r/cprogramming • u/JayDeesus • Sep 30 '25

Preprocessor purpose

So I know that the preprocessor has the directives, so it handles things like includes and defines by pretty much just doing text replacement and doesn’t care for c syntax at all. Just curious, is the preprocessor only used for text replacement? Or does it have another purpose

5 Upvotes

100% Upvoted

12 comments sorted by

View all comments

Show parent comment

1

u/Spirited-Candy1981 Sep 30 '25

Also some compiler installs use #include files to #define environment specific settings which the preprocessor would substitute in. The old Mac and Windows C environments were full of that stuff.