Different scanf behaviour compared to glibc

Different scanf behaviour compared to glibc

[Evgeni Stebaev]

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Hi!

sscanf returns 0 for the following code using musl, but glibc returns 1.
%15s cannot be used here since it stops on whitespace, but it's required to
get all remaining data after getting other fields with sscanf (not included
in this example).

#include <stdio.h>
#include <string.h>

int main(void) {
  char data[16];
  memset(data, '\0', sizeof(data));
  int res = sscanf("abcde", "%15c", data);
  printf("parse: %d %s\n", res, data);
  return 0;
}

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Re: Different scanf behaviour compared to glibc

[Rich Felker]

On Fri, Jul 07, 2017 at 10:53:34PM +0300, Evgeni Stebaev wrote:
> Hi!
> 
> sscanf returns 0 for the following code using musl, but glibc returns 1.
> %15s cannot be used here since it stops on whitespace, but it's required to
> get all remaining data after getting other fields with sscanf (not included
> in this example).
> 
> #include <stdio.h>
> #include <string.h>
> 
> int main(void) {
>   char data[16];
>   memset(data, '\0', sizeof(data));
>   int res = sscanf("abcde", "%15c", data);
>   printf("parse: %d %s\n", res, data);
>   return 0;
> }

This is a known glibc bug (at least #12701, maybe duplicated in
others) that they were historically unwilling to fix. musl's behavior
matches what's required by the C standard. You might be able to use %[
to achieve what you want.

Rich