fusl/src/passwd/putpwent.c

#define _GNU_SOURCE
#include <pwd.h>
#include <stdio.h>

int putpwent(const struct passwd* pw, FILE* f) {
  return fprintf(f, "%s:%s:%d:%d:%s:%s:%s\n", pw->pw_name, pw->pw_passwd,
                 pw->pw_uid, pw->pw_gid, pw->pw_gecos, pw->pw_dir,
                 pw->pw_shell) < 0
             ? -1
             : 0;
}