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

#include <string.h>
#define FALSE 0
#define TRUE !FALSE

int fsize(char* file){
     FILE* pFile = fopen(file,"rb");
     int size;
     fseek (pFile, 0, SEEK_END);
     size=ftell (pFile);
     fclose(pFile);
     return size;
}

void Join(int argc, char* argv[]){
     
     char out_text[256] = {0};
     char* buffer;
     int size;
     FILE* pFile,* out;
     int i = 0;
     printf("nome de sada: ");
     scanf("%s", out_text);
     out = fopen(out_text,"wb");
     size = fsize(argv[1]);
     buffer = malloc(size);
     for (i = 1; i < argc; i++){
         printf("juntando parte %d\n",i);
         size = fsize(argv[i]);
         pFile = fopen(argv[i],"rb");
         fread(buffer, size, 1, pFile);
         fclose(pFile);
         fwrite(buffer,size, 1, out);
     }
     fclose(out);
}
     

void Split(char* file){       
     FILE* pFile,* out;
     char out_text[256] = {0};
     char* chunk;
     int chunk_size;
     int i,c;
     int size;
     int total = 0;
     int left;

     size = fsize(file);
     pFile = fopen(file,"rb");
     printf("deseja dividir o arquivo em quantas partes? ");
     scanf("%d",&c);
     chunk_size = size / c;
     chunk = malloc(chunk_size);
     
     for (i = 0; i < c; i++){
         sprintf(out_text,"%s.%03d",file,c);
         printf("writing %s\n",out_text);
         fseek(pFile, i * chunk_size, SEEK_SET);
         total += chunk_size;
         fread(chunk, chunk_size, 1, pFile);
         fopen(out_text,"wb");
         fwrite(chunk,chunk_size, 1, out);
         fclose(out);
     }
     if (total < size){
         sprintf(out_text,"%s.%03d",file,c);
         printf("writing %s\n",out_text);
         fseek(pFile, i * chunk_size, SEEK_SET);
         left = size - total;
         fread(chunk, left, 1, pFile);
         fopen(out_text,"wb");
         fwrite(chunk,left, 1, out);
         fclose(out);
     }
     fclose(pFile);
     
}

int main(int argc, char *argv[])
{
  int i = 0;

  int split = FALSE;
  if (!strcmp(argv[1],"-s")){
         split = TRUE;
  }
  if (split)
     Split(argv[2]);
  else 
     Join(argc,argv);


  

  return 0;
}