diff options
Diffstat (limited to 'toys/posix/grep.c')
| -rw-r--r-- | toys/posix/grep.c | 286 |
1 files changed, 286 insertions, 0 deletions
diff --git a/toys/posix/grep.c b/toys/posix/grep.c new file mode 100644 index 00000000..7a2ca3a3 --- /dev/null +++ b/toys/posix/grep.c @@ -0,0 +1,286 @@ +/* grep.c - print lines what match given regular expression + * + * Copyright 2013 CE Strake <strake888 at gmail.com> + * + * See http://pubs.opengroup.org/onlinepubs/9699919799/utilities/grep.html + +USE_GREP(NEWTOY(grep, "EFHabhinorsvwclqe*f*m#x[!wx][!EFw]", TOYFLAG_BIN)) +USE_GREP(OLDTOY(egrep, grep, OPTSTR_grep, TOYFLAG_BIN)) +USE_GREP(OLDTOY(fgrep, grep, OPTSTR_grep, TOYFLAG_BIN)) + +config GREP + bool "grep" + default y + help + usage: grep [-EFivwcloqsHbhn] [-m MAX] [-e REGEX]... [-f REGFILE] [FILE]... + + Show lines matching regular expressions. If no -e, first argument is + regular expression to match. With no files (or "-" filename) read stdin. + Returns 0 if matched, 1 if no match found. + + -e Regex to match. (May be repeated.) + -f File containing regular expressions to match. + + match type: + -E extended regex syntax -F fixed (match literal string) + -i case insensitive -m stop after this many lines matched + -r recursive (on dir) -v invert match + -w whole word (implies -E) -x whole line + + display modes: (default: matched line) + -c count of matching lines -l show matching filenames + -o only matching part -q quiet (errors only) + -s silent (no error msg) + + prefix modes (default: filename if checking more than 1 file) + -H force filename -b byte offset of match + -h hide filename -n line number of match +*/ + +#define FOR_grep +#include "toys.h" +#include <regex.h> + +GLOBALS( + long m; + struct arg_list *f; + struct arg_list *e; + + struct arg_list *regex; +) + +static void do_grep(int fd, char *name) +{ + FILE *file = fdopen(fd, "r"); + long offset = 0; + int lcount = 0, mcount = 0, which = toys.optflags & FLAG_w ? 2 : 0; + + if (!fd) name = "(standard input)"; + + if (!file) { + perror_msg("%s", name); + return; + } + + for (;;) { + char *line = 0, *start; + regmatch_t matches[3]; + size_t unused; + long len; + int mmatch = 0; + + lcount++; + if (0 > (len = getline(&line, &unused, file))) break; + if (line[len-1] == '\n') line[len-1] = 0; + + start = line; + + for (;;) + { + int rc = 0, skip = 0; + + if (toys.optflags & FLAG_F) { + struct arg_list *seek, fseek; + char *s = 0; + + for (seek = TT.e; seek; seek = seek->next) { + if (!*seek->arg) { + seek = &fseek; + fseek.arg = s = line; + break; + } + if (toys.optflags & FLAG_i) { + long ll = strlen(seek->arg);; + + // Alas, posix hasn't got strcasestr() + for (s = line; *s; s++) if (!strncasecmp(s, seek->arg, ll)) break; + if (!*s) s = 0; + } else s = strstr(line, seek->arg); + if (s) break; + } + + if (s) { + matches[which].rm_so = (s-line); + skip = matches[which].rm_eo = (s-line)+strlen(seek->arg); + } else rc = 1; + } else { + rc = regexec((regex_t *)toybuf, start, 3, matches, + start==line ? 0 : REG_NOTBOL); + skip = matches[which].rm_eo; + } + + if (toys.optflags & FLAG_x) + if (matches[which].rm_so || line[matches[which].rm_eo]) rc = 1; + + if (toys.optflags & FLAG_v) { + if (toys.optflags & FLAG_o) { + if (rc) skip = matches[which].rm_eo = strlen(start); + else if (!matches[which].rm_so) { + start += skip; + continue; + } else matches[which].rm_eo = matches[which].rm_so; + } else { + if (!rc) break; + matches[which].rm_eo = strlen(start); + } + matches[which].rm_so = 0; + } else if (rc) break; + + mmatch++; + if (toys.optflags & FLAG_q) { + toys.exitval = 0; + xexit(); + } + if (toys.optflags & FLAG_l) { + printf("%s\n", name); + free(line); + fclose(file); + return; + } + if (toys.optflags & FLAG_o) + if (matches[which].rm_eo == matches[which].rm_so) + break; + + if (!