 0, 1);
348 
349   // loopfiles will also close the fd, but this frees an (opaque) struct.
350   fclose(file);
351   llist_traverse(dlb, llist_free_double);
352 }
353 
lensort(struct arg_list ** a,struct arg_list ** b)354 static int lensort(struct arg_list **a, struct arg_list **b)
355 {
356   long la = strlen((*a)->arg), lb = strlen((*b)->arg);
357 
358   if (la<lb) return -1;
359   if (la>lb) return 1;
360 
361   return 0;
362 }
363 
parse_regex(void)364 static void parse_regex(void)
365 {
366   struct arg_list *al, *new, *list = NULL, **last;
367   char *s, *ss, *special = "\\.^$[()|*+?{";
368   int len, ii, key;
369 
370   // Add all -f lines to -e list. (Yes, this is leaking allocation context for
371   // exit to free. Not supporting nofork for this command any time soon.)
372   al = TT.f ? TT.f : TT.e;
373   while (al) {
374     if (TT.f) {
375       if (!*(s = xreadfile(al->arg, 0, 0))) {
376         free(s);
377         s = 0;
378       } else if (*(ss = s+strlen(s)-1)=='\n') *ss = 0;
379     } else s = al->arg;
380 
381     // Advance, when we run out of -f switch to -e.
382     al = al->next;
383     if (!al && TT.f) {
384       TT.f = 0;
385       al = TT.e;
386     }
387     if (!s) continue;
388 
389     // NOTE: even with -z, -f is still \n delimited. Blank line = match all
390     // Split lines at \n, add individual lines to new list.
391     do {
392       if ((ss = strchr(s, '\n'))) *(ss++) = 0;
393       new = xmalloc(sizeof(struct arg_list));
394       new->next = list;
395       new->arg = s;
396       list = new;
397       s = ss;
398     } while (s);
399   }
400   TT.e = list;
401 
402   // Convert to regex where appropriate
403   for (last = &TT.e; *last;) {
404     // Can we use the fast path?
405     s = (*last)->arg;
406     if ('.'!=*s && !FLAG(F) && strcmp(s, "^$")) for (; *s; s++) {
407       if (*s=='\\') {
408         if (!s[1] || !strchr(special, *++s)) break;
409         if (!FLAG(E) && *s=='(') break;
410       } else if (*s>127 || strchr(special+4, *s)) break;
411     }
412 
413     // Leave entry in fast path (literal-ish match) or move to slow path (regex)
414     if (!*s || FLAG(F)) last = &((*last)->next);
415     else {
416       struct reg *shoe;
417 
418       dlist_add_nomalloc(&TT.reg, (void *)(shoe = xmalloc(sizeof(struct reg))));
419       xregcomp(&shoe->r, (*last)->arg, REG_EXTENDED*FLAG(E)|REG_ICASE*FLAG(i));
420       al = *last;
421       *last = (*last)->next;
422       free(al);
423     }
424   }
425   dlist_terminate(TT.reg);
426 
427   // Sort fast path patterns into buckets by first character
428   for (al = TT.e; al; al = new) {
429     new = al->next;
430     if (FLAG(F)) key = 0;
431     else {
432       key = '^'==*al->arg;
433       if ('\\'==al->arg[key]) key++;
434       else if ('$'==al->arg[key] && !al->arg[key+1]) key++;
435     }
436     key = al->arg[key];
437     if (FLAG(i)) key = toupper(key);
438     al->next = TT.fixed[key];
439     TT.fixed[key] = al;
440   }
441 
442   // Sort each fast path pattern set by length so first hit is longest match
443   // Zero length matches aren't sorted, instead appended to every list.
