HH&S product

EVMPR VM/CMS REXX emulator for UNIX/Windows

VM/CMS-style runtime for REXX on UNIX, Linux and Windows.

VM/CMS emulator for REXX - Version 2.21

SUMMARY

WHAT IS EVMPR
RECOMMENDED HARDWARE
SOFTWARE REQUIREMENTS
VM/CMS SUPPORTED COMMANDS

General commands

GLOBALV command

EXEC command

I/O

Overview

ERASE command

RENAME command

COPY command

STATE command

LISTFILE command

EXECIO command

Pipes and Pipe stages (filters)

Overview

ADDSTREAM command

ADDPIPE command

ENDPIPE command

SELECT command

OUTPUT command

READTO command

DROP stage

TAKE stage

CHANGE stage

LITERAL stage

FANIN stage

Recognized but ignored commands
BINARY FILE PROCESSING USING PIPES
INTEGRATING VM/CMS PROCEDURES IN EVMPR

Integrating EVMPR engine in your procedures
General REXX programs adaptation
File System adaptation
Pipes adaptation
System Calls adaptation
Script wrapper
INCIDENTS

1 - What is EVMPR

EVMPR is a VM/CMS REXX emulation runtime for Unix/Windows running "as is" your original CMS REXX programs on inexpensive Unix/Windows and shooting your monthly IBM host fees.

It is composed of :

a command runtime implemented by a shared library
a command set simulating some specific VM/CMS features, implemented by programs and scripts.
For NT platform, gzip and gunzip programs (ported and distributed by HHNS under GPL Zlib license)

2 - Recommanded Hardware

Windows and Linux platform

- CPU Pentium III 400 Mhz minimum

- necessary storage capacity

IBM AIX platform

- CPU 53P minimum

- necessary storage capacity

3 - Pre-required Software

Windows/NT platform :

Windows/NT4 Server US, Service Pack 4 or 5
Ressource Kit NT4
Object Rexx IBM for Windows V1.03
FTP and RSH services for batch automation

AIX platform

AIX V4.3 minimum
Object Rexx IBM for AIX V6

LINUX platform

LINUX kernel 2.4 and above
Run time libc5
Object Rexx IBM for LINUX

Other UNIX platform

We can port to any POSIX UNIX

4 - VM/CMS supported commands

General Commands

GLOBALV command

syntax :
"GLOBALV SELECT env SETP variable value"

"GLOBALV SELECT env GET variable"
limitations : in this version, environment is not saved, nor processed.
It is only simulated during the procedure.
example :
"GLOBALV SELECT MYAPPL SETP RETRC" retrc

"GLOBALV SELECT MYAPPL GET RETRC"

EXEC command

syntax : "EXEC command arguments"
implementation :
Searches 'PATH' system variable for :
- command.EXEC

- command.REXX

then transmits the command to system
limitations : Operating System's limitations

I/O

Abstact :

VM/CMS filesystem is simulated :

'fn ft fm' notation is accepted as is by supported commands, Windows/Unix traditionnal 'path' standing as 'filemode' (default : ./ or .\).

examples : 'name extens /path/data'( VM) = '/path/data/name.extens' (Unix)

'name extens' (VM) = './name.extens' (Unix)

Limitations are operating system's limitations (metasymbols % or $, &, ...)

The wildcard notation (*) is supported except in the filemode.

ERASE command

syntax : "ERASE fn ft fm"
limitations : Operating System's limitations
examples :

"ERASE AB* *CD* /path/data " (Unix)
"ERASE AB* *CD* U:\path\data" (Windows)

RENAME command

syntax : "RENAME fn1 ft1 fm fn2 ft2 fm"
abbrev. : "REN"
limitations : Operating System's limitations
examples :

"REN ABC DEF /path/data UVW = =" (Unix)
"REN ABC DEF /path/data = -DEF =" (Unix)
"REN ABC DEF U:\path\data XYZ = =" (Windows)
"REN ABC DEF U:\path\data = DEF2 =" (Windows)

COPY command

syntax : "COPY fn1 ft1 fm1 fn2 ft2 fm2"
limitations : Operating System's limitations
examples :

"COPY ABC DEF /path/data UVW = =" (Unix)
"COPY ABC DEF /path/data = = /tmp" (Unix)
"COPY ABC DEF U:\path\data XYZ = = " (Windows)
"COPY ABC DEF U:\path\data = = V:\tmp" (Windows)

STATE command

syntax : "STATE fn ft fm"
limitations : no generic metacharacter ('*', '?', '=') in filemode
examples :

"STATE ABC DEF /path/data" (Unix)
"STATE *ABC* * /path/data" (Unix)
"STATE ABC DEF U:\path\data" (Windows)
"STATE *ABC* * U:\path\data" (Windows)
if rc = 28 then ... /* does not exist */

LISTFILE command

syntax : "LISTFILE fn ft fm [( ALL/DATE/LABEL STACK/LIFO ]"
abbrev. : "LISTF"
limitations : Operating System's limitations
examples :

