ddh 1.3.0

ddh, DD's Hashing command utility

ddh is a simple hasher available cross-platform (Windows, macOS, Linux, BSDs) and comes with more features than built-in OS utilities.

Feature Comparison

Feature	ddh	GNU coreutils	OpenSSL	crc32(1)[^1]
Binary mode	✔️	✔️	✔️	✔️
Text mode	✔️	✔️
Check support	✔️	✔️[^2]	✔️	✔️
File support	✔️	✔️	✔️	✔️
Memory-mapped file support	✔️
Standard input (stdin) support	✔️	✔️	✔️
GNU style hashes	✔️	✔️	✔️[^4]
BSD style hashes	✔️	✔️	✔️
SRI style hashes	✔️	[^5]	[^5]

Algorithm Availability

Checksum or Hash	ddh	GNU coreutils	OpenSSL[^3]	crc32(1)[^1]
CRC-32	✔️			✔️
CRC-64-ISO	✔️
CRC-64-ECMA	✔️
MD5	✔️	✔️ (md5sum)	✔️
RIPEMD-160	✔️		✔️
SHA-1	✔️	✔️ (sha1sum)	✔️
SHA-2	✔️	✔️ (sha224sum, sha256sum, sha384sum, sha512sum)	✔️
SHA-3	✔️		✔️
SHAKE	✔️		✔️
BLAKE2b	✔️	✔️ (b2sum)	✔️
BLAKE2s	✔️		✔️
BLAKE3		✔️ (b3sum)

Usage

Format: ddh HASH [OPTIONS...] FILE[...]

With no arguments, the help page is shown.

For a list of options available, use the --help argument.

For a list of supported checksums and hashes, use the list command.

Example

$ ddh md5 LICENSE
1d267ceb3a8d8f75f1be3011ee4cbf53  LICENSE

Hash styles

Style	Example
GNU (default)	1d267ceb3a8d8f75f1be3011ee4cbf53 LICENSE
BSD (--tag)	MD5(LICENSE)= 1d267ceb3a8d8f75f1be3011ee4cbf53
SRI (--sri)	md5-HSZ86zqNj3XxvjAR7ky/Uw==

Standard Input (stdin)

To use the standard input (stdin) method, either:

• Omit the third parameter (e.g., ddh md5);
• Or use the - character (e.g., ddh md5 -).

File Pattern Globbing (* vs. '*')

This utility supports file globbing out of the box using std.file.dirEntries.

However, while useful on Windows, most UNIX-like terminals support in-shell globbing. This may behave differently than the dirEntries function.

To force the usage of the embedded globbing mechanism, you may want to use '*' or \*. To disable it, use the -- parameter.

The globbing pattern is further explained on dlang.org.

The default parameters used in dirEntries are:

• SpanMode: shallow (same-level directory);
• And followSymlink: true (follows soft symbolic links).

NOTE: The embedded globbing system includes hidden files.

EXAMPLE: A pattern such as src/*.{d,dd}:

• Matches src/example.d, src/.dd, and src/file.dd;
• But doesn't match example.d, src/.ddd, and src/.e;
• Basically all files ending with .d and .dd in the src directory, following symlinks.

Memory-mapped Files

The mmfile mode's performance may vary on systems. Typically, file mode is faster on Windows, and mmfile mode is faster on Linux systems.

The default is file.

Checking against a list

To check hashes in a list, like for example:

34f53abbdbc66ebdb969c5a77f0f8902  .gitignore
301dff35a1c11b231b67aaaed0e7be46  ddh
38605d99f2cd043879c401ff1fe292cf  ddh-test-library.exe
9a2fdb96ff77f4d71510b38c2f278ff6  ddh.exe

Simply use the -c option: ddh md5 -c LIST.

Only the GNU and BSD (tag) styles can be used in file checks.

Compiling

Compiling requires a recent D compiler and DUB.

To compile a debug build with the default compiler:

dub build

Release recommendation with the LDC compiler:

dub build -b release-nobounds --compiler=ldc2