D executable size experiment.

dzip.d

/++
 + Experiment 2017-02-28.
 + Author: Георгий Устинов
 + License: CC0.
 +
 + Executable size on Linux x86_64
 + LDC2 0.17.1 (DMD v2.068.2, LLVM 3.8.0)
 +
 +      ldc2 dzip.d ............... 26.6 KiB (27 232)
 +      ldc2 -release dzip.d ...... 26.5 KiB (27 176)
 +      ldc2 -Os dzip.d ........... 20.2 KiB (20 736)
 +      ldc2 -Oz dzip.d ........... 20.2 KiB (20 736)
 +      ldc2 -release -Os dzip.d .. 20.2 KiB (20 696)
 +      ldc2 -release -Oz dzip.d .. 20.2 KiB (20 696)
 +
 + But this is without `-static` flag.
 + So, if you run executable on the clean system.
 + sudo docker run -it -v /home/georgy/hostFolder/:/data  ubuntu
 + # cd /data/
 + # ./dzip test.txt test.zlib
 + ./dzip: error while loading shared libraries: libphobos2-ldc.so.68: cannot open shared object file: No such file or directory
 +
 + Сonclusion:
 + You can use zlib module to decompress resources like fonts, texts, etc.
 + But it makes sense only if your user already has phobos installed or
 + if you has *large* resource set, because statically linked executable
 + weight is at least 1.5-2 MiB (both DMD and LDC2).
 +
 + Also, currently, statically linked executables from LDC2 show the warnings,
 + that glibc still use some shared libraries.
 + Also, glibc has the big foot (~600 KiB, as I know).
 + http://www.etalabs.net/compare_libcs.html
 + TODO: Try to statically link with Musl inside Docker and then run on host system (Kubuntu).
 +/
module dzip;

import std.stdio : writeln;
import std.file;
import std.zlib;

void main(char[][] args) {
    if (args.length != 4) {
        writeln("Usage:\ndgzip -c input.txt ouput.zlib\ndgzip -d ouput.zlib input.txt");
    }

    auto input = cast(ubyte[]) read(args[2]);
    ubyte[] output;
    if (args[1] == "-c") {
        output = cast(ubyte[]) compress(input);
    } else if (args[1] == "-d") {
        output = cast(ubyte[]) uncompress(input);
    }
    write(args[3], output);
}