/* Split a large text file into a set of smaller files */

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

int  lump_size = 1000;
char *pattern;
char *in_file;
char *out_file = "split.";
char out_name[128];
int  out_count = 0;

void
doopts(argc,argv)
    int argc;
    char **argv;
   {/* Get the command line options */
    int i,got_out;

    got_out = 0;
    for(i=1;i<argc;i++)
       {if(argv[i][0] == '-')
           {
            switch(argv[i][1])
               {
                case 'C': case 'c':
                    out_count = atoi(&argv[i][2]);
                    break;
                case 'L': case 'l':
                    lump_size = atoi(&argv[i][2]);
                    break;
                case 'p': case 'P':
                    pattern = &argv[i][2];
                    break;
                default:
                    /* Tell the user the real set of options */
                    goto out_options;
                }
            }
          else if(in_file==NULL)
           {/* Data file name */
            in_file = argv[i];
            }
          else if(!got_out)
           {/* Data file name */
            out_file = argv[i];
            got_out = ~0;
            }
          else
           {
out_options:
            printf("Options are\n\n");
            printf("    -l<lump_length>\n");
            printf("    -p<text_pattern>\n");
            printf("    -c<initial_count>\n");
            printf("    <source_file>\n");
            printf("    [<out_file>]\n");
            exit(20);
            }
        }
    if(in_file==NULL)
        goto out_options;
    }

main(argc,argv)
    int argc;
    char **argv;
   {/* Split a large file into smaller files */
    FILE *in_fptr;
    FILE *out_fptr;
    int count;

    doopts(argc,argv);

    /* Open the input file */
    in_fptr = fopen(in_file,"r");
    if(in_fptr == NULL)
       {printf("Cannot open file \"%s\"\n",in_file);
        exit(20);
        }

    count = 0;
    while(!feof(in_fptr))
       {/* So we must start another file */
        sprintf(out_name,"%s%d",out_file,out_count++);
        out_fptr = fopen(out_name,"w");
        if(out_fptr == NULL)
           {printf("Cannot open file \"%s\"\n",out_name);
            exit(20);
            }
        if(pattern)
           {/* Matching a pattern, take the simplest approach */
            if(count)
                fputs(pattern,out_fptr);
            count = 0;
            while(!feof(in_fptr) && pattern[count]!='\0')
               {/* Check out this char this will mess up if we try 
                   to make it case insensitive */
                char next;
                next = fgetc(in_fptr);
                if(pattern[count] == next)
                    ++count;
                  else if (count)
                   {int i;
                    for(i=0;i<count;++i)
                        fputc(pattern[i],out_fptr);
                    count = 0;
                    fputc(next,out_fptr);
                    }
                  else
                   {fputc(next,out_fptr);
                    }
                }
            }
          else
           {/* Just counting out the bytes, should use fread() but 
               I cannot be bothered */
            count = 0;
            while(!feof(in_fptr) && count<lump_size)
               {fputc(fgetc(in_fptr),out_fptr);
                ++count;
                }
            }
        fclose(out_fptr);
        }
    fclose(in_fptr);
    }