Preprocessing Directives
Preprocessing directives are lines in your program that start with
The set of valid directive names is fixed. Programs cannot define new
preprocessing directives.
Some directive names require arguments; these make up the rest of the
directive line and must be separated from the directive name by whitespace. For example,
A preprocessing directive cannot be more than one line in normal
circumstances. It may be split cosmetically with Backslash-Newline, but that has no effect
on its meaning. Comments containing Newlines can also divide the directive into
multiple lines, but the comments are changed to Spaces before the directive is
interpreted. The only way a significant Newline can occur in a preprocessing
directive is within a string constant or character constant. Note that most C
compilers that might be applied to the output from the preprocessor do not accept
string or character constants containing Newlines.
The