amalthea ~main

The Amalthea Library is free software. This library is distributed in the hope that it will be useful, but without any warranty; without even the implied warranty of merchantability or fitness for a particular purpose.

Official repository: https://codeberg.org/os-18/amalthea

Mirror: https://gitlab.com/os-18/amalthea

Amalthea

Amalthea is a small, general-purpose, Linux-specific library for the D programming language. It provides several useful functions.

Library documentation: https://os-18.codeberg.page/amalthea/

Features

The Amalthea library has been under development as a standalone project since 2018. The project's goal is simple: over time, I have incrementally implemented features that I found missing in D's standard library, driven by the needs of my own projects. For various reasons, it is Linux-oriented; it has not been tested on other operating systems. Below are the modules I consider most useful.

amalthea.fs

Among the especially useful features, this module provides efficient implementations of read()/write()/copy()/copyRecurse(). It includes hardlink() for creating links to files, a set of functions for working with extended file attributes (xattr), truncate() for changing file size, a custom directory reading mechanism, and much more that improves file handling on Linux.

amalthea.sys

Among other things, this module provides functions for creating named pipes, resolving user and group names from IDs and vice versa, mounting and unmounting functions, and facilities for file/anonymous memory mappings. It implements UNIX signal handling. Functionality for working with loop devices is also provided.

amalthea.decimal

This module offers a straightforward implementation of fixed-point decimal numbers (the Decimal struct) built on top of BigInt from Phobos. A full set of basic arithmetic operations is implemented, including exponentiation and logarithms.

amalthea.dataprocessing

Contains several simple utilities for command-line argument handling, a JSON serializer for structs, and a deserializer from JSON back to structs. The copyArray() function is provided for copying arrays with const-correctness and proper handling of structs that may have copy constructors (the built-in dup does not always work correctly). Occasionally one needs an associative array with predictable element order; to satisfy that requirement, an OrderedMap struct is implemented.

amalthea.fileformats

This module provides functions for file format recognition based on both file signatures and extensions. Development of this module began when it became clear that the MIME system on Linux is not reliable enough — it fails to recognize formats such as TS (stream media container), DAV (CCTV video recording), several Microsoft-specific formats, some MATLAB formats, go.mod (Go module descriptor), PKT (Cisco Packet Tracer format), etc. For this module to work, several hundred format descriptions are stored in a separate file, fileformats.json, which is installed into /etc/amalthea-$DC/ (where $DC is the D compiler being used). The module also supports traditional MIME-based file format detection.

Ready-made packages

See: Download Page of OS-18

The page contains information on how to install several packages, including Amalthea.

Build from source

Preparing

You need to have at least one of the following compilers installed:

• Digital Mars D Compiler
• LLVM D Compiler
• GNU D Compiler

The library also depends on libgio-2.0 and libglib-2.0. These libraries are most likely already installed on your system.

Compilation and installation

To build static and dynamic libraries using the ldc2 compiler (default):

make

Installation (root privileges may be required):

make install

After that, the library for ldc2 is ready for use.

The Makefile contains variables:

• DESTDIR specifies the root directory for installing (empty by default);
• PREFIX specifies the base directory, such as usr/local or usr.

The installation directory is defined as $(DESTDIR)/$(PREFIX) in the Makefile.

You can install the library files in any directory. For example, to install into $HOME/.local:

make install DESTDIR=$HOME PREFIX=.local

Uninstall:

make uninstall

If the project was installed in a non-default location, use the corresponding paths:

make uninstall DESTDIR=$HOME PREFIX=.local

Other compilers

The default compiler is ldc2. You can choose another compiler (for example, dmd):

make DC=dmd

Installing:

make install DC=dmd

Uninstalling:

make uninstall DC=dmd

Feedback

For questions, suggestions, comments, or bugs reports, contact:

[email protected]

Also use the repository service tools.