Using eclipse based tools to z/OS

Eclipse based tools like z/OS Explorer and IBM Developer for z/OS, use a server on the z/OS system called RSED.

This is available on the ZD&T (ZPDT) system, but is hidden away.

You need to mount the file system

mount filesystem(‘FEK320.HALG320.ZFS’) mountpoint(‘/usr/lpp/IBM/zexpl/’)

Then start the server

s rsed

It’s easy when you know how.

ISPF has autocomplete – just like a laptop!

On Linux I can use “ls D” and tab, and it lists Documents/ and Downloads/ . If I type “ls Doc” and press tab it uses autocomplete to give “ls Documents/”. This is a great way to save you typing.

I’ve just found the same function for z/OS. It has been in the product since at least 2004!

  • Set up a pf key to be AUTOTYPE ( type KEYS on the command line) I set PF6 to this
  • Go to ISPF 3.4 and type the start of a data set, for example COLIN.
  • press PF6, it gives me COLIN.JCL, press PF6 again, it gives me COLIN.MP1B.JCL

Of course you could always type COLIN.* and press enter, then tab down the list. But I thought AUTOTYPE was pretty neat.

Setting PF Keys 13 to 24

When I went to set my PF key, I found all 12 keys were allocated. How do I set keys 13 to 24?
If you use PFSHOW TAILOR it allows you to use 12 or 24 keys, and to control what is displayed.

I have my terminal emulator set up so shift PF5 is PF17, and so I set PF17 to AUTOTYPE.


Using point and shoot keys in ISPF

ISPF has had hot keys for many years – I have only just got round to using them.

At the top of ISPF screens there is usually an action bar. For example

   Menu  Utilities  Compilers  Options  Status  Help                       
                   ISPF Primary Option Menu                           
 Option ===>                                                                   

Where the actions are Menu, Utilities etc. The underlined letter is the hot key for the action.

To select Utilities, type U on the command line and press the “Actions” PF key. This will do the same as tabbing to the Utilities action bar item, and pressing enter. For me PF10 is set to Actions.

You can display your PF Key settings using the keys or pfshow command.

For people who like to use short cuts, have your command line at the top, and use the “home” key. This will get you to the command line. So you can do: home, U, PF10 and quickly get to the Utilities action bar item.

Who develops standard?

When the GUI standards came out I wondered why the standard was to put the command line at the bottom, as there was no “go to command line” key, you had to do “Home”, then shift, tab (to do back tab). This was too many keystrokes for me.

ISPF reflists provide hot lists of datasets and files.

You can set up hot lists of data sets names to make it easier to use data sets and files in Unix Services. For example if your hot list of data sets is SYS1.PROCLIB, ADCD.Z245.PROCLIB, COLIN.PROCLIB, COLIN.C.SOURCE, you can get a list of these in ISPF 3.4 format, so you can quickly move between them, rather than have to keep using ISPF 3.4 and typing in the names of the data sets.

ISPF provides a list called REFLIST with the last 30 datasets or Unix files you referenced, so when you come back from holiday and cannot remember what you were working on, then the REFLIST will show you. Recalling Those Darn Dataset Names is an interesting article.

You can have a hot list of Unix Services files.

You can use the REFLISTD command, or go into ISPF 3.4, up to the action bar, and use the pull down to select REFLIST.
By default, this gives you the a list of the last 30 data sets you used.

Example output

File View Options Help .
────────────────────────────────────────────────────────────────────────────── .
ISRPDSNL Personal Data Set List DSLIST processed .
Command ===> 
Enter a list action to perform or select a data set entry to retrieve. .
Action: S=Save A=Save As D=Delete this list E=Extended Edit L=DSLIST U=UDLIST .
Action   Name    Description                  Created Referenced .
L        REFLIST Last 30 referenced data sets         22/04/26 11:45 .

Select Data Set, DSLIST Level or z/OS UNIX file Volume WS 
. 'COLIN.CBT503.FILE967' 
. /u/tmp/zpymqi/code/pymqi/MQMAP.h 

The data at the bottom of the display is what is in this list. You cannot do anything with these entries. You can have datasets as well as Unix files in the list

The action only applies to the List entry itself.

If you put an L in front of the REFLIST, you get into standard ISPF 3.4 data set list – with all of the data sets from the list. You can use all of the commands you know and love from this list. You can use option U to list all of the Unix files in the list.

You can also save this list, for example use “A” to create your own list (eg COLIN).

If you want to use this list you can use the command REFACTD COLIN, or go to ISPF 3.4, action bar, REFLIST

1. Current Personal Data Set List (COLIN)
2. List of Personal Data Set Lists

Option 2 gives

ISRPLTAB EFLIST             Personal Data Set Lists                List 1 of 2
Command ===>                                                  Scroll ===> PAGE
Action: O=Open  A=Save As  D=Delete  E=Edit  L=DSLIST  U=UDLIST               
Name      Description                  Created  Referenced
_ COLIN   colin's list                 22/04/26 22/04/26 11:55
_ REFLIST Last 30 referenced data sets          22/04/26 11:57

This allows you to pick a list, and specify if you want a data set list, or a Unix file list.

This is really handy – but not very well documented. It feels like it has not been written for the end users but from the IBM developers view point.

Configuring ISPF for new applications.

I found an interesting ISPF extension which I wanted to try out. But I could not find any documentation on how to install it. As usual I found out even more interesting stuff trying to document it.

Logging on to TSO.

