port of redo-c to BetterC

[aquaratixc]

On Thursday, 10 June 2021 at 10:04:38 UTC, Dennis wrote:
> On Thursday, 10 June 2021 at 09:53:36 UTC, aquaratixc wrote:
>> there is a function ```redo_ifchange (int targetc, char ** 
>> targetv)``` inside which the ```char [targetc] skip;``` array 
>> is defined;
>
> That's a Variable-length array which D doesn't support.
> If `targetc` has an upper bound, you can use a static array 
> instead:
> ```D
> import core.stdc.stdlib;
>
> void redo_ifchange (int targetc, char ** targetv) {
>     char[4096] buf = void;
>     assert(targetc <= buf.length);
>     char* skip = buf.ptr;
>     // code
> }
> ```
>
> For larger sizes, you can use heap-allocation:
> ```D
> import core.stdc.stdlib;
>
> void redo_ifchange (int targetc, char ** targetv) {
>     char* skip = cast(char*) malloc(targetc * char.sizeof);
>     scope(exit) free(skip);
>     // code
> }
> ```
>
> And if you really want variable-size stack allocation, you can 
> use `alloca`:
> ```D
> import core.stdc.stdlib;
>
> void redo_ifchange (int targetc, char ** targetv) {
>     char* skip = cast(char*) alloca(targetc * char.sizeof);
>     // code
> }
> ```
> Though I don't recommend it.

Thanks. Its really helpful. However, as I said, there are still 
questions: in particular, there is one mistake that I could not 
resolve. When I try to copy, I get an error like this: ```
redo.o:redo.d:function _D4redo13redo_ifchangeFiPPaZv: error: 
undefined reference to 
'_D4core3sys5posixQk4wait9WIFEXITEDFNaNbNiNfiZb'
redo.o:redo.d:function _D4redo13redo_ifchangeFiPPaZv: error: 
undefined reference to 
'_D4core3sys5posixQk4wait11WEXITSTATUSFNaNbNiNfiZi'
collect2: ``` although i imported ```core.sys.posix.sys.wait```