How to resolve the algorithm Determine if only one instance is running step by step in the REXX programming language

Published on 12 May 2024 09:40 PM
#Rexx

How to resolve the algorithm Determine if only one instance is running step by step in the REXX programming language

Table of Contents

Problem Statement

This task is to determine if there is only one instance of an application running. If the program discovers that an instance of it is already running, then it should display a message indicating that it is already running and exit.

Let's start with the solution:

Step by Step solution about How to resolve the algorithm Determine if only one instance is running step by step in the REXX programming language

Source code in the rexx programming language

/* Simple ARexx program to open a port after checking if it's already open */
IF Show('PORTS','ROSETTA') THEN DO           /* Port is already open; exit */
   SAY 'This program may only be run in a single instance at a time.'
   EXIT 5                                    /* Exit with a mild warning   */
   END
                 /* Open rexxsupport.library so that ports can be opened   */
IF ~Show('LIBRARIES','rexxsupport.library') 
   THEN CALL AddLib('rexxsupport.library',0,-30,0) 

IF ~OpenPort('ROSETTA')    THEN EXIT 10       /* Open port, end if it fails */

SAY 'Program is now running.'

DO FOREVER                                    /* Busyloop                   */
   /* Program stuff here */
   END

EXIT 0

You may also check:How to resolve the algorithm Jacobi symbol step by step in the Nim programming language
You may also check:How to resolve the algorithm Constrained genericity step by step in the ooRexx programming language
You may also check:How to resolve the algorithm Guess the number/With feedback (player) step by step in the Scheme programming language
You may also check:How to resolve the algorithm Greatest element of a list step by step in the WDTE programming language
You may also check:How to resolve the algorithm Guess the number step by step in the PureBasic programming language