1 @Executes a command procedure or requests the command interpreter to read subsequent command input from a specific file or device. Format @ filespec [parameter[,...]] 2 Parameters filespec Specifies either the input device or the file for the preceding command, or the command procedure to be executed. The default file type is COM. The asterisk (*) and the percent sign (%) wildcard characters are not allowed in the file specification. parameter[,...] Specifies from one to eight optional parameters to pass to the command procedure. The symbols (P1, P2, . . . P8) are assigned character string values in the order of entry. The symbols are local to the specified command procedure. Separate each parameter with one or more blanks. Use two consecutive quotation marks ("") to specify a null parameter. You can specify a parameter with a character string value containing alphanumeric or special characters, with the following restrictions: o The command interpreter converts alphabetic characters to uppercase and uses blanks to delimit each parameter. To pass a parameter that contains embedded blanks or literal lowercase letters, place the parameter in quotation marks. o If the first parameter begins with a slash (/), you must enclose the parameter in quotation marks (" "). o To pass a parameter that contains literal quotation marks and spaces, enclose the entire string in quotation marks and use two consecutive quotation marks within the string. For example, the command procedure TEST.COM contains the following line: $ WRITE SYS$OUTPUT P1 Enter the following at the DCL prompt ($): $ @TEST "Never say ""quit""" When the procedure TEST.COM executes, the parameter P1 is equated to the following string: Never say "quit" If a string contains quotation marks and does not contain spaces, the quotation marks are preserved in the string and the letters within the quotation marks remain in lowercase. For example, enter the following at the DCL prompt: $ @TEST abc"def"ghi When the procedure TEST.COM executes, the parameter P1 is equated to the following string: ABC"def"GHI To use a symbol as a parameter, enclose the symbol in single quotation marks (' ') to force symbol substitution. For example: $ NAME = "JOHNSON" $ @INFO 'NAME' The single quotation marks cause the value "JOHNSON" to be substituted for the symbol NAME. Therefore, the parameter "JOHNSON" is passed as P1 to INFO.COM. 2 Qualifier /OUTPUT /OUTPUT=filespec Specifies the name of the file to which the command procedure output is written. By default, the output is written to the current SYS$OUTPUT device. The default output file type is .LIS. The asterisk (*) and the percent sign (%) wildcard characters are not allowed in the output file specification. System responses and error messages are written to SYS$COMMAND as well as to the specified file. The /OUTPUT qualifier must immediately follow the file specification of the command procedure; otherwise, the qualifier is interpreted as a parameter to pass to the command procedure. You can also redefine SYS$OUTPUT to redirect the output from a command procedure. If you place the following command as the first line in a command procedure, output will be directed to the file you specify: $ DEFINE SYS$OUTPUT filespec When the procedure exits, SYS$OUTPUT will be restored to its original equivalence string. This produces the same result as using the /OUTPUT qualifier when you execute the command procedure. 2 Examples 1.$ CREATE DOFOR.COM $ ON WARNING THEN EXIT $ IF P1.EQS."" THEN INQUIRE P1 FILE $ FORTRAN/LIST 'P1' $ LINK 'P1' $ RUN 'P1' $ PRINT 'P1' <Ctrl/Z> $ @DOFOR AVERAGE This example shows a command procedure, named DOFOR.COM, that executes the FORTRAN, LINK, and RUN commands to compile, link, and execute a program. The ON command requests that the procedure not continue if any of the commands result in warnings or errors. When you execute DOFOR.COM, you can pass the file specification of the FORTRAN program as the parameter P1. If you do not specify a value for P1 when you execute the procedure, the INQUIRE command issues a prompting message to the terminal and equates what you enter with the symbol P1. In this example, the file name AVERAGE is assigned to P1. The file type is not included because the commands FORTRAN, LINK, RUN, and PRINT provide default file types. 2.$ @MASTER/OUTPUT=MASTER.LOG This command executes a procedure named MASTER.COM; all output is written to the file MASTER.LOG. 3.$ CREATE FILES.COM *.FOR, *.OBJ <Ctrl/Z> $ DIRECTORY @FILES This example shows a command procedure, FILES.COM, that contains parameters for a DCL command line. You can execute this procedure after the DIRECTORY command to get a listing of all Fortran source and object files in your current default directory. 4.$ CREATE QUALIFIERS.COM /DEBUG/SYMBOL_TABLE/MAP/FULL/CROSS_REFERENCE <Ctrl/Z> $ LINK SYNAPSE@QUALIFIERS This example shows a command procedure, QUALIFIERS.COM, that contains qualifiers for the LINK command. When you enter the LINK command, specify the command procedure immediately after the file specification of the file you are linking. Do not type a space between the file specification and the @ command. 5.$ CREATE SUBPROCES.COM $ RUN 'P1' - /BUFFER_LIMIT=1024 - /FILE_LIMIT=4 - /PAGE_FILES=256 - /QUEUE_LIMIT=2 - /SUBPROCESS_LIMIT=2 - 'P2' 'P3' 'P4' 'P5' 'P6' 'P7' 'P8' <Ctrl/Z> $ @SUBPROCES LIBRA /PROCESS_NAME=LIBRA This example shows a command procedure named SUBPROCES.COM. This procedure issues the RUN command to create a subprocess to execute an image and also contains qualifiers defining quotas for subprocess creation. The name of the image to be run is passed as the parameter P1. Parameters P2 to P8 can be used to specify additional qualifiers. In this example, the file name LIBRA is equated to P1; it is the name of an image to execute in the subprocess. The qualifier /PROCESS_NAME=LIBRA is equated to P2; it is an additional qualifier for the RUN command. 6.$ CREATE EDOC.COM $ ASSIGN SYS$COMMAND: SYS$INPUT $ NEXT: $ INQUIRE NAME "File name" $ IF NAME.EQS."" THEN EXIT $ EDIT/TPU 'NAME'.DOC $ GOTO NEXT <Ctrl/Z> $ @EDOC This procedure, named EDOC.COM, invokes the EVE editor. When an edit session is terminated, the procedure loops to the label NEXT. Each time through the loop, the procedure requests another file name for the editor and supplies the default file type .DOC. When a null line is entered in response to the INQUIRE command, the procedure terminates with the EXIT command. The ASSIGN command changes the equivalence name of SYS$INPUT for the duration of the procedure. This change allows the EVE editor to read input data from the terminal, rather than from the command procedure file (the default input data stream if SYS$INPUT had not been changed). When the command procedure exits, SYS$INPUT is reassigned to its original value.