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authorGravatar Mark Whitley <markw@lineo.com>2001-02-09 00:41:10 +0000
committerGravatar Mark Whitley <markw@lineo.com>2001-02-09 00:41:10 +0000
commit2fd52989f734c0e85e4a4733351cf3ce4b8c47c7 (patch)
treee91560b567b11c09e4c49ee9dc1ae2acc8681972 /findutils
parentd238a7bcc8412bb1ccc008d1e005007ed500e35b (diff)
downloadbusybox-2fd52989f734c0e85e4a4733351cf3ce4b8c47c7.tar.gz
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Implemented -A, -B, and -C flags with BB_FEATURE_GREP_CONTEXT option set.
Diffstat (limited to 'findutils')
-rw-r--r--findutils/grep.c139
1 files changed, 125 insertions, 14 deletions
diff --git a/findutils/grep.c b/findutils/grep.c
index ce2990f64..3eea7792f 100644
--- a/findutils/grep.c
+++ b/findutils/grep.c
@@ -28,10 +28,10 @@
#include <errno.h>
#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(&regex, 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(&regex, 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. */