Allocating FTP input and output data sets

When you invoke the FTP command from TSO, a check is made to see whether a data set is allocated to INPUT. If a data set is allocated, subcommands are read from that data set rather than from your terminal. Similarly, a check is also made to see whether a data set is allocated to OUTPUT. If so, all FTP prompts and replies are written to that data set rather than to your terminal.

The record length and block size of the output data set can be any size. If the logical record length of the output data set is less than 100 bytes, some messages could be truncated or wrapped around to the next line.

If you create INPUT and OUTPUT data sets, use the following guidelines:

Specify the INPUT data set:
- Record format=FB.
- Logical record length=2080.
  The logical record length of the input data set can be any value in the range 80 - 2080.
- Block size is a multiple of logical record length.
Specify the OUTPUT data set:
- Record format=FB.
- Logical record length=160.
- Block size is a multiple of 160.
  Restriction: When the FTP Client API is invoked by an application program, INPUT and OUTPUT ddnames are not available to the created FTP client process. See the z/OS Communications Server: IP Programmer's Guide and Reference for a description of the FTP Client API.