Copyright (c) 1983 Regents of the University of California.
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@(#)getgroups.2 6.4 (Berkeley) 04/10/87

C 5 getgroups - get group access list

#include <sys/param.h>

ngroups = getgroups(gidsetlen, gidset)
int ngroups, gidsetlen, *gidset;

Getgroups gets the current group access list of the user process and stores it in the array gidset . The parameter gidsetlen indicates the number of entries that may be placed in gidset. Getgroups returns the actual number of groups returned in gidset . No more than NGROUPS, as defined in < sys/param.h >, will ever be returned. A successful call returns the number of groups in the group set. A value of -1 indicates that an error occurred, and the error code is stored in the global variable errno\|. The possible errors for getgroup are:

15 [EINVAL] The argument gidsetlen is smaller than the number of groups in the group set.

[EFAULT] The argument gidset specifies an invalid address.

setgroups(2), initgroups(3) The gidset array should be of type gid_t , but remains integer for compatibility with earlier systems.