ddh 1.0.0

ddh, Generic hasher

ddh is a generic hasher using the D standard library for the most part to perform hashing and compute checksums.

Why? I wanted:

• Something quick and easy to verify the integrety of downloaded content;
• Something simple with only the most popular hashing algorithms used;
• A cross-platform tool, notably Windows®️ and Linux®️;
• A memory-mapped option (--mmfile);
• The same features accross different algorithms;
• And decently fast.

Algorithm Availability

Checksum or Hash	ddh	GNU coreutils	openssl [1]	crc32(1) [2]
BSD sum		✔️ (sum)
System V sum		✔️ (sum -s)
Ethernet CRC		✔️ (cksum)
MDC-2-128			✔️
CRC-32	✔️			✔️
CRC-64-ISO	✔️
CRC-64-ECMA	✔️
MD4			✔️
MD5	✔️	✔️ (md5sum)	✔️
SM3			✔️
RIPEMD-160	✔️		✔️
SHA-1	✔️	✔️ (sha1sum)	✔️
SHA-2	✔️	✔️ [3]	✔️
SHA-3	✔️		✔️
SHAKE	✔️		✔️
BLAKE2		✔️ (b2sum)	✔️
Whirlpool			✔️

• [1] See dgst command
• [2] From the Perl Archive::ZIP package
• [3] sha224sum, sha256sum, sha384sum, sha512sum

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 support	✔️	✔️	✔️

• [1] From the Perl Archive::ZIP package
• [2] All but cksum and sum

Usage

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

Standard Input (stdin)

The program, if lacking a third parameter or if a - parameter has been detected, will enter in the stdin input mode. Please note that the --mmfile option has no effect on this operating mode.

Standard pipe operations are supported.

To send a EOF signal:

• On UNIX-like systems:
• CTRL+D must be pressed twice on the same line or;
• CTRL+D must be pressed once on a new line.
• On Windows systems:
• CTRL+Z on a new line followed with RETURN (Enter key).
  • This unfortunately sends a newline.
  • BUG: Must be done twice due to cmd internal mechanics. Piping recommended.

Globbing (* vs. '*')

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

However, most UNIX-like terminals support globbing out of the box and may behave differently than the previously mentionned function. To use the embedded globbing mechanism, you may want to use '*' or \*. To disable embedded globbing, use the -- parameter.

The globbing pattern is further explained at dlang.org.

The default parameters used in dirEntries are SpanMode.shallow for its spanmode (same-level directory), and true for following symobolic links.

Do take note that the embedded globbing subsystem includes hidden files.

For example: src/*.{d,dd} will match all files ending with .d and .dd in the src directory, and will follow symbolic links.

Memory-mapped Files

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

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