File processing

The file processing statements provide a uniform interface for all the file types supported by EDT (DMS files, library elements and POSIX files).
These statements therefore represent the preferred way of processing files. The old, nonuniform statements for the file types are now only supported for reasons of compatibility.

@CLOSE	Causes the current work file to be written back to disk or tape, opened SAM, ISAM or POSIX files or library elements to be closed and the work file to be deleted.	F mode L mode
@COPY (Format 1)	Reads an existing SAM, ISAM or POSIX file or a library element in full into the current work file. The work file does not have to be empty when this is done. After being read in, the file or library element is closed again.	F mode L mode
@DELETE (Format 3)	Deletes files or library elements.	F mode L mode
@OPEN (Format 1)	Opens an existing SAM, ISAM or POSIX file or a library element and reads it into the current work file or creates a new file and opens this for processing.	F mode L mode
@SHOW (Format 1)	Outputs a library's directory or a list of files from the BS2000 catalog or from a POSIX directory.	F mode L mode
@WRITE (Format 1)	Creates a new SAM, ISAM or POSIX file or a library element and writes the content of the current work file to the new file or overwrites an existing file with the content of the current work file or writes the content of the current work file back to a file opened using @OPEN (format 1). An opened file remains open when @WRITE is issued and the content of the work file is retained.	F mode L mode