> The return value should have been an error code and the actual long should have been "returned" via a pointer.
Oh, you mean like:
int ret = sscanf (str, "%d", &value);
?Oh, you mean like:
int ret = sscanf (str, "%d", &value);
?> Use of the numeric conversion specifiers produces Undefined Behavior for invalid input. See C11 7.21.6.2/10 ⟨https://port70.net/%7Ensz/c/c11/n1570.html#7.21.6.2p10⟩. This is a bug in the ISO C standard, and not an inherent design issue with the API. However, current implementations are not safe from that bug, so it is not recommended to use them. Instead, programs should use functions such as strtol(3) to parse numeric input. This manual page deprecates use of the numeric conversion specifiers until they are fixed by ISO C.
As the other poster points out, the bug is in the spec, and I'd be astonished if the library function itself actually misbehaves with any given input.
> However, current implementations are not safe from that bug, so it is not recommended to use them. Instead, programs should use functions such as strtol(3) to parse numeric input. This manual page deprecates use of the numeric conversion specifiers until they are fixed by ISO C.
In other words, sscanf itself is not safe to use for numeric conversions.
Why should you care? Depends. Do you care about writing correct programs? If not, there's no need to care.