gxpack.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <dirent.h> 

#pragma pack(push, 1)

/* Library Header */
typedef struct {
    unsigned short  id;         /* Library header id (=0CA01H) */
    char  copyright[50];        /* Copyright notice            */
    unsigned short  version;    /* gxLib version               */
    char  label[40];            /* Library volume label        */
    unsigned short  entries;    /* Total image entries         */
    char  reserved[32];         /* Reserved for GX kernel      */
} GXLIBHEADER;

/* Library File Information */
typedef struct {
    char  pack;                  /* Packing type                */
    char  filename[13];          /* Image file name             */
    unsigned int    fileoffs;    /* File offset (absolute)      */
    unsigned int    filesize;    /* File size                   */
    unsigned short  date;        /* File date                   */
    unsigned short  time;        /* File time                   */
} GXFINFO;

#pragma pack(pop)

int fsize(FILE *fp) {
    int prev = ftell(fp);
    fseek(fp, 0L, SEEK_END);
    
    int sz = ftell(fp);
    fseek(fp, prev, SEEK_SET);
    
    return sz;
}

char reserved_blob[] = {0x58,0x19,0xFA,0x6C,0x15,0x2F,0x02,0x00,0x17,0x3A,0x17,0x3A,0x58,0x19,0x58,0x19,0x03,0x00,0xE0,0x24,0xA2,0x37,0x9B,0x1F,0x3B,0x6D,0x15,0x2F,0xA1,0x13,0x9B,0x1F};
char *copyright_text = "Copyright (c) Genus Microprogramming, Inc. 1988-94";

int main(int argc, char *argv[]) {
    if (argc != 2) {
        printf("Usage: gxpack <directory>\n\n");
        return 1;
    }
        
    DIR *dr = opendir(argv[1]);
    if (dr == NULL) { 
        printf("Could not open current directory" ); 
        return 1; 
    } 

    short filecount = 0;
    struct dirent *de;
    while ((de = readdir(dr)) != NULL) {
        char *name = de->d_name;
        if(name[0] == '.') {            
            continue;
        }
        
        printf("%s\n", name);
        filecount++;
    }
    
    
    GXFINFO *entries = malloc(filecount * sizeof(GXFINFO));
    memset(entries, 0, filecount * sizeof(GXFINFO));

    char buffer[1024*1024];

    int i = 0;    
    rewinddir(dr);
    
    int buffsize = 0;
    char fp[255];
    FILE *fe;
    while ((de = readdir(dr)) != NULL) {
        if(de->d_name[0] == '.') {
            continue;
        }
                
        // FILE NAME //
        char input[13];
        strlcpy(input, de->d_name, 13);
        
        char *name = strtok(input, ".");
        char *ext = strtok(NULL, ".");
        
        sprintf(entries[i].filename, "%-8s%c%s", name, '.', ext);
        
        char *s = entries[i].filename;
        do {
            *s = toupper(*s);
            s++;
        } while (*s);
        // FILE NAME //
        
        sprintf(fp, "%s/%s", argv[1], de->d_name);
        fe = fopen(fp, "rb");
        entries[i].filesize = fsize(fe);
        entries[i].fileoffs = sizeof(GXFINFO)*filecount + sizeof(GXLIBHEADER) + buffsize;
        
        fread(&buffer[buffsize], 1, entries[i].filesize, fe);
        fclose(fe);
        
        buffsize += entries[i].filesize;
    
        i++;
    }
    
    
    closedir(dr);
    
    // HEADER
    GXLIBHEADER header;
    
    header.id = 0xca01;
    memcpy(header.copyright, copyright_text, 50);
    header.version = 0x64;
    header.entries = filecount;
    memcpy(header.reserved, reserved_blob, 32);
    
    FILE *f = fopen("test.gxl", "wb");
    if (f == NULL) {
        printf("Could not open output file"); 
        return 1; 
    }
        
    fwrite(&header, sizeof(header), 1, f);
    fwrite(entries, sizeof(GXFINFO), filecount, f);
    fwrite(buffer, 1, buffsize, f);
    
    fclose(f);
}