Change the current process‘s real and effective group ID to that specified by integer. Returns the new group ID. Not available on all platforms.

   [Process.gid, Process.egid]          #=> [0, 0]
   Process::GID.change_privilege(33)    #=> 33
   [Process.gid, Process.egid]          #=> [33, 33]

Returns the effective group ID for this process. Not available on all platforms.

   Process.egid   #=> 500

Set the effective group ID, and if possible, the saved group ID of the process to the given integer. Returns the new effective group ID. Not available on all platforms.

   [Process.gid, Process.egid]          #=> [0, 0]
   Process::GID.grant_privilege(31)     #=> 33
   [Process.gid, Process.egid]          #=> [0, 33]

Exchange real and effective group IDs and return the new effective group ID. Not available on all platforms.

   [Process.gid, Process.egid]   #=> [0, 33]
   Process::GID.re_exchange      #=> 0
   [Process.gid, Process.egid]   #=> [33, 0]

Returns true if the real and effective group IDs of a process may be exchanged on the current platform.

Returns the (real) group ID for this process.

   Process.gid   #=> 500

Returns true if the current platform has saved group ID functionality.

Switch the effective and real group IDs of the current process. If a block is given, the group IDs will be switched back after the block is executed. Returns the new effective group ID if called without a block, and the return value of the block if one is given.