IBM Mainframe Forum

[walldorf65]

Hello,

I am a beginner of mainframes.
At the moment I am writing a study thesis about the C programming on the operating system z/OS.
I have to describe the difference between C on z/OS and on Linux/Windows, but I couldn't find any relevant material. Another issue are the interface to databases, transaction monitor and middleware, but I could find only informations that you can program for IMS and DB2 with C/C++. These informations are not enough, I need more background material. I looked for material but I could not find anything.

Can you name some key words or some literature which can help me, please? Thank you for your efforts.

Best Regards,

walldorf65

[dick scherrer]

Hello,

These informations are not enough, I need more background material.

If you tell us more specifically what you are looking for, someone may be able to post a useful reply. . .

How long/large is this thesis to be when completed? If you are not familiar with how the z/OS environment works, the task will be more about this than the C language. Much of the material i've seen assumes the reader is already familiar/fluent with the operating environment and only needs the specifics of some particular language or toolset.

You might expand your search to look for publications that talk about the difference between the IBM mainframe and the Linux/UNIX/Windows environments. Among the biggest differences my teams have found is that the collating sequence is not the same and that the mainframe used packed-decimal heavily while on the LUW systems it is far less common.

[dick scherrer]

The link Robert provided in the "other"/duplicate topic (which is being locked):

http://www-01.ibm.com/software/awdtools/czos/ would be a good place to start -- the C/C++ bookshelf for IBM z/OS.

[walldorf65]

Hello,

C programming and interface to another operating system is only one chapter of the thesis and it should be between 10 and 15 pages.

Until now, I had only find material about EBCDIC, ASCII and enhanced ASCII support. I don't want to list the difference of header files. Then I found sentences likes IMS or CICS can develop with C/C++, but that's not enough so I need more literature/material.
The Language Environment is another possibility, but is there similar environment for Linux/Windows?

I have problems to find material or literature which describe the difference between z/OS and Linux/Windows.

Thank you for your efforts.

Best Regards,

walldorf65

[enrico-sorichetti]

see ...
http://www.redbooks.ibm.com/abstracts/sg245992.html

there are quite a lot of similarities between the zOS Unix System Services and Linux
very little/none with Windows

and as far as the zOS side, well that's a completely different beast

the Language Environment is the set of rules and runtime Libraries
which make possible the interlanguage communication between different programming languages in the zOS environment

for a basic idea of the zOS environment I strongly suggest to read

http://www.redbooks.ibm.com/abstracts/sg246366.html

[Robert Sample]

First, you really need to define your terms better. There is z/OS, there is z/VM, there is Z/Linux operating systems for z machines, so are you referring to Linux running on z-architecture machines or are you talking about Linux running on Intel-architecture machines?

Further, you can go to http://www.ibm.com and use the Search function to find all the mainframe literature that is publicly available, such as http://publib.boulder.ibm.com/infocenter/cicsts/v3r1/index.jsp?topic=%2Fcom.ibm.cics.ts31.doc%2Fdfhp3%2Fdfhp3pb.htm which includes information about writing CICS programs using C/C++. This same reference includes material about Language Environment.

You need to be aware that direct comparisons between mainframes and Linux/Windows machines is difficult for many reasons. The architectures are different, the intended use is different, the approach to security is different -- although high-level languages such as COBOL or C/C++ can run on either platform with very few (or even no) differences. The 45+ year history of mainframes does give a tremendous base of data but finding it can be difficult at times.