getgrouplist(3) - NetBSD Manual Pages

GETGROUPLIST(3)           NetBSD Programmer's Manual           GETGROUPLIST(3)


NAME

     getgrouplist - calculate group access list


LIBRARY

     Standard C Library (libc, -lc)


SYNOPSIS

     #include <unistd.h>

     int
     getgrouplist(const char *name, gid_t basegid, gid_t *groups,
             int *ngroups);


DESCRIPTION

     The getgrouplist() function reads through the group database and calcu-
     lates the group access list for the user specified in name.  The basegid
     is automatically included in the groups list.  Typically this value is
     given as the group number from the password database.

     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.

     Duplicate group ids will be suppressed from the result.


RETURN VALUES

     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.


FILES

     /etc/group  group membership list


SEE ALSO

     setgroups(2), initgroups(3)


HISTORY

     The getgrouplist() function first appeared in 4.4BSD.


BUGS

     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().

     In the case where the group array is too small and duplicate gids have
     been suppressed, the returned ngroups will be too large by a factor of
     the difference between the given size and the number of matches.  This is
     not considered to be a major problem, since it's still going to be a
     smaller figure than when duplicates were not suppressed.

NetBSD 1.6                      April 25, 1999                               1