444   if (TT.e) for (key = 1; key<256; key++) {
445     if (!TT.fixed[key]) {
446       TT.fixed[key] = *TT.fixed;
447       continue;
448     }
449     for (len = 0, al = TT.fixed[key]; al; al = al->next) len++;
450     last = xmalloc(len*sizeof(void *));
451     for (len = 0, al = TT.fixed[key]; al; al = al->next) last[len++] = al;
452     qsort(last, len, sizeof(void *), (void *)lensort);
453     for (ii = 0; ii<len; ii++) last[ii]->next = ii ? last[ii-1] : *TT.fixed;
454     TT.fixed[key] = last[len-1];
455     free(last);
456   }
457 }
458 
do_grep_r(struct dirtree * new)459 static int do_grep_r(struct dirtree *new)
460 {
461   struct arg_list *al;
462   char *name;
463 
464   if (!new->parent) TT.tried++;
465   if (!dirtree_notdotdot(new)) return 0;
466   if (S_ISDIR(new->st.st_mode)) {
467     for (al = TT.exclude_dir; al; al = al->next)
468       if (!fnmatch(al->arg, new->name, 0)) return 0;
469     return DIRTREE_RECURSE|DIRTREE_SYMFOLLOW*FLAG(R);
470   }
471   if (TT.S || TT.M) {
472     for (al = TT.S; al; al = al->next)
473       if (!fnmatch(al->arg, new->name, 0)) return 0;
474 
475     if (TT.M) {
476       for (al = TT.M; al; al = al->next)
477         if (!fnmatch(al->arg, new->name, 0)) break;
478 
479       if (!al) return 0;
480     }
481   }
482 
483   // "grep -r onefile" doesn't show filenames, but "grep -r onedir" should.
484   if (new->parent && !FLAG(h)) toys.optflags |= FLAG_H;
485 
486   name = dirtree_path(new, 0);
487   do_grep(openat(dirtree_parentfd(new), new->name, O_NONBLOCK|O_NOCTTY), name);
488   free(name);
489 
490   return 0;
491 }
492 
grep_main(void)493 void grep_main(void)
494 {
495   char **ss = toys.optargs;
496 
497   TT.fixed = xzalloc(256*sizeof(*TT.fixed));
498 
499   if (FLAG(color) && (!TT.color || !strcmp(TT.color, "auto")) && !isatty(1))
500     toys.optflags &= ~FLAG_color;
501 
502   if (FLAG(color)) {
503     TT.purple = "\e[35m";
504     TT.cyan = "\e[36m";
505     TT.red = "\e[1;31m";
506     TT.green = "\e[32m";
507     TT.grey = "\e[m";
508   } else TT.purple = TT.cyan = TT.red = TT.green = TT.grey = "";
509 
510   if (FLAG(R)) toys.optflags |= FLAG_r;
511 
512   // Grep exits with 2 for errors
513   toys.exitval = 2;
514 
515   if (!TT.A) TT.A = TT.C;
516   if (!TT.B) TT.B = TT.C;
517 
518   TT.delim = '\n' * !FLAG(z);
519 
520   // Handle egrep and fgrep
521   if (*toys.which->name == 'e') toys.optflags |= FLAG_E;
522   if (*toys.which->name == 'f') toys.optflags |= FLAG_F;
523 
524   if (!TT.e && !TT.f) {
525     if (!*ss) error_exit("no REGEX");
526     TT.e = xzalloc(sizeof(struct arg_list));
527     TT.e->arg = *(ss++);
528     toys.optc--;
529   }
530 
531   parse_regex();
532 
533   if (!FLAG(h) && toys.optc>1) toys.optflags |= FLAG_H;
534 
535   if (FLAG(s)) {
536     close(2);
537     xopen_stdio("/dev/null", O_RDWR);
538   }
539 
540   if (FLAG(r)) {
541     // Iterate through -r arguments. Use "." as default if none provided.
542     for (ss = *ss ? ss : (char *[]){".", 0}; *ss; ss++) {
543       if (!strcmp(*ss, "-")) do_grep(0, *ss);
544       else dirtree_read(*ss, do_grep_r);
545     }
546   } else loopfiles_rw(ss, O_RDONLY|WARN_ONLY, 0, do_grep);
547   if (TT.tried >= toys.optc || (FLAG(q)&&TT.found)) toys.exitval = !TT.found;
548 }
549