Function hexToBytes [src]

Decodes the sequence of bytes represented by the specified string of hexadecimal characters. Returns a slice of the output buffer containing the decoded bytes.

Prototype

pub fn hexToBytes(out: []u8, input: []const u8) ![]u8

Parameters

out: []u8input: []const u8

Example

 test hexToBytes {
    var buf: [32]u8 = undefined;
    try expectFmt("90" ** 32, "{s}", .{fmtSliceHexUpper(try hexToBytes(&buf, "90" ** 32))});
    try expectFmt("ABCD", "{s}", .{fmtSliceHexUpper(try hexToBytes(&buf, "ABCD"))});
    try expectFmt("", "{s}", .{fmtSliceHexUpper(try hexToBytes(&buf, ""))});
    try std.testing.expectError(error.InvalidCharacter, hexToBytes(&buf, "012Z"));
    try std.testing.expectError(error.InvalidLength, hexToBytes(&buf, "AAA"));
    try std.testing.expectError(error.NoSpaceLeft, hexToBytes(buf[0..1], "ABAB"));
}

Source

  pub fn hexToBytes(out: []u8, input: []const u8) ![]u8 {
    // Expect 0 or n pairs of hexadecimal digits.
    if (input.len & 1 != 0)
        return error.InvalidLength;
    if (out.len * 2 < input.len)
        return error.NoSpaceLeft;

    var in_i: usize = 0;
    while (in_i < input.len) : (in_i += 2) {
        const hi = try charToDigit(input[in_i], 16);
        const lo = try charToDigit(input[in_i + 1], 16);
        out[in_i / 2] = (hi << 4) | lo;
    }

    return out[0 .. in_i / 2];
}  