GETGROUPLIST(3) BSD Programmer's Manual GETGROUPLIST(3)
getgrouplist - calculate group access list
#include <unistd.h> int getgrouplist(const char *name, gid_t basegid, gid_t *groups, int *ngroups);
The getgrouplist() function reads through the group file and calculates the group access list for the user specified in name. The basegid is au- tomatically included in the groups list. Typically this value is given as the group number from the password file. The resulting group list is returned in the integer array pointed to by groups. The caller specifies the size of the groups array in the integer pointed to by ngroups; the actual number of groups found is returned in ngroups.
The getgrouplist() function returns -1 if the size of the group list is too small to hold all the user's groups. Here, the group array will be filled with as many groups as will fit.
/etc/group group database file
setgroups(2), initgroups(3)
The getgrouplist() function first appeared in 4.4BSD.
The getgrouplist() function uses the routines based on getgrent(3). If the invoking program uses any of these routines, the group structure will be overwritten in the call to getgrouplist(). MirBSD #10-current June 9, 1993 1