getgroups - get group access list
int getgroups(int ngroups, gid_t gidset);
getgroups() gets the current group access list of the user process and
stores it in the array gidset. The parameter ngroups indicates the
number of entries which may be placed in gidset. No more than
NGROUPS_MAX, as defined in <<<<limits.h>>>>, is ever returned.
As a special case, if the ngroups argument is zero, getgroups()
returns the number of group entries for the process. In this case,
the array pointed to by the gidset argument is not modified.
The following call to getgroups() (see getgroups(2)) retrieves the
group access list of the calling process and stores the group ids in
int ngroups = NGROUPS_MAX;
ngrps = getgroups (ngroups, mygidset);
If successful, getgroups() returns a non-negative value indicating the
number of elements returned in gidset. If an error occurs, a value of
-1 is returned and errno is set to indicate the type of error.
getgroups() fails if any of the following conditions are encountered:
[EFAULT] gidset specifies an invalid address. The reliable
detection of this error is implementation dependent.
[EINVAL] The argument ngroups is not zero and is less than the
number of groups in the current group access list of
getgroups() was developed by HP and the University of California,
Hewlett-Packard Company - 1 - HP-UX Release 11i: November 2000
getgroups(): AES, SVID3, XPG3, XPG4, FIPS 151-2, POSIX.1
Hewlett-Packard Company - 2 - HP-UX Release 11i: November 2000