About sysconf(_SC_GETPW_R_SIZE_MAX)

[Dmitry Sivachenko]

Hello!

(FreeBSD-10/stable).

According to sysconf(3), _SC_GETPW_R_SIZE_MAX is the valid argument to sysconf():

 _SC_GETPW_R_SIZE_MAX
             Suggested initial value for the size of the password entry
             buffer.

But the following test program fails:

#include <unistd.h>
#include <err.h>
#include <errno.h>
#include <stdio.h>

int main() {
  int buf_sz;

  errno=0;
  buf_sz = sysconf(_SC_GETPW_R_SIZE_MAX);
  printf("%d\n", buf_sz);
  warn("sysconf: ");
  return 0;
}

% ./a.out 
-1
a.out: sysconf: : Invalid argument


What is wrong?

Thanks!