Rob Sullivan writes: rewrite the regex handling to improve stability
diff --git a/miscutils/less.c b/miscutils/less.c
index eee9608..84e4b61 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -104,10 +104,11 @@
#ifdef CONFIG_FEATURE_LESS_REGEXP
static int match_found;
-static int match_lines[100];
+static int *match_lines;
static int match_pos;
static int num_matches;
static int match_backwards;
+static regex_t old_pattern;
#endif
/* Needed termios structures */
@@ -235,14 +236,6 @@
add_linenumbers();
}
-/* Turn a percentage into a line number */
-static int reverse_percent(int percentage)
-{
- double linenum = percentage;
- linenum = ((linenum / 100) * num_flines) - 1;
- return(linenum);
-}
-
#ifdef CONFIG_FEATURE_LESS_FLAGS
/* Interestingly, writing calc_percent as a function and not a prototype saves around 32 bytes
@@ -463,12 +456,11 @@
static void buffer_line(int linenum)
{
int i;
-
past_eof = 0;
- if (linenum < 1 || linenum > num_flines) {
+ if (linenum < 0 || linenum > num_flines) {
clear_line();
- printf("%s%s%i%s", HIGHLIGHT, "Cannot seek to line number ", linenum, NORMAL);
+ printf("%s%s%i%s", HIGHLIGHT, "Cannot seek to line number ", linenum + 1, NORMAL);
}
else if (linenum < (num_flines - height - 2)) {
for (i = 0; i < (height - 1); i++) {
@@ -476,6 +468,7 @@
buffer[i] = bb_xstrdup(flines[linenum + i]);
}
line_pos = linenum;
+ buffer_print();
}
else {
for (i = 0; i < (height - 1); i++) {
@@ -488,6 +481,7 @@
line_pos = linenum;
/* Set past_eof so buffer_down and buffer_up act differently */
past_eof = 1;
+ buffer_print();
}
}
@@ -610,46 +604,44 @@
/* Get a regular expression from the user, and then go through the current
file line by line, running a processing regex function on each one. */
-static char *insert_highlights(char *line, int start, int end)
-{
- return bb_xasprintf("%.*s%s%.*s%s%s", start, line, HIGHLIGHT,
- end - start, line + start, NORMAL, line + end);
-}
-
-static char *process_regex_on_line(char *line, regex_t *pattern)
+static char *process_regex_on_line(char *line, regex_t *pattern, int action)
{
/* This function takes the regex and applies it to the line.
Each part of the line that matches has the HIGHLIGHT
and NORMAL escape sequences placed around it by
- insert_highlights, and then the line is returned. */
-
+ insert_highlights if action = 1, or has the escape sequences
+ removed if action = 0, and then the line is returned. */
int match_status;
char *line2 = (char *) xmalloc((sizeof(char) * (strlen(line) + 1)) + 64);
- char sub_line[256];
- int prev_eo = 0;
+ char *growline = "";
regmatch_t match_structs;
- strcpy(line2, line);
+ line2 = bb_xstrdup(line);
match_found = 0;
match_status = regexec(pattern, line2, 1, &match_structs, 0);
-
+
while (match_status == 0) {
-
- memset(sub_line, 0, sizeof(sub_line));
-
if (match_found == 0)
match_found = 1;
-
- line2 = insert_highlights(line2, match_structs.rm_so + prev_eo, match_structs.rm_eo + prev_eo);
- if ((size_t)match_structs.rm_eo + 11 + prev_eo < strlen(line2))
- strcat(sub_line, line2 + match_structs.rm_eo + 11 + prev_eo);
-
- prev_eo += match_structs.rm_eo + 11;
- match_status = regexec(pattern, sub_line, 1, &match_structs, REG_NOTBOL);
+
+ if (action) {
+ growline = bb_xasprintf("%s%.*s%s%.*s%s", growline, match_structs.rm_so, line2, HIGHLIGHT, match_structs.rm_eo - match_structs.rm_so, line2 + match_structs.rm_so, NORMAL);
+ }
+ else {
+ growline = bb_xasprintf("%s%.*s%.*s", growline, match_structs.rm_so - 4, line2, match_structs.rm_eo - match_structs.rm_so, line2 + match_structs.rm_so);
