Syntax in the source program

If a POSIX file is to be processed, the absolute pathname of the file must be specified (see the manual "POSIX Basics" [1 (Related publications)]) or the name must be qualified with *POSIX(filename).

If a BS2000 file is to be processed, the file name must be qualified with
/BS2/. As soon as a BS2000 file is accessed, the BS2000 functionality of the corresponding function applies. Deviations from the XPG4 functionality, if any, are indicated by the marker BS2000 in the left margin of all relevant descriptions.

Figure 1: Control options at source code level

The system() function can be controlled analogously. The only difference is that a command for the desired system environment is specified instead of a file name.