Understanding the C Preprocessor: Macros, Conditional Compilation, and File Inclusion
Predefined tokens
__FILE__ // current source filename
__LINE__ // current line number
__DATE__ // compilation date "Mmm dd yyyy"
__TIME__ // compilation time "hh:mm:ss"
__STDC__ // 1 if the compiler conforms to ISO C
Simple textual substitution
#define forever for (;;)
#define CASE break; case
#define reg r ...
Posted on Wed, 13 May 2026 05:48:26 +0000 by dancing dragon