Target Language Compiler

Output File Control

The structure of the output file control construct is

%openfile string optional-equal-string optional-mode
%closefile id
%selectfile id

%openfile

The %openfile directive opens a file or buffer for writing; the required string variable becomes a variable of type file. For example,

%openfile x                 /% Opens and selects x for writing. %/
%openfile out = "out.h"     /% Opens "out.h" for writing. %/

%selectfile

The %selectfile directive selects the file specified by the variable as the current output stream. All output goes to that file until another file is selected using %selectfile. For example,

%selectfile x               /% Select file x for output. %/

%closefile

The %closefile directive closes the specified file or buffer, and if this file is the currently selected stream, %closefile invokes %selectfile to reselect the last previously selected output stream.

There are two possible cases that %closefile must handle:

• If the stream is a file, the associated variable is removed as if by %undef.
• If the stream is a buffer, the associated variable receives all the text that has been output to the stream. For example,

%assign x = ""                     /% Creates an empty string. %/
%openfile x
"hello, world"
%closefile x /% x = "hello, world\n"%/

If desired, you can append to an output file or string by using the optional mode, a, as in

%openfile "foo.c", "a"             %% Opens foo.c for appending.

Object-Oriented Facility for Generating Target Code

Input File Control