This opens a file specified by the string qpath and allocates a fileHandle_t (just a typedef int) to that file.
This is then used in subsequent operations involving the file. The fsMode_t enumeration refers to the mode the file is opened in.
- FS_READ for reading the file. FS_WRITE will create the file qpath if it doesn't exist or 0 length it if it does.
- FS_APPEND allows writing to the end of an existing file.
- FS_APPEND_SYNC is similar to FS_APPEND except you can read from the file at the same time.
An int is returned representing the length of the file being opened.