When you logon to TSO you specify a procedure such as ISPFPROC. This procedure is in the SYS1.PROCLIB concatenation.  A user can have a default procedure specified in the RACF TSO segment. A user is given access to the RACF CLASS TSOPROC. (So you use a command like RDEFINE TSOPROC NEWPROC UACC(READ) )

This procedure allocates the datasets used by TSO and ISPF, for example ISPPLIB, ISPMLIB, ISPLLIB,ISPEXEC, SYSEXEC, SYSOUT.

If you are authorised you can create your own TSO procedure, and add your application’s data sets to the JCL. Most systems do not allow this.

When this JCL is executed you can pass parameters to it, for example

//             PARM=’%ISPFCL’                       

will cause the ISPFCL exec or clist to be executed.   This is usually in the SYS1.CLIST concatenation. You can specify PARM=’EXEC ”SYS1.CLIST(SPFALLOC)”’ and specify a data set.

You can use this

  1. To write a message to users
  2. Allocate additional data sets,
  3. Check the existence of a profile, and execute it.

User specific processing

With the clist specified in the PARM statement you can have code like

/* rexx */
address TSO
userid = userid()
zl =”‘”userid”.ZLOGON.CLIST'” /* so we get ‘colin.zlogon.clist’ */
if SYSDSN(zl) = “OK” then exec zlogon /* the userid.. and .clist default’ */

For my userid this would check to see if COLIN.ZLOGON.CLIST exists, and if so, it executes it.


Within this data sets you can have user specific processing, for example

/* Rexx */
say "in colin.zlogon.clist"
address ispexec

This will add the datasets to the specified library, for example adds the panel library COLIN.CUCI.ISPPLIB to ISPPLIB.

You can use “LIBDEF ISPPLIB” to “pop” the definitions back to what they were before the call.

Running your own application

If you have your own panel or application you want to use, you could use the following to set up the libraries and display Mypanel

address ispexec
/* afterwards reset things back */

What has been libdef-ed?

You can use the TSO command ISPLIBD to display the data sets that have been libdef-ed for the logical screen. Note each logical screen can have its own libdef statements – depending on the set up. See here for a description.

FTP to z/OS when your fingers forget

They say that large dinosaurs had a brain in the head, and a brain near the back legs, because it took too long for information from the feet to reach the brain. I’ve always thought that programmers have a brain in each hands so they can type when the brain is thinking of other things. The problem with this is when you do not use commands, the hand brains forget the commands, and you have to use the head brain. I experienced this trying to FTP a file to z/OS and my fingers would not type the commands I used to know and love!

The FTP daemon needs to be running, for example S FTPD.

FTP to z/OS

  • ftp
  • userid ….
  • password

Set up the environment

  • BIN

Setup the dataset parameters using the site command

site cyl pri=10 sec=10 recfm=fb lrecfl=80 blksize=3200 vol=(volid1,volid2)

You can specify size units

  • cyl
  • trk
  • blk

I could not see how to display the default “site” parameters, so if in doubt specify all the parameters.

Change directory ( HLQ) at the remote end

cd ‘COLIN’

Change directory at the local end

lcd /u/colin/

List directories ( HLQ) at the remote end



ls ‘COLIN.CBT.*’


125 List started OK
Volume Unit Referred  Ext Used Recfm Lrecl BlkSz Dsorg Dsname
C4USR1 3390 2022/04/22  1   45    FB    80  5600 PO    V502.FILE967.PDS
250 List completed successfully.

Send files

You can use PUT or GET; MPUT or MGET.

MPUT and MGET will prompt for each file. You can toggle the prompting using the prompt subcommand

Interactive mode off.

Interactive mode on.

Additional information

  • ? – displays a summary of the commands
  • help command – gives a short description of the command
  • quit – exit FTP

Impossible puzzles

I’ve been on holiday, visiting friends and family, and one of my friends gave me three impossible puzzles. I thought I would pass them on.

The impossible puzzle

X and Y are two different whole numbers greater than 1. Their sum is not greater than 100, and Y is greater than X. S and P are two mathematicians (and consequently perfect logicians); S knows the sum X + Y and P knows the product X × Y. Both S and P know all the information in this paragraph.

The following conversation occurs (both participants are telling the truth):

  • S says “P does not know X and Y.”
  • P says “Now I know X and Y.”
  • S says “Now I also know X and Y.”

What are X and Y?

The Seemingly Impossible “Guess The Number Logic Puzzle

I got this from Mind your decisions by Presh Talwalkar.

Alice and Bob are on a game show. Each is secretly told a whole, positive number. They are told the two numbers are consecutive, but neither knows the other person’s number. For example, if Alice is told 20, she does not know if Bob was told 19 or 21. And if Bob is told 21, he does not know if Alice was told 20 or 22. The point of the game is to guess the other person’s number. The game works as follows.

  • Alice and Bob cannot communicate with each other, and they are not allowed to plan their strategy either.
  • The two are in a room where a clock rings every minute.
  • After the clock rings, either player can call out a guess of the other player’s number, or they can stay silent.
  • The game continues until Alice or Bob makes a guess. After the first guess is made, the game ends.
  • Alice and Bob win $1 million each if the guess is correct, and they lose and get nothing if the guess is incorrect.

How should Alice and Bob play this game to have the best chance of winning? Each knows the other person is perfect at logical reasoning.

Pirates, and being thrown overboard

Some pirates caught a yacht on the high seas. The 8 people on the yacht were all logicians.

The pirate king said “Tomorrow I will put a red dot or a black dot on your forehead. You cannot see the dot, but every one else can. I will place you in a circle, so you can see every one else, and I will ask each of you in turn, if you have a red dot or a black dot. If you get it right – you live, if you get it wrong you walk the plank, and feed the sharks. Now go to the cell and plan your strategy, arr Jim lad”.

What strategy should they use to save most people.