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

int split(const char *filename, const char *tdrive, const char *tdir, const char *tname, size_t blocksize) {
        void *buffer = malloc(blocksize);
        if(buffer==NULL) {
                fprintf(stderr, "Could not allocate room for buffer (%d bytes)\n",blocksize);
                return 2;
        }

        FILE *ifp=fopen(filename,"rb");
        if(ifp==NULL) {
                perror("Could not open input file");
                return 3;
        }

        int count=0;
        for(;;) {
                char templatename[_MAX_PATH];
                char ext[_MAX_EXT];
                sprintf(ext,".%03d",count++);
                _makepath(templatename,tdrive,tdir,tname,ext);
                FILE *ofp=fopen(templatename,"wb");
                if(ofp==NULL) {
                        perror("Could not create output file");
                        return 4;
                }
                size_t bytesRead = fread(buffer,1,blocksize,ifp);
                size_t bytesWritten = fwrite(buffer,1,bytesRead,ofp);
                if(bytesWritten<bytesRead) {
                        perror("Could not write");
                        return 5;
                }
                if(fclose(ofp)!=0) {
                        perror("Could not close output file");
                        return 6;
                }
                if(bytesRead==0) {
                        remove(templatename);
                        break;
                }
                printf("%s %ld\n",templatename,(long)bytesWritten);
                
        }
        fclose(ifp);
        return 0;
}

int main(int argc, char *argv[]) {
        if(argc!=4 ||
           stricmp(argv[1],"/?")==0 ||
           stricmp(argv[1],"/h")==0 ||
           stricmp(argv[1],"-usage")==0)
        {
                printf("Usage: split <filename> <template> <splitsize>\n");
                printf("  <filename>    file to split\n");
                printf("  <template>    output filename template\n");
                printf("  <splitsize>   size of each block\n");
                printf("Example:\n");
                printf("  split myfile.big myfile.* 10000\n");
                return -1;
        }

        char tdrive[_MAX_DRIVE],tdir[_MAX_DIR],tname[_MAX_FNAME],text[_MAX_EXT];
        _splitpath(argv[2],tdrive,tdir,tname,text);
        long blocksize=atol(argv[3]);
        if(blocksize<0 || blocksize>65535L) {
                fprintf(stderr,"Blocksize must be within 1..65535\n");
                return 1;
        }
        return split(argv[1],tdrive,tdir,tname,(size_t)blocksize);
}