Re: MCH3601 error -- RPG400-L

Any ideas?  Are these functions no longer supported?  I called IBM
support and he could not find ANY references to these functions at all.
Is there a better way to access the IFS from RPG?

These functions are still supported. They're part of the ILE C runtimelibrary, not system APIs. But, they're definitely supported in thecontext of ILE C -- though IBM probably doesn't expect people to call themfrom RPG.

Here's a link to the refence manual in the V5R3 info center where itdocuments those functions:

http://publib.boulder.ibm.com/infocenter/iseries/v5r3/ic2924/books/sc415607.pdf

Also, I use those functions every day from my RPG programs (albeit, I havemy own prototypes, I didn't even realize that Jef had done an article onthem!) I don't have any problems.

I suspect that you're somehow corrupting memory. Maybe by specifying asize incorrectly like Barbara suggested, but maybe some other way. Hard toknow without seeing the code.

Is there a "better" way? Define "better.". There's a different way --using the Unix-type APIs. This might be "better" in that they're systemAPIs, so IBM supports them across all ILE languages. However, there's noequivalent to fgets() for reading CR/LF terminated strings, so you have toroll your own. Also, the fopen/fgets, etc APIs will buffer the data asit's read, which greatly improves performance on sequential reads, whereasthe POSIX APIs do not. So, I guess it really depends on what you'redoing.

Regarding your other question about large file support... the O_LARGEFILEkeyword tells the system to use 64-bit structures when the file is opened.Calling open64() actually does the same thing -- it sets the O_LARGEFILEflag for you, so you don't have to add it to the open. Otherwise,open64() and open() are identical.

When you do that, the parameters to read() and write() do not change. Theydo not use 64-bit numbers. Do you really need to read more than 2gb in asingle call to read()?! Or write more than 2gb in a single call towrite()? Don't forget, you can call those APIs in a loop.. you don'thave to load everything into memory at once!

But, if you do want to access the whole stream file as a block of memory,you might try using mmap().