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Diffstat (limited to 'sys/lib/string/vsnprintf.c')
-rw-r--r--sys/lib/string/vsnprintf.c21
1 files changed, 20 insertions, 1 deletions
diff --git a/sys/lib/string/vsnprintf.c b/sys/lib/string/vsnprintf.c
index 1468a11..b8a4faa 100644
--- a/sys/lib/string/vsnprintf.c
+++ b/sys/lib/string/vsnprintf.c
@@ -64,10 +64,11 @@ snprintf(char *s, size_t size, const char *fmt, ...)
int
vsnprintf(char *s, size_t size, const char *fmt, va_list ap)
{
- size_t tmp_len, off = 0;
+ size_t tmp_len, num_len, off = 0;
ssize_t num = 0;
char c, c1, num_buf[256] = {0};
const char *tmp_str;
+ uint8_t pad_width = 0;
while (off < (size - 1)) {
while (*fmt && *fmt != '%') {
@@ -77,6 +78,18 @@ vsnprintf(char *s, size_t size, const char *fmt, va_list ap)
return off;
}
+ /*
+ * Handle a case where we have "%0N". For example:
+ * "%04d"
+ */
+ if (*fmt == '0') {
+ ++fmt;
+ while (*fmt >= '0' && *fmt <= '9') {
+ pad_width = pad_width * 10 + (*fmt - '0');
+ ++fmt;
+ }
+ }
+
c = *fmt++;
switch (c) {
case 'c':
@@ -86,6 +99,12 @@ vsnprintf(char *s, size_t size, const char *fmt, va_list ap)
case 'd':
num = va_arg(ap, int);
itoa(num, num_buf, 10);
+
+ if (pad_width > 0) {
+ num_len = strlen(num_buf);
+ for (size_t i = num_len; i < pad_width; ++i)
+ printc(s, size, &off, '0');
+ }
printstr(s, size, &off, num_buf);
break;
case 'p':