Proper way to get groups of a user in linux using C

Question

I want to know if there is any alternate C library for the unix command groups,

$ groups ---- lists all the group id's of the user.

There is a method called getgroups() but it returns the groups of the user this method. Is there a way to get groups for a particular user using C.

Answer 1

#include "<grp.h>"
int getgrouplist(const char *user, gid_t group, gid_t *groups, int *ngroups);