CheckSumFolder is a command line tool written in Go that scans a directory recursively, computes checksums of every file and writes the results to an output text file. The tool can resume interrupted runs and also verify files against a previously generated list of hashes. By default SHA1 is used but the hash algorithm can be changed.

Building with NEON support requires CGO enabled and a working C compiler. The optional C implementations are only built on amd64 and arm64. Other architectures, including 32-bit ARM (armv7), always use the pure Go fallbacks.

CheckSumFolder -dir /path/to/dir [-list hashes.txt] [-hash sha256]

If -list is omitted the results are printed to the console. When a file is specified and it already contains results, existing entries are skipped so the operation can be resumed. Use -hash to select the hashing algorithm. Allowed values are md5, sha1, sha256, blake2b, blake3, xxhash, xxh3, xxh128, t1ha1, t1ha2, highway64, highway128, highway256, wyhash and rapidhash. When using a HighwayHash variant you can provide a custom key via the -hkey flag. The key must be 32 bytes encoded as hex or base64. If omitted the default key AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8= (base64) is used. HighwayHash assembly accelerates only x86 and ARM64 platforms.

• add option to save to jsol format Use -progress to periodically print how many files have been processed. When enabled, the total time taken is printed after completion. Use -json to write results in JSONL format where each line is a JSON object containing hash and path fields.

Example writing to a file:

CheckSumFolder -dir /path/to/dir -list hashes.txt -progress

CheckSumFolder -verify -dir /path/to/dir -list hashes.txt [-verbose]

The -dir flag specifies the folder containing the files to verify. Each line

in hashes.txt may contain absolute paths from a different system. During verification the program removes any common directory prefix from the paths in the list and joins the remainder with the directory provided via -dir. This allows verifying files across machines even when the root folders differ.

Use -verbose to print the status of every file. Without it, only mismatches are printed or a message that everything matches. Add -progress to show verification progress. When enabled, the total time taken is printed after completion. Verification runs in parallel across all CPU cores to speed up processing on large directory trees. Use -json when verifying to read the checksum list in JSONL format. When verifying with a HighwayHash algorithm pass the same key using -hkey. If the flag is omitted the same default key is assumed.

Example:

CheckSumFolder -verify -dir /path/to/dir -list hashes.txt -progress

ChecksumFolder detects available CPU features using the cpuid library. When SIMD instructions like SSE2 on x86 or ASIMD/NEON on ARM64 are present the program uses the accelerated sha256-simd implementation. blake2b-simd also provides optimized AVX2 and NEON assembly which is selected automatically when supported. HighwayHash also ships optimized assembly for x86 and ARM64 CPUs. The xxh3/xxh128 implementations detect AVX2 or NEON at runtime and use vectorized code when available. The t1ha routines include tuned implementations with optional AES and NEON support and fall back to portable code on other CPUs. No official armv7 assembly is provided. Wyhash and its successor rapidhash can use optional C wrappers compiled with -msse2 on Intel or -mfpu=neon on ARM64. These wrappers are only built on amd64 and arm64. When CGO is enabled and the CPU supports the required features, the program calls the C implementation for additional speed. Otherwise the pure Go fallback is used automatically. When NEON is detected the program also uses the official BLAKE3 C implementation via CGO for additional performance. The C implementation is only built on amd64 and arm64; other platforms use the pure Go version. A working C toolchain is required in this case. On older CPUs without these capabilities it transparently falls back to Go's standard implementations. This happens automatically at startup and works across different architectures.

This project is licensed under the MIT License.