HP 3000 Manuals HP 3000 Manuals
Opening a New Disk File SPL uses the MPE V intrinsic FOPEN to create and open disk files. FOPEN allows SPL to have complete control over the definition of a new file. It returns a file number, filenum, which is used to identify the access to this file for subsequent I/O operations by other intrinsics, such as FREAD and FWRITE. If an error occurs, FOPEN returns zero and sets the condition code to CCL. In HP C/XL, a file may be created and opened with the library functions open and fopen or with the MPE XL intrinsics FOPEN and HPFOPEN. The most preferred and portable is HP C/XL fopen, which returns a stream pointer that is used by all of the HP C/XL standard data formatting and character transfer functions, such as fscanf and fprintf. If fopen fails, it returns a null pointer. If you need the HP C/XL binary read and write functions, or more file creation control, the open function provides more system-specific capabilities, which make it less portable. open returns fildes, a 32-bit int file descriptor, which may be used to obtain both a stream pointer and a filenum file number.