Method lseek

libraries/AP_Filesystem/AP_Filesystem_FATFS.cpp:528–559

}

off_t AP_Filesystem_FATFS::lseek(int fileno, off_t position, int whence)
{
    FRESULT res;
    FIL *fh;
    errno = 0;

    FS_CHECK_ALLOWED(-1);
    WITH_SEMAPHORE(sem);

    // fileno_to_fatfs checks for fd out of bounds
    fh = fileno_to_fatfs(fileno);
    if (fh == nullptr) {
        errno = EMFILE;
        return -1;
    }
    if (isatty_(fileno)) {
        return -1;
    }

    if (whence == SEEK_END) {
        position += f_size(fh);
    } else if (whence==SEEK_CUR) {
        position += fh->fptr;
    }

    res = f_lseek(fh, position);
    if (res) {
        errno = fatfs_to_errno(res);
        return -1;
    }
    return fh->fptr;
}

static time_t fat_time_to_unix(uint16_t date, uint16_t time)
{