(toys.optflags & FLAG_c)) { + if (toys.optflags & FLAG_H) printf("%s:", name); + if (toys.optflags & FLAG_n) printf("%d:", lcount); + if (toys.optflags & FLAG_b) + printf("%ld:", offset + (start-line) + + ((toys.optflags & FLAG_o) ? matches[which].rm_so : 0)); + if (!(toys.optflags & FLAG_o)) xputs(line); + else { + xprintf("%.*s\n", matches[which].rm_eo - matches[which].rm_so, + start + matches[which].rm_so); + } + } + + start += skip; + if (!(toys.optflags & FLAG_o) || !*start) break; + } + offset += len; + + free(line); + + if (mmatch) mcount++; + if ((toys.optflags & FLAG_m) && mcount >= TT.m) break; + } + + if (toys.optflags & FLAG_c) { + if (toys.optflags & FLAG_H) printf("%s:", name); + xprintf("%d\n", mcount); + } + + // loopfiles will also close the fd, but this frees an (opaque) struct. + fclose(file); +} + +static void parse_regex(void) +{ + struct arg_list *al, *new, *list = NULL; + long len = 0; + char *s, *ss; + + // Add all -f lines to -e list. (Yes, this is leaking allocation context for + // exit to free. Not supporting nofork for this command any time soon.) + al = TT.f ? TT.f : TT.e; + while (al) { + if (TT.f) s = ss = xreadfile(al->arg); + else s = ss = al->arg; + + do { + ss = strchr(s, '\n'); + if (ss) *(ss++) = 0; + new = xmalloc(sizeof(struct arg_list)); + new->next = list; + new->arg = s; + list = new; + s = ss; + } while (ss && *s); + al = al->next; + if (!al && TT.f) { + TT.f = 0; + al = TT.e; + } + } + TT.e = list; + + if (!(toys.optflags & FLAG_F)) { + int w = toys.optflags & FLAG_w; + char *regstr; + + // Convert strings to one big regex + if (w) len = 36; + for (al = TT.e; al; al = al->next) len += strlen(al->arg)+1; + + regstr = s = xmalloc(len); + if (w) s = stpcpy(s, "(^|[^_[:alnum:]])("); + for (al = TT.e; al; al = al->next) { + s = stpcpy(s, al->arg); + if (!(toys.optflags & FLAG_E)) *(s++) = '\\'; + *(s++) = '|'; + } + *(s-=(1+!(toys.optflags & FLAG_E))) = 0; + if (w) strcpy(s, ")($|[^_[:alnum:]])"); + + w = regcomp((regex_t *)toybuf, regstr, + ((toys.optflags & FLAG_E) ? REG_EXTENDED : 0) | + ((toys.optflags & FLAG_i) ? REG_ICASE : 0)); + + if (w) { + regerror(w, (regex_t *)toybuf, toybuf+sizeof(regex_t), + sizeof(toybuf)-sizeof(regex_t)); + error_exit("bad REGEX: %s", toybuf); + } + } +} + +static int do_grep_r(struct dirtree *new) +{ + char *name; + + if (new->parent && !dirtree_notdotdot(new)) return 0; + if (S_ISDIR(new->st.st_mode)) return DIRTREE_RECURSE; + + // "grep -r onefile" doesn't show filenames, but "grep -r onedir" should. + if (new->parent && !(toys.optflags & FLAG_h)) toys.optflags |= FLAG_H; + + name = dirtree_path(new, 0); + do_grep(openat(dirtree_parentfd(new), new->name, 0), name); + free(name); + + return 0; +} + +void grep_main(void) +{ + char **ss; + + // Handle egrep and fgrep + if (*toys.which->name == 'e' || (toys.optflags & FLAG_w)) + toys.optflags |= FLAG_E; + if (*toys.which->name == 'f') toys.optflags |= FLAG_F; + + if (!TT.e && !TT.f) { + if (!*toys.optargs) error_exit("no REGEX"); + TT.e = xzalloc(sizeof(struct arg_list)); + TT.e->arg = *(toys.optargs++); + toys.optc--; + } + + parse_regex(); + + if (!(toys.optflags & FLAG_h) && toys.optc>1) toys.optflags |= FLAG_H; + + toys.exitval = 1; + if (toys.optflags & FLAG_s) { + close(2); + xopen("/dev/null", O_RDWR); + } + + if (toys.optflags & FLAG_r) { + for (ss=toys.optargs; *ss; ss++) { + if (!strcmp(*ss, "-")) do_grep(0, *ss); + else dirtree_read(*ss, do_grep_r); + } + } else loopfiles_rw(toys.optargs, O_RDONLY, 0, 1, do_grep); +} |