detectAndroidApiLevel

fn detectAndroidApiLevel(io: Io) !u32 {
    comptime if (builtin.os.tag != .linux) unreachable;

    var child = try std.process.spawn(io, .{
        .argv = &.{
            "/system/bin/getprop",
            "ro.build.version.sdk",
        },
        .stdin = .ignore,
        .stdout = .pipe,
        .stderr = .ignore,
    });
    errdefer child.kill(io);

    // PROP_VALUE_MAX is 92, output is value + newline.
    // Currently API levels are two-digit numbers, but we want to make sure we never read a partial value.
    var stdout_buf: [92 + 1]u8 = undefined;
    var reader = child.stdout.?.readerStreaming(io, &.{});
    const n = try reader.interface.readSliceShort(&stdout_buf);
    const api_level = std.fmt.parseInt(u32, stdout_buf[0 .. n - 1], 10) catch |e| {
        std.log.err(
            "Could not parse API level, unexpected getprop output '{s}' ({s})",
            .{ stdout_buf[0 .. n - 1], @errorName(e) },
        );
        return error.ApiLevelQueryFailed;
    };

    switch (try child.wait(io)) {
        .exited => |code| if (code != 0) {
            std.log.err("getprop terminated abnormally with exit code: {d}", .{code});
            return error.ApiLevelQueryFailed;
        },
        .signal => |sig| {
            std.log.err("getprop terminated abnormally with signal: {t}", .{sig});
            return error.ApiLevelQueryFailed;
        },
        .stopped => |sig| {
            std.log.err("getprop stopped abnormally with signal: {t}", .{sig});
            return error.ApiLevelQueryFailed;
        },
        .unknown => {
            std.log.err("getprop terminated abnormally", .{});
            return error.ApiLevelQueryFailed;
        },
    }

    return api_level;
}