Mercurial > hg > toybox
view toys/posix/grep.c @ 1531:3ff823086c99 draft
Teach ln -f to leave original target alone if link creation fails.
Suggested by Ashwini Sharma, I wound up implementing it by creating the new
link at a temporary name and renaming it over the old one instead of renaming
the old file out of the way and putting it back if it failed.
(Because "mkdir -p one/one/blah && ln -sf /bin/one one" would otherwise
rename one/one out of the way and only notice it can't delete it way at the
end when recovery's darn awkward, vs create new thing and if rename fails
(including EISDIR) that's the main error path. And yes the temporary name
is in the same directory as the destination so we never rename between mounts.)
link over the old one instead of renaming the old file and renaming it back.
author | Rob Landley <rob@landley.net> |
---|---|
date | Wed, 22 Oct 2014 17:11:06 -0500 |
parents | 9e105bab92e5 |
children | 5fac2769a159 |
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/* 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, "ZzEFHabhinorsvwclqe*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 -z input NUL terminated 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) -Z output NUL terminated output prefix (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; char indelim = '\n' * !(toys.optflags&FLAG_z), outdelim = '\n' * !(toys.optflags&FLAG_Z); 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 = getdelim(&line, &unused, indelim, file))) break; if (line[len-1] == indelim) 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 (toys.optflags & FLAG_x) { int i = (toys.optflags & FLAG_i); if ((i ? strcasecmp : strcmp)(seek->arg, line)) s = line; } else 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++; toys.exitval = 0; if (toys.optflags & FLAG_q) xexit(); if (toys.optflags & FLAG_l) { printf("%s%c", name, outdelim); 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)) xprintf("%s%c", line, outdelim); else { xprintf("%.*s%c", matches[which].rm_eo - matches[which].rm_so, start + matches[which].rm_so, outdelim); } } 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%c", mcount, outdelim); } // 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, 0, 0); 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+!(toys.optflags & FLAG_E); 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); }