cppi - 1.18-3 main

GNU cppi adjusts or checks the indentation of C and C++ preprocessor
directives in a file.
.
Indent the C preprocessor directives in FILE to reflect their nesting
and ensure that there is exactly one space character between each #if,
#elif, #define directive and the following token, and write the result
to standard output. The number of spaces between the `#' and the following
directive must correspond to the level of nesting of that directive.