+ }
+
+ line2 += match_structs.rm_eo;
+ match_status = regexec(pattern, line2, 1, &match_structs, REG_NOTBOL);
}
-
- return line2;
+
+ growline = bb_xasprintf("%s%s", growline, line2);
+
+ return (match_found ? growline : line);
+
+ free(growline);
+ free(line2);
}
static void goto_match(int match)
@@ -665,11 +657,10 @@
static void regex_process(void)
{
char uncomp_regex[100];
- char current_line[256];
+ char *current_line;
int i;
int j = 0;
regex_t pattern;
-
/* Get the uncompiled regular expression from the user */
clear_line();
putchar((match_backwards) ? '?' : '/');
@@ -677,32 +668,43 @@
fgets(uncomp_regex, sizeof(uncomp_regex), inp);
if (strlen(uncomp_regex) == 1) {
- goto_match(match_backwards ? match_pos - 1 : match_pos + 1);
- buffer_print();
+ if (num_matches)
+ goto_match(match_backwards ? match_pos - 1 : match_pos + 1);
+ else
+ buffer_print();
return;
}
-
uncomp_regex[strlen(uncomp_regex) - 1] = '\0';
/* Compile the regex and check for errors */
xregcomp(&pattern, uncomp_regex, 0);
+ if (num_matches) {
+ /* Get rid of all the highlights we added previously */
+ for (i = 0; i <= num_flines; i++) {
+ current_line = process_regex_on_line(flines[i], &old_pattern, 0);
+ flines[i] = bb_xstrdup(current_line);
+ }
+ }
+ old_pattern = pattern;
+
/* Reset variables */
+ match_lines = xrealloc(match_lines, sizeof(int));
match_lines[0] = -1;
match_pos = 0;
num_matches = 0;
match_found = 0;
-
/* Run the regex on each line of the current file here */
for (i = 0; i <= num_flines; i++) {
- strcpy(current_line, process_regex_on_line(flines[i], &pattern));
+ current_line = process_regex_on_line(flines[i], &pattern, 1);
flines[i] = bb_xstrdup(current_line);
if (match_found) {
+ match_lines = xrealloc(match_lines, (j + 1) * sizeof(int));
match_lines[j] = i;
j++;
}
}
-
+
num_matches = j;
if ((match_lines[0] != -1) && (num_flines > height - 2)) {
if (match_backwards) {
@@ -764,7 +766,7 @@
buffer_line(num - 1);
break;
case 'p': case '%':
- buffer_line(reverse_percent(num));
+ buffer_line(((num / 100) * num_flines) - 1);
break;
#ifdef CONFIG_FEATURE_LESS_REGEXP
case 'n':
@@ -852,7 +854,6 @@
data_readlines();
buffer_init();
buffer_line(temp_line_pos);
- buffer_print();
}
@@ -866,7 +867,7 @@
printf("Log file: ");
fgets(current_line, 256, inp);
current_line[strlen(current_line) - 1] = '\0';
- if (strlen(current_line)) {
+ if (strlen(current_line) > 1) {
fp = bb_xfopen(current_line, "w");
for (i = 0; i < num_flines; i++)
fprintf(fp, "%s", flines[i]);
@@ -973,7 +974,6 @@
printf("%s%s%s", HIGHLIGHT, "No matching bracket found", NORMAL);
buffer_line(bracket_line - height + 2);
- buffer_print();
}
}
@@ -1001,7 +1001,6 @@
printf("%s%s%s", HIGHLIGHT, "No matching bracket found", NORMAL);
buffer_line(bracket_line);
- buffer_print();
}
}
@@ -1035,12 +1034,10 @@
buffer_print();
break;
case 'g': case 'p': case '<': case '%':
- buffer_up(num_flines + 1);
- buffer_print();
+ buffer_line(0);
break;
case 'G': case '>':
- buffer_down(num_flines + 1);
- buffer_print();
+ buffer_line(num_flines - height + 2);
break;
case 'q': case 'Q':
tless_exit(0);
@@ -1078,20 +1075,16 @@
case '/':
match_backwards = 0;
regex_process();
- buffer_print();
break;
case 'n':
goto_match(match_pos + 1);
- buffer_print();
break;
case 'N':
goto_match(match_pos - 1);
- buffer_print();
break;
case '?':
match_backwards = 1;
regex_process();
- buffer_print();
break;
#endif
#ifdef CONFIG_FEATURE_LESS_FLAGCS