extract buriko arc20 archives (raw data only)

unarc.cpp

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <vector>

void fread_or_die(void * a, size_t b, size_t c, FILE * d)
{
    size_t got = fread(a, b, c, d);
    if(feof(d)) {puts("feof"); exit(0);}
    if(ferror(d)) {puts("ferror"); exit(0);}
    if(got != c) {exit(0);}
}

struct filedata
{
    char filename[96];
    uint32_t offset;
    uint32_t size;
    char padding[24];
};

int main(int argc, char ** argv)
{
    if(argc < 2) return puts("Usage: unarc file.arc"), 0;
    
    auto f = fopen(argv[1], "rb");
    
    char magic[12];
    fread_or_die(magic, 12, 1, f);
    if(strncmp(magic, "BURIKO ARC20", 12) != 0) return puts("File is not supported or is invalid."), 0;
    
    uint32_t numfiles;
    fread_or_die(&numfiles, 4, 1, f);
    
    std::vector<filedata> files;
    for(uint64_t i = 0; i < numfiles; i++)
    {
        filedata newfile;
        fread_or_die(&newfile.filename, 1, 96, f);
        fread_or_die(&newfile.offset, 4, 1, f);
        fread_or_die(&newfile.size, 4, 1, f);
        fread_or_die(&newfile.padding, 1, 24, f);
        files.push_back(newfile);
    }
    
    long int start = ftell(f);
    for(auto file : files)
    {
        unsigned char * data = (unsigned char*)malloc(file.size);
        
        fseek(f, start+file.offset, SEEK_SET);
        fread_or_die(data, 1, file.size, f);
        
        auto out = fopen(file.filename, "wb");
        fwrite(data, 1, file.size, out);
        fclose(out);
        
        free(data);
    }
}