CL Command Reference - CRTDSPF
CL Command List > CRTDSPF Reference
Description:
The Create Display File (CRTDSPF) command creates a display device file. The device file contains the file description, which identifies the device used and, optionally, the record formats used by the device (if specified in data description specifications (DDS)); the device file does not contain data. The display device file sends records to one or more display devices associated with the device file, and to receive records from the display devices.
The display file description contains of information that is specified in two places: (1) in the source file that contains the DDS (if used); and (2) in the CRTDSPF command. The DDS contains the specifications for each record format in the device file and for the fields in each record format.
The Change Display File (CHGDSPF) or Override Display File (OVRDSPF) command is used in a program to change or override the parameter values specified in the display file description; the override command must be run before the display file is opened by the program. Overridden values are changed only for the running of the program; once the program ends, the original parameter values specified for the display file are used.
Note: If an application program attempts to acquire a work station on a switched line and the line connection has been lost or has never been established, the application program waits indefinitely until the connection is established.
Examples:
Example 1: Specifying Default Optional Parameters
CRTDSPF FILE(DSPHIST) SRCFILE(PRSNNL/JOBHIST)
This command creates a display device file named DSPHIST which is stored in the current library using the source file named JOBHIST that is stored in the PRSNNL library. The defaults for all the other parameters are assumed. Only the device requesting the program that uses this device file (that is, *REQUESTER) is assigned to the device file. The level identifiers of the record formats are checked when the file is opened. The public has only object operational authority for the device file.
Example 2: Specifying DBCS Data Processing
CRTDSPF FILE(IGCDSP) SRCFILE(IGCLIB/IGCSRC) IGCDTA(*YES)
This command creates the display file IGCDSP from the source file IGCSRC in the library IGCLIB. The file processes double-byte character set (DBCS) data.