procedure Append (var F: any_file; [FileName: String;] [BlockSize: Cardinal]);
Append opens a file for writing. If the file does not exist, it is created. If it does exist, the file pointer is positioned after the last element.
Like Rewrite, Reset 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.
Append, including the BlockSize parameter, is a Borland Pascal extension. ISO 10206 Extended Pascal has Extend instead. The FileName parameter is a GNU Pascal extension.
program AppendDemo; var Sample: Text; begin Assign (Sample, 'sample.txt'); Rewrite (Sample); WriteLn (Sample, 'Hello, World!'); { `sample.txt' now has one line } Close (Sample); { ... } Append (Sample); WriteLn (Sample, 'Hello again!'); { `sample.txt' now has two lines } Close (Sample) end.