zig std.debug.dump_hex proof of error

main.zig

const std = @import("std");

pub fn main() !void {
    const bytes: []const u8 = &.{ 0x00, 0x11, 0x22, 0x33, 0x44, 0x55, 0x66, 0x77, 0x88, 0x99, 0xaa, 0xbb, 0xcc, 0xdd, 0xee, 0xff, 0x01, 0x12, 0x13 };
    std.debug.print("std.debug on {*}: \n", .{bytes.ptr});
    std.debug.dump_hex(bytes);
    std.debug.print("with fix on {*}: \n", .{bytes.ptr});
    try dump_hex_fix(bytes);
}

pub fn dump_hex_fix(bytes: []const u8) !void {
    const stderr = std.io.getStdErr();
    const ttyconf = std.io.tty.detectConfig(stderr);
    const writer = stderr.writer();
    var chunks = std.mem.window(u8, bytes, 16, 16);
    while (chunks.next()) |window| {
        // 1. Print the address.
        const address = (@intFromPtr(bytes.ptr) + 0x10 * (try std.math.divCeil(usize, chunks.index orelse bytes.len, 16))) - 0x10;
        try ttyconf.setColor(writer, .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 writer.print("{x:0>[1]}  ", .{ address, @sizeOf(usize) * 2 });
        try ttyconf.setColor(writer, .reset);

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

        // 3. Print the characters.
        for (window) |byte| {
            if (std.ascii.isPrint(byte)) {
                try writer.writeByte(byte);
            } else {
                // Related: https://github.com/ziglang/zig/issues/7600
                if (ttyconf == .windows_api) {
                    try writer.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 writer.writeAll("␊"),
                    '\r' => try writer.writeAll("␍"),
                    '\t' => try writer.writeAll("␉"),
                    else => try writer.writeByte('.'),
                }
            }
        }
        try writer.writeByte('\n');
    }
}

output.txt

std.debug on u8@d9f04c: 
0000000000d9f04c  00 11 22 33 44 55 66 77  88 99 AA BB CC DD EE FF  .."3DUfw........
0000000000d9f03c  01 12 13                                          ...
with fix on u8@d9f04c: 
0000000000d9f04c  00 11 22 33 44 55 66 77  88 99 AA BB CC DD EE FF  .."3DUfw........
0000000000d9f05c  01 12 13