Old statements for processing POSIX files

These statements for processing POSIX files are now only supported for reasons of compatibility. The statements listed in section “File processing” should be used in their place.

@XCOPY	Reads a POSIX file which is stored in a POSIX file system into the current work file.	F mode L mode
@XOPEN	Opens a POSIX file which is stored in a POSIX file system and reads it into the current work file.	F mode L mode
@XWRITE	Writes the content of the current work file into a POSIX file. The work file is retained.	F mode L mode