Function dumpHexFallible [src]

Prints a hexadecimal view of the bytes, returning any error that occurs.

Prototype

pub fn dumpHexFallible(bw: *Writer, ttyconf: tty.Config, bytes: []const u8) !void

Parameters

bw: *Writerttyconf: tty.Configbytes: []const u8

Example

 test dumpHexFallible {
    const bytes: []const u8 = &.{ 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff, 0x01, 0x12, 0x13 };
    var aw: Writer.Allocating = .init(std.testing.allocator);
    defer aw.deinit();

    try dumpHexFallible(&aw.writer, .no_color, bytes);
    const expected = try std.fmt.allocPrint(std.testing.allocator,
        \\{x:0>[2]}  00 11 22 33 44 55 66 77  88 99 AA BB CC DD EE FF  .."3DUfw........
        \\{x:0>[2]}  01 12 13                                          ...
        \\
    , .{
        @intFromPtr(bytes.ptr),
        @intFromPtr(bytes.ptr) + 16,
        @sizeOf(usize) * 2,
    });
    defer std.testing.allocator.free(expected);
    try std.testing.expectEqualStrings(expected, aw.written());
}

Source

  pub fn dumpHexFallible(bw: *Writer, ttyconf: tty.Config, bytes: []const u8) !void {
    var chunks = mem.window(u8, bytes, 16, 16);
    while (chunks.next()) |window| {
        // 1. Print the address.
        const address = (@intFromPtr(bytes.ptr) + 0x10 * (std.math.divCeil(usize, chunks.index orelse bytes.len, 16) catch unreachable)) - 0x10;
        try ttyconf.setColor(bw, .dim);
        // We print the address in lowercase and the bytes in uppercase hexadecimal to distinguish them more.
        // Also, make sure all lines are aligned by padding the address.
        try bw.print("{x:0>[1]}  ", .{ address, @sizeOf(usize) * 2 });
        try ttyconf.setColor(bw, .reset);

        // 2. Print the bytes.
        for (window, 0..) |byte, index| {
            try bw.print("{X:0>2} ", .{byte});
            if (index == 7) try bw.writeByte(' ');
        }
        try bw.writeByte(' ');
        if (window.len < 16) {
            var missing_columns = (16 - window.len) * 3;
            if (window.len < 8) missing_columns += 1;
            try bw.splatByteAll(' ', missing_columns);
        }

        // 3. Print the characters.
        for (window) |byte| {
            if (std.ascii.isPrint(byte)) {
                try bw.writeByte(byte);
            } else {
                // Related: https://github.com/ziglang/zig/issues/7600
                if (ttyconf == .windows_api) {
                    try bw.writeByte('.');
                    continue;
                }

                // Let's print some common control codes as graphical Unicode symbols.
                // We don't want to do this for all control codes because most control codes apart from
                // the ones that Zig has escape sequences for are likely not very useful to print as symbols.
                switch (byte) {
                    '\n' => try bw.writeAll("␊"),
                    '\r' => try bw.writeAll("␍"),
                    '\t' => try bw.writeAll("␉"),
                    else => try bw.writeByte('.'),
                }
            }
        }
        try bw.writeByte('\n');
    }
}  