Before your program can read, write, or otherwise manipulate a file, the
program must initiate access to that file by opening it with the HPFOPEN/FOPEN
intrinsic call. This call applies to both disk files and device files. This
chapter discusses how you can use HPFOPEN to open various types of files
supported by MPE/iX. Examples of program segments are provided to illustrate
HPFOPEN calls.
This chapter is divided into the following subjects:
how the file system opens a file
which to use: HPFOPEN or FOPEN?
opening a system-defined file
