The C source code character set is a superset of the ISO 646-1983
Invariant Code Set. To enable programs to be represented in the
reduced set, trigraph sequences are defined
to represent those characters not in the reduced set. A trigraph is
a three character sequence that is replaced by a corresponding single
character. Table 7-2 gives the complete list of trigraph sequences
and their replacement characters.
Table 7-2 Trigraph Sequences and Replacement Characters
Trigraph Sequence | Replacement |
|---|
??= | # |
??/ | \ |
??' | ^ |
??( | [ |
??) | ] |
??! | | |
??< | { |
??> | } |
??- | ~ |
Any ? that does not begin one of the trigraphs listed
above is not changed.
-notrigraph
Option |
 |
In the ANSI extended (-Ae) mode, trigraph translation is automatically done. The
option, -notrigraph will disable automatic translation
of trigraph sequences.
