DCL_CTLFLAGS

   DCL_CTLFLAGS is a bit mask that alters default behavior for
   certain DCL-related functions on a systemwide basis. However,
   the default values satisfy the needs of most systems.

   Bits 0 and 2 control the formulation of system-generated process
   names for processes created using the SPAWN command or LIB$SPAWN
   library routine. They are provided for compatibility with
   behavior of prior OpenVMS versions. Note that you can eliminate
   the use of system-generated names by supplying your own process
   names.

   Bit 1 controls the token size used by DCL.

   Bit 3 controls the maximum number input parameters to command
   procedure.

   Bit 4 controls the the maximum length for an user name, for which
   OpenVMS mail forwarding address is set.

   DCL_CTLFLAGS bits are described in the following table.

   Bit   Description

   Bit   If clear (the default), the numeric portion of a system-
   0     generated spawned process name is generated randomly. If
         set, the numeric portion is generated sequentially starting
         with sequence number 1.

         The option of sequential generation is provided for
         compatibility with OpenVMS versions prior to Version
         7.3-1. However, this choice can be very expensive in
         performance terms because of the mechanism for finding
         the next available process name. This mechanism attempts to
         create all process names beginning with sequence number 1
         until it finds one that is unused.

         Random generation is the preferred choice because it
         results in a very high probability of finding a unique
         name on the first try.

   Bit   Controls the token size used by DCL. If clear (the
   1     default), this bit instructs DCL to use the traditional
         token size. A token cannot exceed 255 characters. If this
         bit is set, extended tokens are used. Extended tokens are
         4000 characters.

         Note that if you turn on extended tokens, file
         specifications can exceed 255 characters, which might
         require larger structures for parsing file specifications.


   Bit   If clear (the default), the numeric portion of a system-
   2     generated spawned process name has a maximum value of
         65535. If set, the numeric portion of the name has a
         maximum value of 255.

         The option of a maximum of 255 is provided for
         compatibility with OpenVMS versions prior to Version 8.3,
         when it was the only choice. The larger maximum allows many
         more unique spawned process names for a given process.
         For this reason, it is the preferred choice. However,
         the larger maximum uses two additional characters from
         the process name, which might make it more difficult to
         identify users uniquely by looking at their spawned process
         names. If this is an issue on your system, setting bit 2
         might be a better choice.


   Bit   If clear (the default), command procedure supports the
   3     default eight optional parameters (that is, (P1,P2,...P8)).
         If set, command procedure supports up to sixteen optional
         parameters (that is, (P1,P2,...P16)). This is also
         applicable when using the CALL command to transfer control
         to a subroutine.


   Bit   This bit controls the the maximum length for an user name,
   4     for which OpenVMS mail forwarding address is set. If clear
         (the default), user name string length is set to a maximum
         length of 31 characters. If set, user name string length is
         set to a maximum of 255 characters.

         Note: Once this bit is set, user name length is set to
         maximum of 255 characters. Even if this bit is cleared,
         the behavior remains unchanged, that is, supports user name
         length of 255 characters, but there is no way to reset it
         to 31 characters.