Jane.doe: Created page with "'''ON''' is a command that performs a specified action when a command or program executed within a command procedure encounters an error condition or is interrupted by Ctrl/Y...."

2019-12-02T10:39:17Z

Created page with "'''ON''' is a command that performs a specified action when a command or program executed within a command procedure encounters an error condition or is interrupted by Ctrl/Y...."

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'''ON''' is a command that performs a specified action when a command or program executed within a command procedure encounters an error condition or is interrupted by Ctrl/Y. The specified actions are performed only if the command interpreter is enabled for error checking or Ctrl/Y interrupts (the default conditions). Use the ON command only in a [[Command Procedure|command procedure]]. ON is a command executed inside of [[DCL]]; no [[Image|image]] is invoked.

The default is ON ERROR THEN EXIT.

=Syntax=
ON condition THEN [$] command

==Conditions==
The following are valid conditions for the ON command:
* WARNING: return status of warning occurs ([[$SEVERITY]] equals 0).
* ERROR: return status of error occurs ([[$SEVERITY]] equals 2).
* SEVERE_ERROR: return status of error occurs ([[$SEVERITY]] equals 4).
* CONTROL_Y: Ctrl/Y character occurs on [[SYS$INPUT]].

ON overrides the default error processing, which means that when error conditions milder than specified by the ON statement occur, the command procedure displays the message and continues.

Once the ON command has been executed, the default action (ON ERROR THEN EXIT) is reinstated.

=Examples=
$ ON SEVERE_ERROR THEN CONTINUE
A command procedure that contains this statement continues to execute normally when a warning or error occurs during execution. When a severe error occurs, the ON statement signals the procedure to execute the next statement anyway. Once the statement has been executed as a result of the severe error condition, the default action (ON ERROR THEN EXIT) is reinstated.

[[Category:DCL Commands]]

ON - Revision history

Jane.doe: Created page with "'''ON''' is a command that performs a specified action when a command or program executed within a command procedure encounters an error condition or is interrupted by Ctrl/Y...."