"LISTF ABC DEF /path/data ( ALL STACK" (Unix)

"LISTF ABC DEF U:\path\data (DATE LIFO" (Windows)

EXECIO command

DISKR function syntax :
"EXECIO n|* DISKR fn ft fm"

"EXECIO n|* DISKR fn ft fm [( LIFO ]"

"EXECIO n|* DISKR fn ft fm ( STEM stname]"

"EXECIO 1 DISKR fn ft fm ( VAR varname]"
DISKW function syntax :
"EXECIO n|* DISKW fn ft fm"

"EXECIO n|* DISKW fn ft fm ( STEM stname]"

"EXECIO 1 DISKW fn ft fm ( VAR varname]"

"EXECIO 1 DISKW fn ft fm ( CONST xxxxxx"
CP function syntax :
"EXECIO n|* CP ( [STACK | LIFO | FIFO ] CONST xxxxxx ..."
limitations :
on current version, data files are ascii text, binary is not processed

CP command simulation is made by submiting the command 'as is' to the system, then redirecting results (standard output) into stack
examples :

EXECIO 5 DISKR fn1 ft1 fm1 ( STEM S1."

EXECIO 1 DISKR fn1 ft1 fm1 ( VAR VVV"

EXECIO * DISKR fn1 ft1 fm1

EXECIO * DISKW fn2 ft2 fm2

EXECIO * DISKW fn2 ft2 fm2 ( STEM S1.

EXECIO 1 DISKW fn2 ft2 fm2 ( VAR vvv

EXECIO 1 DISKW fn3 ft3 fm3 ( CONST this is a litteral

EXECIO * CP ( CONST dir /o

EXECIO * CP ( LIFO CONST grep aaa /tmp/ffff.eeeee

EXECIO * CP ( CONST df -v

Pipes and Pipe stages (filters)

Abstact :

VM/CMS Pipe is implemented by EVMPR with Unix and Windows equivalents :

Each pipe stage is a filter that reads on standard input (stdin) and writes to standard output (stdout).

This makes it possible to replace a VM/CMS missing stage by its Unix/Windows equivalent, generaly present inside the system or easy to make.

When these stages are REXX procedure REXX, they are called by :

"rexx stage.REXX [arguments ...".

PIPE command

syntax:
"PIPE < fn1 ft1 fm1 | stage1 | stage2 ... | > fn2 ft2 fm2"

"PIPE | STEM XXX. | ...."

"PIPE | VAR VVV | ...."

"PIPE < fn1 ft1 fm1 | stage1 | stage2 ... | STEM XXX."

"PIPE < fn1 ft1 fm1 | stage1 | stage2 ... | VAR VVV"

limitations : only above specified syntaxes are accepted.
check EVMPR supported Stage list below.
examples :

"PIPE < ABCDE DATA | take 1 | VAR abcde_data"

"PIPE <" fn ft fm "| drop 1 | STEM abc."

"PIPE < ABC DATA | rexx prog1.rex ( opt1 | > ABC LOGFILE"

ADDSTREAM command

syntax : "ADDSTREAM OUTPUT alias"
limitations : the INPUT direction is not implemented on this version.
example : check the SELECT command below

ADDPIPE command

syntax : "ADDPIPE *.OUTPUT.alias: | > fn ft fm"
limitations :

- the INPUT direction is not implemented on this version.
- file ('fn ft fm') is associated to alias and open for output

example : check the SELECT command below

ENDPIPE command

syntax : "ENDPIPE alias"
limitations : immediate and definitive close of file associated to alias

SELECT command

syntax : "SELECT OUTPUT alias"
limitations : the INPUT direction is not implemented on this version.
the file associated to 'alias' becomes the current output file
example :

"ADDSTREAM OUTPUT myout1"

"ADDPIPE *.OUTPUT.myout1 : | > F123456 RESULT ."

"SELECT OUTPUT myout1"

"OUTPUT 1rst line of file F123456.RESULT"

...

"ENDPIPE myout1"

OUTPUT command

syntax : "OUTPUT" expression
limitations :

without 'SELECT' issued beofre, default output will be on standard output

a 'newline' is added to the expression

Binary possibily (check the 'Binary Processing' topic below)

example : check the SELECT command above

READTO command

syntax : "READTO variable"
limitations :

in this version, reading is through standard input, by text ligne

Binary possibily (check the 'Binary Processing' topic below)

example :

do forever

"READTO ligne"

if rc <> 0 then leave /* End Of File on stdin */

...

end

DROP stage

syntax : "PIPE < ... | DROP n | ..."
limitations : this stage has a meaning only for text standard input
example : check 'Pipe example' below

TAKE stage

syntax : "PIPE < ... | TAKE n | ..."
limitations : this stage has a meaning only for text standard input
example : check 'Pipe example' below

CHANGE stage

syntax 1 : "PIPE < ... | CHANGE -x hh-hh | ..."
limitations : 'hh-hh' notation means 2 characters hexadecimal
syntax 2 : "PIPE < ... | CHANGE [(col1-col2) /scr1/tgt1/ [/src2/tgt2/ ...]"
limitations : /src/tgt/ notation only accepts ASCII strings
examples :
"PIPE <" filein "| change -x 00-20 | >" fileout /* Zero Bin. to spaces */

"PIPE <" filein "| change /ALBERT/ANATOLE/ | >" fileout

"PIPE <" filein "| change (28-30) /A1/B4/ /A2/B5/ | >" fileout

LITERAL stage

syntax :
'PIPE < ... | LITERAL "'expression'" | ...'

