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authorGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-02-23 11:54:37 +0000
committerGravatar Denis Vlasenko <vda.linux@googlemail.com>2008-02-23 11:54:37 +0000
commitd2172c04e6c53aedc9194d0a86a4686e5af31364 (patch)
treedb4e6a4a20d19005b30c96a9e504bb330e544cc1 /miscutils/less.c
parent33196372bed41405ff240f13fe63ca5587912ed2 (diff)
downloadbusybox-d2172c04e6c53aedc9194d0a86a4686e5af31364.tar.gz
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less: make it a bit more resistant against statusline corruption.
less: "examine" command will not bomb out on bad file name now less_main 1663 1694 +31 examine_file 87 114 +27 less_getch 138 160 +22 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 3/0 up/down: 80/0) Total: 80 bytes text data bss dec hex filename 798368 740 7484 806592 c4ec0 busybox_old 798470 740 7484 806694 c4f26 busybox_unstripped
Diffstat (limited to 'miscutils/less.c')
-rw-r--r--miscutils/less.c31
1 files changed, 20 insertions, 11 deletions
diff --git a/miscutils/less.c b/miscutils/less.c
index 4229dfe15..246cc6e9b 100644
--- a/miscutils/less.c
+++ b/miscutils/less.c
@@ -706,13 +706,16 @@ static ssize_t getch_nowait(char* input, int sz)
/* Grab a character from input without requiring the return key. If the
* character is ASCII \033, get more characters and assign certain sequences
* special return codes. Note that this function works best with raw input. */
-static int less_getch(void)
+static int less_getch(int pos)
{
unsigned char input[16];
unsigned i;
+
again:
+ less_gets_pos = pos;
memset(input, 0, sizeof(input));
getch_nowait(input, sizeof(input));
+ less_gets_pos = -1;
/* Detect escape sequences (i.e. arrow keys) and handle
* them accordingly */
@@ -777,12 +780,17 @@ static void examine_file(void)
char *new_fname;
print_statusline("Examine: ");
- new_fname = less_gets(sizeof("Examine: ")-1);
+ new_fname = less_gets(sizeof("Examine: ") - 1);
if (!new_fname[0]) {
- free(new_fname);
status_print();
+ err:
+ free(new_fname);
return;
}
+ if (access(new_fname, R_OK) != 0) {
+ print_statusline("Cannot read this file");
+ goto err;
+ }
free(filename);
filename = new_fname;
/* files start by = argv. why we assume that argv is infinitely long??
@@ -838,7 +846,7 @@ static void colon_process(void)
/* Clear the current line and print a prompt */
print_statusline(" :");
- keypress = less_getch();
+ keypress = less_getch(2);
switch (keypress) {
case 'd':
remove_current_file();
@@ -971,7 +979,7 @@ static void regex_process(void)
static void number_process(int first_digit)
{
- int i = 1;
+ int i;
int num;
char num_input[sizeof(int)*4]; /* more than enough */
char keypress;
@@ -983,8 +991,9 @@ static void number_process(int first_digit)
printf(":%c", first_digit);
/* Receive input until a letter is given */
+ i = 1;
while (i < sizeof(num_input)-1) {
- num_input[i] = less_getch();
+ num_input[i] = less_getch(i + 1);
if (!num_input[i] || !isdigit(num_input[i]))
break;
bb_putchar(num_input[i]);
@@ -1043,7 +1052,7 @@ static void flag_change(void)
clear_line();
bb_putchar('-');
- keypress = less_getch();
+ keypress = less_getch(1);
switch (keypress) {
case 'M':
@@ -1068,7 +1077,7 @@ static void show_flag_status(void)
clear_line();
bb_putchar('_');
- keypress = less_getch();
+ keypress = less_getch(1);
switch (keypress) {
case 'M':
@@ -1127,7 +1136,7 @@ static void add_mark(void)
int letter;
print_statusline("Mark: ");
- letter = less_getch();
+ letter = less_getch(sizeof("Mark: ") - 1);
if (isalpha(letter)) {
/* If we exceed 15 marks, start overwriting previous ones */
@@ -1148,7 +1157,7 @@ static void goto_mark(void)
int i;
print_statusline("Go to mark: ");
- letter = less_getch();
+ letter = less_getch(sizeof("Go to mark: ") - 1);
clear_line();
if (isalpha(letter)) {
@@ -1385,7 +1394,7 @@ int less_main(int argc, char **argv)
reinitialize();
while (1) {
- keypress = less_getch();
+ keypress = less_getch(-1); /* -1: do not position cursor */
keypress_process(keypress);
}
}