REXX Tips & Tricks:Miscellaneous

This section contains some further useful information.

Using PMREXX

The syntax for PMREXX is:

 >>──PMREXX───┬────┬──┬─────────────┬─┬───────────┬─><
              ├─/Q─┤  └─rexxprogram─┘ └─parameter─┘
              └─/T─┘

Where:

/Q

Close PMREXX after the REXX program ends (no "The program has ended" message box)

/T

Start PMREXX in trace mode

rexxprogram

Name of the rexx program

parameter

Parameter for the REXX program

All parameters, except rexxprogram, are optional.

Using PMREXX with the parameter /Q is useful for simple programs which only need to show a PM messagebox (using RxMessageBox). For an example see Saving the Desktop (3.0)

(see Run a REXX program under a specific environment on how to force a program to run under PMREXX)

Please note that you cannot use OS/2 commands that change the environment in a REXX program running under PMREXX. You have to use a similar REXX function for that purpose (e.g. directory() instead of CD, VALUE() instead of SET, etc.).

Warning: The default address environment for a REXX program started via PMREXX in WARP 3 is PMREXX; the default environment in WARP 4 is CMD. Therefore, you cannot distinguish between the environments using ADDRESS() in WARP 4!

Note

see also PMPopup/2 if you only want to use simple dialog boxes in REXX programs.

The RXQUEUE filter

The purpose of the RXQUEUE filter is to copy the output of an OS/2 program into a REXX queue (The RXQUEUE filter is the external program RXQUEUE.EXE - not the built-in function RXQUEUE!) The syntax for RXQUEUE filter is:

>>──RXQUEUE──┬───────────┬──┬────────┬──────><
             └─queuename─┘  ├─/FIFO──┤
                            ├─/LIFO──┤
                            └─/CLEAR─┘

The RXQUEUE filter usually operates on the default queue named "SESSION". However, if an environment variable named "RXQUEUE" exists, the RXQUEUE value is used for the queue name.

Parameters

queuename

This is the name of the queue to use. The queue must already exist. The name of a queue can only contain the following characters: 'A'...'Z', '0'...'9', '.', '!', '?' and '_'. Lowercase letters are converted to uppercase letters.

/LIFO

Stacks items from STDIN last in, first out (LIFO) on a REXX queue.

/FIFO

Queues items from STDIN first in, first out (FIFO) on a REXX queue.

/CLEAR

Removes all lines from a REXX queue.

Note

Again, do not confuse the RXQUEUE filter with the RXQUEUE built-in function! Note further that you cannot use the RXQUEUE filter to write a REXX queue to STDOUT - you've to write a REXX program to do this task. (see Write the REXX Queue to STDOUT for an example).

Return code of the function ADDRESS

A REXX program can use the function ADDRESS to detect the current environment. Following is a list of environments I know about (see Passing parameter to Rexx Dialog programs and Run a REXX program under a specific environment for examples for using this function.):

Return code of ADDRESS	Environment	Comments
CMD	OS/2 REXX Interpreter; also Object REXX for Win95/WinNT	use PARSE SOURCE to distinguish between the interpreter: OS/2 REXX returns OS/2; Object REXX for WinNT returns WIN32
CMS	VM/ESA 1.1 REXX Interpreter
COMMAND	Bill's REXX for DOS IBM PC DOS 7 REXX Interpreter	Use PARSE VERSION to distinguish between the environments.
CPEDIT	CPEDIT, an XEDIT clone from IBM
CPICOMM	SAA common environment especially used with communications
DFS	Display File Systems
DOS	Bill's REXX for DOS IBM PC DOS 7 REXX Interpreter	Use PARSE VERSION to distinguish between the environments.
EPM	EPM, OS/2 Editor
GLOBE	PMGlobe 2.18	IBM EWS Graphic program from Mike Cowlishaw, IBM UK Laboratories
FLEETSTREET	FleetStreet v1.03	Msg Reader & Editor for Squish msg bases
INT2E	Bill's REXX for DOS
ispcir	OS/2 DialogManager, IBM
IPSEXEC	Tritus SPF, Tritus Inc.
ISREDIT	SPF/2, CTC
KEDIT	KEDIT, an XEDIT clone from Mansfield Software
ksh	IBM's AIX REXX	The value is independent from the current shell
MVS	OS/390 v1.2 (PGM=IRXJCL) REXX Interpreter
NULL	DrDialog	this is an alternate SubCommand-Handler for DrDialog programs
PMREXX	PMREXX, OS/2 PMREXX.EXE (see the warning in the section Using PMREXX)
REXXTERM	REXXTERM, Quercus Software
RXDLG	Rexx Dialog
SAY	DrDialog	this is an alternate SubCommand-Handler for DrDialog programs
STARTDOS	StartDOS	a program to start DOS VDMs by Monte Copeland
SYSTEM	Bill's REXX for DOS Mark Hesslings's Regina REXX for Windows NT	use PARSE SOURCE to distinguish between the interpreter: Bill's REXX returns MSDOS, Mark's REXX returns WIN32
TE2	TE/2, Oberon Software
THE	THE Hessling Editor by Mark Hessling	THE is an XEDIT clone for various operating systems
TSO	OS/390 v1.2 (TSO) REXX Interpreter
VISION	ObjectVision, Borland
UNIX	uniREXX on Solaris v2.6
ZOC	ZOC 2.x, Markus Schmidt	One of the best OS/2 terminal programs available!

Prevent REXX from creating a token image

Set the read-only attribute of REXX cmds for which the REXX interpreter should not create a token image (or copy them to a read-only disk or to a filesystem not supporting Extended Attributes).

"Undocumented" REXX functions

The following REXX functions to work with DBCS mixed Strings are only documented in the IBM: OS/2 2.0 Procedures Language/2 Reference Manual and in the Object-Oriented REXX online documentation:

• DBADJUST
• DBBRACKET
• DBCENTER
• DBLEFT
• DBRIGHT
• DBRLEFT
• DBRRIGHT
• DBTODBCS
• DBTOSBCS
• DBUNBRACKET
• DBVALIDATE
• DBWIDTH

Well, for the "normal" REXX programmer only two of these functions are interesting (The functions also work with SBCS strings):

Name       DBRLEFT( string, n {,option} ) 
Function   Delete n chars beginning with the first char 
Example    DBRLEFT( "ABCDEFG", 2 ) gives "CDEFG"
Note       The parameter option is only needed for DBCS strings)
           For SBCS strings you should not use this parameter.

Name       DBRRIGHT( string, n {,option} ) 
Function   Delete n chars beginning with the last char 
Example    DBRRIGHT( "ABCDEFG", 3 ) gives "ABCD"
Note       The parameter option is only needed for DBCS strings)
           For SBCS strings you should not use this parameter.