Difference between revisions of "ON ERROR"

Revision as of 15:19, 23 June 2009

Class

Error Handling and Debugging

Purpose

Trap program errors

Syntax

ON ERROR [<command>]

See Also

DOSERROR(), DISPLAY CALLS, ERRNO(), ERROR(), LIST CALLS, MESSAGE(), ON ESCAPE, ON KEY, RETRY, SET ONERROR

Description

The ON ERROR command causes the specified <command> to be executed if an error is encountered in a program. If ON ERROR is specified without a <command>, then the default Recital/4GL behavior will be restored. By default, the Recital/4GL will stop execution at the error and an error.mem file will be created

<command>

The <command> can be any Recital/4GL command. After an error is encountered, the ERROR() function will return the error number, and the MESSAGE () function will return the error message. Specifying an '*' as the command causes any errors to be ignored, so should be used with caution. The RETRY command is often used with the ON ERROR trapping facility.

Example

procedure badfile
  on error
  set message to "File does not exist."
return to master
 
on error do badfile
use patrons

Products

Recital Database Server, Recital Mirage Server, Recital Terminal Developer