Gets a group database entry for a group ID.

    This function is supported on OpenVMS Integrity servers and
    Alpha only.

    Format

      #include  <types.h>

      #include  <grp.h>

      int getgrgid_r  (gid_t gid, struct group *grp, char *buffer,
                      size_t bufsize, struct group **result);

1 - Arguments

 gid

    The group ID of the group for which the group database entry is
    to be retrieved.

 grp

    Storage area to hold the retrieved group structure.

 buffer

    The working buffer that is able to hold the longest group entry
    in the database.

 bufsize

    The length, in characters, of buffer.

 result

    Upon successful return, result points to the retrieved group
    structure.

    Upon unsuccessful return, result is set to NULL.

2 - Description

    The getgrgid_r function updates the group structure pointed to
    by grp and stores a pointer to that structure at the location
    pointed to by result. The structure contains an entry from the
    group database with a matching gid. Storage referenced by the
    group structure is allocated from the memory provided with the
    buffer argument, which is bufsize characters in size. The maximum
    size needed for this buffer can be determined with the _SC_GETGR_
    R_SIZE_MAX parameter of the sysconf function. On error or if the
    requested entry is not found, a NULL pointer is returned at the
    location pointed to by result.

3 - Return Values

    0                  Successful completion.
    x                  On error, the function sets the return value
                       to one of the following:

                       o  EACCES - The user process does not have
                          appropriate privileges enabled to access
                          the user authorization file.

                       o  EIO - An I/O error has occurred.

                       o  EINTR - A signal was intercepted during
                          getgrgid.

                       o  EMFILE - OPEN_MAX file descriptors are
                          currently open in the calling process.

                       o  ENFILE - The maximum allowable number of
                          files is currently open in the system.

                       o  ERANGE - Insufficient storage was supplied
                          through the buffer and bufsize arguments
                          to contain the data to be referenced by the
                          resulting group structure.