Deciphering C Declarations with 'cdecl'
2020-05-17 00:00:00 -0000
Sometimes C declarations can be a little tricky to pull apart.
Especially when it comes to pointers to functions, arrays, and
pointers to functions returning arrays of pointers to functions. Throw
in some const and you might really need some help. Thankfully,
there’s a utility for that.
If you’ve read Kernighan and Ritchie’s The C Programming
Language, you might remember cdecl. There’s an incomplete
version of it in the “Complicated Declarations” section of the book.
cdecl is a handy utility that explains C declarations:
cdecl> explain const char * const * const argv
declare argv as const pointer to const pointer to const char
cdecl> explain void (*(*foo)(void)[3])(void)
declare foo as pointer to function (void) returning array 3 of pointer
to function (void) returning void
If you’re on Ubuntu, there’s a package you can install:
$ sudo apt-get install cdecl
If you’re on the go, there’s also a handy web version:
Happy C programming!