Plan for redirecting files

The table in this topic shows the valid combinations of file redirections.

To use this chart, identify the file type that you want to override in the FROM-FILE columns, and the file type that you want to override in the TO-FILE column. The intersection specifies an I or O or both; this means that the substitution is valid for these two file types when used as input files or as output files.

For example, you can override a diskette output file with a tape output file, and a diskette input file with a tape input file. The chart refers to file type substitutions only. That is, you cannot change the program function by overriding an input file with an output file.

Table 1. File redirections. Valid file redirections are summarized in the following table:
To-File From-File
Printer intersystem communications function (ICF) Diskette Display Database Tape
Printer O* O O O O O
ICF   O   I/O O I   O I I/O O I   O I   O I
Diskette   O   O I O I O I O I O I
Display       O   I/O O I   O I I/O O I   O I   O I
Database   O   O I O I O I O I O I
Tape   O   O I O I O I O I O I
Notes:
  • I=input file O=output file I/O=input/output file
  • *=redirection to a different type of printer
Parent topic: Redirect files