HP OpenVMS Systems Documentation

Returns an integer value indicating whether the procedure verification setting is currently on or off. If used with arguments, the F$VERIFY function can turn the procedure and image verification settings on or off. You must include the parentheses after the F$VERIFY function whether or not you specify arguments.

Format

F$VERIFY ([procedure-value] [,image-value])

Return Value

Arguments

procedure-value

Specifies an integer expression with a value of 1 to turn procedure verification on, or a value of 0 to turn procedure verification off.

When procedure verification is on, each DCL command line in the command procedure is displayed on the output device. Procedure verification allows you to verify that each command is executing correctly.

If you use the procedure-value argument, the function first returns the current procedure verification setting. Then the command interpreter turns the procedure verification on or off, as specified by the argument.

image-value

Specifies an integer expression with a value of 1 to turn image verification on, or a value of 0 to turn image verification off.

When image verification is on, data lines in the command procedure are displayed on the output device.

Description

The lexical function F$VERIFY returns an integer value indicating whether the procedure verification setting is currently on or off. If used with arguments, the F$VERIFY function can turn the procedure and image verification settings on or off. You must include the parentheses after the F$VERIFY function whether or not you specify arguments.

Using the F$VERIFY function in command procedures allows you to test the current procedure verification setting. For example, a command procedure can save the current procedure verification setting before changing it and then later restore the setting. In addition, you can construct a procedure that does not display (or print) commands, regardless of the initial state of verification.

When you use the F$VERIFY function, you can specify zero, one, or two arguments. If you do not specify any arguments, neither of the verification settings is changed. If you specify only the procedure-value argument, both procedure and image verification are turned on (if the value is 1) or off (if the value is 0).

If you specify both arguments, procedure and image verification are turned on or off independently. If you specify the image-value argument alone, only image verification is turned on or off. If you specify the image-value argument alone, you must precede the argument with a comma (,).

You can also use the F$ENVIRONMENT function with VERIFY_PROCEDURE or VERIFY_IMAGE as the argument. With the F$ENVIRONMENT function, you can determine either the procedure or image verification setting; the F$VERIFY function determines only the procedure verification setting.

DCL performs the F$VERIFY function even if it appears after a comment character, if it is enclosed in single quotation marks (` '). This is the only processing that DCL performs within a comment.

Examples

$ SAVE_PROC_VERIFY = F$ENVIRONMENT("VERIFY_PROCEDURE") 
$ SAVE_IMAGE_VERIFY = F$ENVIRONMENT("VERIFY_IMAGE") 
$ SET NOVERIFY 
   .
   .
   .
$ TEMP = F$VERIFY(SAVE_PROC_VERIFY, SAVE_IMAGE_VERIFY) 
      

This example shows an excerpt from a command procedure. The first assignment statement assigns the current procedure verification setting to the symbol SAVE_PROC_VERIFY. The second assignment statement assigns the current image verification setting to the symbol SAVE_IMAGE_VERIFY.

Then, the SET NOVERIFY command disables procedure and image verification. Later, the F$VERIFY function resets the verification settings, using the original values (equated to the symbols SAVE_PROC_VERIFY and SAVE_IMAGE_VERIFY). The symbol TEMP contains the procedure verification before it is changed with the F$VERIFY function. (In this example, the value of TEMP is not used.)

$ VERIFY = F$VERIFY(0) 
   .
   .
   .
 $ IF VERIFY .EQ. 1 THEN SET VERIFY 
      

This example shows an excerpt from a command procedure that uses the F$VERIFY function to save the current procedure verification setting and to turn both procedure and image verification off. At the end of the command procedure, if procedure verification was originally on, both the procedure and image verification are turned on.