⚠️ WARNING: This is slop. zz is a vibe-coded fork of dd written in Zig by Claude. It may eat your data, corrupt your filesystem, or summon demons. Use at your own risk. Do not use in production. Do not use near open flames.

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zz

A rewrite of dd in Zig, with tests ported from the coreutils dd test suite.

Build

zig build

Binary lands at zig-out/bin/zz.

Usage

Same operand syntax as dd:

zz if=input.bin of=output.bin bs=4096
echo "hello" | zz conv=ucase
zz if=/dev/urandom of=file.bin count=100 bs=1M

Supported operands: if=, of=, bs=, ibs=, obs=, cbs=, count=, skip=/iseek=, seek=/oseek=, conv=, iflag=, oflag=, status=

Tests

bash run_tests.sh

Ported from the coreutils dd test suite: bytes.sh, misc.sh, skip-seek.pl, skip-seek2.sh, reblock.sh, conv-case.sh, stderr.sh.

Results: 55 passed, 0 failed, 0 skipped

Real hardware results

Tested on a Raspberry Pi against a 58GB microSD card (/dev/mmcblk0).

Test	Result
MBR read (512 bytes, raw device)	✅ Valid 55 aa signature
1MB raw read vs dd	✅ Byte-identical
100MB sequential read	✅ Matches dd throughput (~87 MB/s)
/etc/passwd file copy	✅ Identical
Binary (/usr/bin/ls) copy	✅ Identical
Partial read (skip=2 count=4 bs=64)	✅ Identical output and stats
10MB partition image vs dd	✅ Same SHA256
Round-trip copy at bs=4096	✅ 2560+0 records, identical