DCL_CTLFLAGS is a bit mask system parameter 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.
|0||If clear (the default), the numeric portion of a system-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.
|1||Controls the token size used by DCL. If clear (the 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.
|2||If clear (the default), the numeric portion of a system-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.|
|3||If clear (the default), command procedure supports the 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.|
|4||This bit controls the the maximum length for an user name, 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. 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.|