explain_getgrouplist_or_die - get list of groups and report errors

       libexplain version 1.4
       Copyright (C) 2013 Peter Miller

                                                                                  explain_getgrouplist_or_die(3)

       The  explain_getgrouplist_or_die  function is used to call the getgrouplist(3) system call. On failure an
       explanation will be printed to stderr, obtained from the explain_getgrouplist(3) function, and  then  the
       process terminates by calling exit(EXIT_FAILURE).

       The explain_getgrouplist_on_error function is used to call the getgrouplist(3) system call. On failure an
       explanation  will  be  printed  to  stderr, obtained from the explain_getgrouplist(3) function, but still
       returns to the caller.

       user    The user, exactly as to be passed to the getgrouplist(3) system call.

       group   The group, exactly as to be passed to the getgrouplist(3) system call.

       groups  The groups, exactly as to be passed to the getgrouplist(3) system call.

       ngroups The ngroups, exactly as to be passed to the getgrouplist(3) system call.

       The  explain_getgrouplist_or_die  function  is  intended to be used in a fashion similar to the following
       example:
              explain_getgrouplist_or_die(user, group, groups, ngroups);

       explain_getgrouplist_or_die - get list of groups and report errors

       The  explain_getgrouplist_or_die  function  only  returns  on  success,  see  getgrouplist(3)  for   more
       information. On failure, prints an explanation and exits, it does not return.

       The explain_getgrouplist_on_error function always returns the value return by the wrapped getgrouplist(3)
       system call.

getgrouplist(3)
               get list of groups to which a user belongs

       explain_getgrouplist(3)
               explain getgrouplist(3) errors

       exit(2) terminate the calling process

       #include <libexplain/getgrouplist.h>
       void explain_getgrouplist_or_die(const char *user, gid_t group, gid_t *groups, int *ngroups);
       int explain_getgrouplist_on_error(const char *user, gid_t group, gid_t *groups, int *ngroups);