The system_fopenWA function opens the file identified by path in write-append mode and returns a valid file descriptor. Use this function to open those files to which your program will append data.
SYS_FILE system_fopenWA(char *path);
The system-independent file descriptor (SYS_FILE) if the open succeeded, or 0 if the open failed.
char *path is the file name.
system_errmsg, system_fopenRO, system_fopenRW, system_lseek, system_fread, system_fwrite, system_fwrite_atomic, system_flock, system_ulock, system_fclose