procedure Reset (var F: any_file; [FileName: String;] [BlockSize: Cardinal]);
Reset opens an existing file for reading. The file pointer is positioned at the beginning of the file.
Like Rewrite, Append and Extend do, Reset accepts an optional second parameter for the name of the file in the filesystem and a third parameter for the block size of the file. The third parameter is allowed only (and by default also required) for untyped files. For details, see Rewrite.
Reset is defined in ISO 7185 Pascal. The BlockSize parameter is a Borland Pascal extension. The FileName parameter is a GNU Pascal extension.
program ResetDemo; var Sample: Text; s: String (42); begin Rewrite (Sample); { Open an internal file for writing } WriteLn (Sample, 'Hello, World!'); Reset (Sample); { Open it again for reading } ReadLn (Sample, s); WriteLn (s); Close (Sample) end.