1.$ SET VERIFY = PROCEDURE In this example, procedure verification is turned on. If image verification was on, it remains on; if image verification was off, it remains off. 2.$ SET VERIFY $ INDEX == "$INDEX.EXE" $ CONTENTS == "$CONTENTS.EXE" $ TABLE == "$TABLE.EXE" $ SET NOVERIFY $ EXIT Procedure and image verification are turned on at the beginning of the command procedure so that the system displays all the command and data lines in the procedure as it reads them. At the end of the procedure, the SET NOVERIFY command restores the system default (no procedure or image verification). 3.$ PROC_VER = F$ENVIRONMENT("VERIFY_PROCEDURE") $ IMAGE_VER = F$ENVIRONMENT("VERIFY_IMAGE") $ HOLD_PREFIX = F$ENVIRONMENT("VERIFY_PREFIX") $ SET PREFIX "(!%T)" $ SET VERIFY . . . $ TEMP = F$VERIFY(PROC_VER, IMAGE_VER) $ SET PREFIX "''HOLD_PREFIX'" This command procedure uses the F$ENVIRONMENT lexical function to save the current procedure and image verification setting, as well as the current verification prefix string. The SET PREFIX command sets the verification prefix to be used in the current command procedure. It uses an FAO control string to produce the time each command is read by the command interpreter (DCL), surrounded by parentheses. Then the SET VERIFY command turns on both procedure and image verification. Subsequently, the F$VERIFY lexical function is used to restore the original verification settings. The SET PREFIX command returns the verification prefix to its previous setting. Note how the symbol HOLD_PREFIX is used in the SET PREFIX command. This preserves casing and special characters in the stored string. 4.$ SET VERIFY $ @TEST $ RUN AVERAGE 1 2 3 $ EXIT In this example, the SET VERIFY command turns procedure and image verification on. When the command procedure TEST.COM is executed interactively, the command lines and the data lines for the program AVERAGE are displayed on the terminal. The data lines were entered in the command procedure on lines that did not begin with the DCL prompt. 5.$ SET VERIFY $ COUNT = 1 $ IF P'COUNT' .NES. "" THEN GOTO &P'COUNT' . . . $ EXIT When this command procedure is executed interactively, the SET VERIFY command causes the command and data lines to be displayed. Symbols that are substituted during the first phase of symbol substitution (such as 'COUNT') are displayed by the SET VERIFY command, but other symbols are not. The following lines are displayed when this procedure is executed interactively: $ COUNT = 1 $ IF P1 .NES. "" THEN GOTO &P1 . . . Although these values are not displayed, the value for P1 is substituted during the third phase of symbol substitution, and the value for &P1 is substituted during the second phase.