CVS client on IBM mainframes?

Whether there is a CVS client for IBM mainframes seems to be a common question. As far as we know, no one has yet worked on writing/porting a client; this page is about what might be involved.

Java and jCVS

According to rumor, Java runs on mainframes and it uses the ASCII (rather than EBCDIC) character set. Therefore, one might expect that jCVS would work. The one catch is that it would presumably write files in the working directory in ASCII rather than EBCDIC.

C and the command line client

I don't know whether mainframe C compilers use ASCII internally or EBCDIC internally. The most convenient would be the former, with EBCDIC conversion on text I/O (similar to the way that Windows or VMS C libraries convert between the text file conventions for those platforms). If the compilers use EBCDIC internally, then you'd need to write code to correctly generate the various ASCII strings in the CVS protocol, which would be tedious if relatively straightforward.

Wayne_Johnson@candle.com reports having gotten the command line client to work (at least, pserver login and checkout) on MVS with the HFS file system (he reported adding EBCDIC conversion code, so I suppose it is the second of the two options above) (Feb 1999). Download his work (.ZIP archive, several megabytes).