getgroups(2) [ultrix man page]
getgroups(2) System Calls Manual getgroups(2) Name getgroups - get group access list Syntax #include <sys/types.h> #include <unistd.h> int getgroups(gidsetsize, grouplist) int gidsetsize; int grouplist[]; Description The call gets the current group access list of the user process and stores it in the array of int grouplist. The gidsetsize parameter indicates the number of entries that can be placed in grouplist. Return Values Upon success, the call returns the number of groups as the value of the function. No more than NGROUPS, as defined in <sys/param.h>, are returned. A value of -1 indicates that an error occurred, and the error code is stored in the global variable, errno. Diagnostics The call fails under the following conditions: [EINVAL] The gidsetsize argument is smaller than the number of groups in the group set. [EFAULT] The grouplist argument specifies invalid addresses. Environment POSIX When your program is compiled in the POSIX environment, the grouplist argument should be defined as follows: gid_t grouplist[]; Additionally, in the POSIX environment, if the gidsetsize argument is zero, returns the number of supplemental group IDs associated with the calling process, without modifying the array pointed to by the grouplist argument. See Also setgroups(2), initgroups(3x) getgroups(2)
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getgroups(2) System Calls getgroups(2) NAME
getgroups, setgroups - get or set supplementary group access list IDs SYNOPSIS
#include <unistd.h> int getgroups(int gidsetsize, gid_t *grouplist); int setgroups(int ngroups, const gid_t *grouplist); DESCRIPTION
The getgroups() function gets the current supplemental group access list of the calling process and stores the result in the array of group IDs specified by grouplist. This array has gidsetsize entries and must be large enough to contain the entire list. This list cannot be larger than NGROUPS_MAX. If gidsetsize equals 0, getgroups() will return the number of groups to which the calling process belongs without modifying the array pointed to by grouplist. The setgroups() function sets the supplementary group access list of the calling process from the array of group IDs specified by grou- plist. The number of entries is specified by ngroups and can not be greater than NGROUPS_MAX. RETURN VALUES
Upon successful completion, getgroups() returns the number of supplementary group IDs set for the calling process and setgroups() returns 0. Otherwise, -1 is returned and errno is set to indicate the error. ERRORS
The getgroups() and setgroups() functions will fail if: EFAULT A referenced part of the array pointed to by grouplist is an illegal address. The getgroups() function will fail if: EINVAL The value of gidsetsize is non-zero and less than the number of supplementary group IDs set for the calling process. The setgroups() function will fail if: EINVAL The value of ngroups is greater than {NGROUPS_MAX}. EPERM The {PRIV_PROC_SETID} privilege is not asserted in the effective set of the calling process. USAGE
Use of the setgroups() function requires the {PRIV_PROC_SETID} privilege. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Interface Stability |getgroups() is Standard. | +-----------------------------+-----------------------------+ |MT-Level |Async-Signal-Safe | +-----------------------------+-----------------------------+ SEE ALSO
groups(1), chown(2), getuid(2), setuid(2), getgrnam(3C), initgroups(3C), attributes(5), privileges(5), standards(5) SunOS 5.10 1 Feb 2003 getgroups(2)