'PIPE | LITERAL -n "'expression'" | ...'
limitations :
the -n flag indicates there is no input to the pipe

RESPECT OF SINGLE QUOTES AND DOUBLE QUOTES IS IMPORTANT
examples :
'PIPE <' filein '| literal "My Result Header" | >' fileout

'PIPE | literal -n "My Result Header" | >' fileout

'PIPE | literal -n "'right('Etat n.' n, 72)'" | >' fileout

FANIN stage

This stage simulated 'the best it can' VM/CMS multiples pipes merging It merges one or many file(s) with standard input
syntax :
'PIPE < ... | FANIN fn1 ft1 fm1 fn2 ft2 fm2 ... | ...'

'PIPE < ... | FANIN -r fn1 ft1 fm1 fn2 ft2 fm2 ... | ...'
limitations : the -r flags indicates the file(s) given as parameters are written to output BEFORE the standard input stream.
examples :
'PIPE <' filein '| fanin' wfile '| >' fileout /* first filein, then wfile */

'PIPE <' filein '| fanin -r wfile '| >' fileout /* first wfile, then filein */

Recognized but ignored commands :

SET (except SET SYSIN/SYSOUT)
MAKEBUF
DESBUF
DROPBUF

5 - Binary File processing using Pipes

Processing a stage input/output as binary is possible (no newline)

In order to do this, we assume data type is 'VARIABLE UNBLOCKED' (RECFM V), conforming to IBM Standard format.

EVMPR supplied 'SET SYSIN' et 'SET SYSOUT' pseudo-commands, handle this data type

SET SYSIN and SET SYSOUT commands

syntax : 'SET SYSIN/SYSOUT RECFM=ff' [LRECL=nnn si F or FB]
limitations : following RECFM are accepted by this version :

RECFM=V for variable unblocked "EBCDIC"
RECFM=VB for variable blocked "EBCDIC"
RECFM=F for fixe unblocked "EBCDIC"
RECFM=FB for fixe blocked "EBCDIC" (= F)
RECFM=T for "ASCII" files (defaut)"

example :

"SET SYSIN RECFM=V"

do forever

"READTO Z" /* read as variable unblocked, without newline */

if rc <> = 0 then leave

"OUTPUT Z" /* write as text mode, including newline */

end

6 - Integrating VM/CMS procedures in EVMPR

Integrating EVMPR engine in your procedures

The following 2-commands header has to be in each REXX ou EXEC procedure running with the EVMPR runtime :

"rxsubcom register CMS orxcms orxcms"

address CMS

General REXX programs adaptation

1) change operator "^=" to "<>" ('not egal')

2) changer 'say ...' instructions of REXX stages to "EXEC NENU ..." (otherwise, they will be mixed to output stream)

3) get rid of 'trace ?i' in REXX stages (otherwise, they will be mixed to output stream)

File Systems adaptation

4) eliminate/change '$' (dollar) symbol in file name (Unix)

5) eliminate/change '%' (percent) symbol in file name (Windows)

6) Change 'FileMode' values to a valid path name in VM/CMS file names

Pipes adaptation

7) check the Pipe stages, replace them by a platform (Unix/Windows) equivalent

8) check multiples pipes (x:fanin), divide them into 2 distinct pipes, one producing a workfile, the other integrating the workfile via 'fanin'

9) do not forget to replace REXX stages by 'rexx stage_name.REXX'

System calls adaptation

10) prefixe system commands with 'ADDRESS CMD' (Windows) or 'ADDRESS bash' (LINUX) or 'ADDRESS ksh' (AIX)

11) take care to 'escape' magical characters and metasymbols in commands (UNIX)

Script wrapper

12) Shell scripts (.cmd ou .sh) wrapping allow to easily start an application main procedure (generaly a .EXEC)

they set up some environment variables ( fn ft fm ) and call the main procedure via a
rexx Procedure_name.EXEC arguments

7 - Frequent Incidents

1) Syntax : operator '^=' to remplace with <>

2) files not processed : filename/filetype > 8 car., filemode = 'A' ou 'B' ...

4) System commands syntax :

check transformation of 'fn ft fm' to 'fm/fn.ft' are correct
'escape' Unix metasymbols UNIX with backslash : $,[],*,?,() ...

For more information, contact us.