Problem using FtpWebRequest to append to file on a mainframe

Question

I am using FtpWebRequest to append data to a mainframe file. Each record appended is 50 characters long, and I am adding them one record at a time.

In our development environment, we do not have a mainframe, so my code was written and tested FTPing to a Windows-based FTP site instead of a mainframe. Initially, I was writing each record using a StreamWriter (using the stream from the FtpWebRequest) and writing each record using WriteLine (which automatically adds a CR/LF to the end).

When we ran this for the first time in the test environment (in which we're writing to an actual MVS mainframe), our mainframe contact said the CR/LFs were not able to be read by his program (a green-screen mainframe program of some sort - he's sent me screen captures, which is all I know of it).

I changed our code to use Write instead of WriteLine, but now my code executes successfully (i.e no thrown exceptions) when writing multiple records, but no matter how many records we append, he is only able to "see" the first record - according to his mainframe program, there is only one 50-character record in the file.

I'm guessing that to fix this, I need to write some other line-delimiting character into the end of the stream (instead of CR/LF) that the mainframe will recognize as a record delimiter. Anybody know what this is, or how else I can fix this problem?

Answer 1

I actually had the exact same problem, and I fixed it by using just LF as the delimiter.

Also, on a side note, for sending the file I ended up writing a command line script and shelling out to the DOS ftp utility, because the built in .NET FTP class did not play nicely with how the mainframe formatted commands and the strange "directory" structure.