From 2fd52989f734c0e85e4a4733351cf3ce4b8c47c7 Mon Sep 17 00:00:00 2001 From: Mark Whitley Date: Fri, 9 Feb 2001 00:41:10 +0000 Subject: Implemented -A, -B, and -C flags with BB_FEATURE_GREP_CONTEXT option set. --- grep.c | 139 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 125 insertions(+), 14 deletions(-) (limited to 'grep.c') diff --git a/grep.c b/grep.c index ce2990f64..3eea7792f 100644 --- a/grep.c +++ b/grep.c @@ -28,10 +28,10 @@ #include #include "busybox.h" -extern void xregcomp(regex_t *preg, const char *regex, int cflags); extern int optind; /* in unistd.h */ extern int errno; /* for use with strerror() */ +extern void xregcomp(regex_t *preg, const char *regex, int cflags); /* in busybox.h */ /* options */ static int ignore_case = 0; @@ -42,11 +42,34 @@ static int be_quiet = 0; static int invert_search = 0; static int suppress_err_msgs = 0; -/* globals */ +#ifdef BB_FEATURE_GREP_CONTEXT +extern char *optarg; /* in getopt.h */ +static int lines_before = 0; +static int lines_after = 0; +static char **before_buf = NULL; +static int last_line_printed = 0; +#endif /* BB_FEATURE_GREP_CONTEXT */ + +/* globals used internally */ static regex_t regex; /* storage space for compiled regular expression */ static int matched; /* keeps track of whether we ever matched */ static char *cur_file = NULL; /* the current file we are reading */ +static void print_line(const char *line, int linenum, char decoration) +{ +#ifdef BB_FEATURE_GREP_CONTEXT + /* possibly print the little '--' seperator */ + if (last_line_printed && last_line_printed < linenum - 1) { + puts("--"); + } + last_line_printed = linenum; +#endif + if (print_filename) + printf("%s%c", cur_file, decoration); + if (print_line_num) + printf("%i%c", linenum, decoration); + puts(line); +} static void grep_file(FILE *file) { @@ -54,15 +77,23 @@ static void grep_file(FILE *file) int ret; int linenum = 0; int nmatches = 0; +#ifdef BB_FEATURE_GREP_CONTEXT + int print_n_lines_after = 0; + int curpos = 0; /* track where we are in the circular 'before' buffer */ + int idx = 0; /* used for iteration through the circular buffer */ +#endif /* BB_FEATURE_GREP_CONTEXT */ while ((line = get_line_from_file(file)) != NULL) { chomp(line); linenum++; - ret = regexec(®ex, line, 0, NULL, 0); - /* test for a postitive-assertion match (regexec returned success (0) + /* + * test for a postitive-assertion match (regexec returns success (0) * and the user did not specify invert search), or a negative-assertion - * match (vice versa) */ + * match (regexec returns failure (REG_NOMATCH) and the user specified + * invert search) + */ + ret = regexec(®ex, line, 0, NULL, 0); if ((ret == 0 && !invert_search) || (ret == REG_NOMATCH && invert_search)) { /* if we found a match but were told to be quiet, stop here and @@ -72,17 +103,62 @@ static void grep_file(FILE *file) exit(0); } - /* otherwise, keep track of matches, print the matched line, and - * whatever else the user wanted */ + /* otherwise, keep track of matches and print the matched line */ nmatches++; if (!print_count_only) { - if (print_filename) - printf("%s:", cur_file); - if (print_line_num) - printf("%i:", linenum); - puts(line); +#ifdef BB_FEATURE_GREP_CONTEXT + int prevpos = (curpos == 0) ? lines_before - 1 : curpos - 1; + + /* if we were told to print 'before' lines and there is at least + * one line in the circular buffer, print them */ + if (lines_before && before_buf[prevpos] != NULL) + { + int first_buf_entry_line_num = linenum - lines_before; + + /* advance to the first entry in the circular buffer, and + * figure out the line number is of the first line in the + * buffer */ + idx = curpos; + while (before_buf[idx] == NULL) { + idx = (idx + 1) % lines_before; + first_buf_entry_line_num++; + } + + /* now print each line in the buffer, clearing them as we go */ + while (before_buf[idx] != NULL) { + print_line(before_buf[idx], first_buf_entry_line_num, '-'); + free(before_buf[idx]); + before_buf[idx] = NULL; + idx = (idx + 1) % lines_before; + first_buf_entry_line_num++; + } + + } + + /* make a note that we need to print 'after' lines */ + print_n_lines_after = lines_after; +#endif /* BB_FEATURE_GREP_CONTEXT */ + print_line(line, linenum, ':'); + } + } +#ifdef BB_FEATURE_GREP_CONTEXT + else { /* no match */ + /* Add the line to the circular 'before' buffer */ + if(lines_before) + { + if(before_buf[curpos]) + free(before_buf[curpos]); + before_buf[curpos] = strdup(line); + curpos = (curpos + 1) % lines_before; } } + + /* if we need to print some context lines after the last match, do so */ + if (print_n_lines_after && (last_line_printed != linenum)) { + print_line(line, linenum, '-'); + print_n_lines_after--; + } +#endif /* BB_FEATURE_GREP_CONTEXT */ free(line); } @@ -93,7 +169,7 @@ static void grep_file(FILE *file) printf("%i\n", nmatches); } - /* record if we matched */ + /* remember if we matched */ if (nmatches != 0) matched = 1; } @@ -102,9 +178,16 @@ extern int grep_main(int argc, char **argv) { int opt; int reflags; +#ifdef BB_FEATURE_GREP_CONTEXT + char *junk; +#endif /* do normal option parsing */ - while ((opt = getopt(argc, argv, "iHhnqvsc")) > 0) { + while ((opt = getopt(argc, argv, "iHhnqvsc" +#ifdef BB_FEATURE_GREP_CONTEXT +"A:B:C:" +#endif +)) > 0) { switch (opt) { case 'i': ignore_case++; @@ -130,6 +213,25 @@ extern int grep_main(int argc, char **argv) case 'c': print_count_only++; break; +#ifdef BB_FEATURE_GREP_CONTEXT + case 'A': + lines_after = strtoul(optarg, &junk, 10); + if(*junk != '\0') + error_msg_and_die("invalid context length argument"); + break; + case 'B': + lines_before = strtoul(optarg, &junk, 10); + if(*junk != '\0') + error_msg_and_die("invalid context length argument"); + before_buf = (char **)calloc(lines_before, sizeof(char *)); + break; + case 'C': + lines_after = lines_before = strtoul(optarg, &junk, 10); + if(*junk != '\0') + error_msg_and_die("invalid context length argument"); + before_buf = (char **)calloc(lines_before, sizeof(char *)); + break; +#endif /* BB_FEATURE_GREP_CONTEXT */ } } @@ -137,6 +239,15 @@ extern int grep_main(int argc, char **argv) if (argv[optind] == NULL) usage(grep_usage); + /* sanity check */ + if (print_count_only || be_quiet) { + print_line_num = 0; +#ifdef BB_FEATURE_GREP_CONTEXT + lines_before = 0; + lines_after = 0; +#endif + } + /* compile the regular expression * we're not going to mess with sub-expressions, and we need to * treat newlines right. */ -- cgit v1.2.3