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GETGROUPLIST(3)          BSD Library Functions Manual          GETGROUPLIST(3)

NAME
     getgrouplist -- calculate group access list

LIBRARY
     Standard C Library (libc, -lc)

SYNOPSIS
     #include <unistd.h>

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

DESCRIPTION
     The getgrouplist() function reads through the group file and calculates 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 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.

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().

BSD                              June 9, 1993                              BSD