Open a file for reading
#include <io.h>
int io_readfile(int64* d,const char* s);
io_readfile sets d to the number of a new descriptor reading from the disk file named s, and returns 1.
If something goes wrong, io_readfile sets errno to indicate the error, and returns 0; it does not create a new descriptor, and it does not touch d.
io_createfilefile(3), io_appendfile(3), io_readwritefile(3)