io_readfile − open a file for reading
#include <libowfat/io.h>
int io_readfile(int64* d,const char* filename);
io_readfile sets d to the number of a new descriptor reading from the disk file named filename, 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_createfile(3), io_appendfile(3), io_readwritefile(3)