At present this has a minor bug in that it reads the byte before the start of the string, if it is empty. Also it doesn't handle a non-numeric prefix which is only one character long.
Fix these bugs with a reworked implementation. Add a test for the second case. The first one is hard to test.
Signed-off-by: Simon Glass sjg@chromium.org ---
Changes in v4: - Correct the commit tag - Reword the commit message - Update the function comment to clarify its intert / limitations
include/vsprintf.h | 3 +++ lib/strto.c | 11 ++++++----- test/str_ut.c | 2 ++ 3 files changed, 11 insertions(+), 5 deletions(-)
diff --git a/include/vsprintf.h b/include/vsprintf.h index d4bf3211da..5172ceedec 100644 --- a/include/vsprintf.h +++ b/include/vsprintf.h @@ -98,6 +98,9 @@ long long simple_strtoll(const char *cp, char **endp, unsigned int base); * Given a string this finds a trailing number on the string and returns it. * For example, "abc123" would return 123. * + * Note that this does not handle a string without a prefix. See dectoul() for + * that case. + * * @str: String to examine * Return: trailing number if found, else -1 */ diff --git a/lib/strto.c b/lib/strto.c index f191884376..b1d803a77d 100644 --- a/lib/strto.c +++ b/lib/strto.c @@ -189,11 +189,12 @@ long trailing_strtoln(const char *str, const char *end)
if (!end) end = str + strlen(str); - if (isdigit(end[-1])) { - for (p = end - 1; p > str; p--) { - if (!isdigit(*p)) - return dectoul(p + 1, NULL); - } + p = end - 1; + if (p > str && isdigit(*p)) { + do { + if (!isdigit(p[-1])) + return dectoul(p, NULL); + } while (--p > str); }
return -1; diff --git a/test/str_ut.c b/test/str_ut.c index 9674a59f2a..058b359437 100644 --- a/test/str_ut.c +++ b/test/str_ut.c @@ -257,6 +257,8 @@ static int str_trailing(struct unit_test_state *uts) ut_asserteq(123, trailing_strtoln(str1, str1 + 6)); ut_asserteq(-1, trailing_strtoln(str1, str1 + 9));
+ ut_asserteq(3, trailing_strtol("a3")); + return 0; } STR_TEST(str_trailing, 0);