/*** legible.c ***
**** program copies input file spec to output file spec
**** replacing unusual non-visible chracters with newlines
**** DDBII 6/20/1988   ***/


#include <stdio.h>

#define TRUE  1
#define FALSE 0


main(argc,argv)

  int argc;          /* number of arguments */
  char *argv[];      /* string pointer to args */

  {
    int  bcnt, ccnt;       /* byte count and changed count */
    char infilename[40], outfilename[40], tmpstr[80], byte;
    FILE *infile, *outfile, *fopen();

    switch (argc)
      {
        case 3:      /* both input and output specs given */
          strcpy(infilename,argv[1]);
	  strcpy(outfilename,argv[2]);
	  break;
	case 2:      /* one spec given */
	  strcpy(outfilename,argv[1]);
	  strcpy(infilename,outfilename);
	  strcat(infilename,".old");
	  sprintf(tmpstr,"mv %s %s",outfilename,infilename);
	  system(tmpstr);       /* rename input file */
	  break;
	default:
	  printf ("name of input file: ");
	  scanf ("%s",infilename);
	  printf ("name of output file: ");
	  scanf ("%s",outfilename);
	  break;
      }

    if ((infile = fopen(infilename,"r")) == NULL)
      {
	printf ("?error with input spec...\n");
	exit(1);
      }

    if ((outfile = fopen(outfilename,"w")) == NULL)
      {
	printf ("?error with output spec...\n");
	exit(1);
      }

    ccnt = 0;
    bcnt = 0;
    while ((byte = getc(infile)) != EOF)
      {
	if (visible(byte))
	  putc(byte,outfile);
	else
	  {
	    putc('\n',outfile);
	    ccnt++;
	  }
	bcnt++;
      }

    fclose(infile);
    fclose(outfile);
    printf ("Copied %d, changed %d (bytes)\n",
				bcnt, ccnt);
  }


int visible(byte)	/* TRUE if normal char */
	char   byte;
    {
	if ((byte >= ' '  ||  byte == '\t'  ||  byte == '\n' 
		||  byte == '\f')  &&  byte <= '~')
	    return(TRUE);
	return(FALSE);
    }