The
initgroups() function uses the
getgrouplist(3) function to calculate the supplementary group IDs for the user specified in
name. This group list is then set up for the current process using
setgroups(2). The
basegid is automatically included in the group list. Typically this value is given as the group number from the password file.
If the groups database lists more than
NGROUPS groups for
name (including one for
basegid), the later groups are ignored.