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

/*
    RMCR : routine to remove carriage return (CR = \r) characters from files.
           ("\r" shows up as "^M" in the editors.)

    Format:
           $ rmcr [-v] [ input file [ output file ] ]

    If no files are specified, stdin and stdout are used.  If only one file is
    named, it is assumed to be the input file.  Wild cards are not allowed.

*/

/*  Modification History:
  
    17 june 1992: creation (a.c.raugh)
    21 July 1992: added file error handling (acr)
    27 sept 1993: modified messages (acr)
    21 nove 1994: added "silent" mode (acr)
    21 July 1995: replaced -s with -v and reversed default behavior (acr)
*/

main(argc,argv)
int argc;
char *argv[];
{
    extern int errno;  /* system error code  */

    FILE *infile;   /* input file name   */
    FILE *outfile;  /* output file name  */

    int c;       /* input character      */
    int rcount;  /* record count         */
    int maxlen;  /* maximum line length  */
    int ccount;  /* line character count */
    int i;       /* loop/subscript       */
    int verbose; /* flag value           */

/*  Open files as needed (default to standard input and output);
*/
    
    if (argc > 4)
      { fprintf (stderr,"Usage: rmcr [-s] [input [output] ]\n");
        exit(0);
      }

    infile = outfile = NULL;
    verbose = 0;

    for (i=1; i<argc; ++i)
      { if (strcmp(argv[i],"-v")==0)
          { verbose = 1; }
        else if (infile == NULL)
          { if ((infile = fopen(argv[i],"r")) == NULL)
              { fprintf(stderr,"rmcr: Cannot open %s for reading (%s).\n",
                                argv[i],strerror(errno));
                exit(1);
              }
          }
        else if (outfile == NULL)
          { if ((outfile = fopen(argv[i],"w")) == NULL)
              { fprintf(stderr,"rmcr: Cannot open %s for writing (%s).\n",
                                argv[i],strerror(errno));
                exit(2);
              }
          }
      }

    infile  = ( infile==NULL)? stdin  :  infile;
    outfile = (outfile==NULL)? stdout : outfile;


/*  Loop through characters in this file.  Note that all carriage returns
    (\r) are removed regardless of whether or not they are followed by a
    linefeed (\n):
*/
    rcount = maxlen = ccount = 0;
    while ((c=getc(infile)) != EOF)
      {                              /* loop through characters */
	if (c != '\r') 
       	  { putc(c,outfile);
            ++ccount;
            if (c == '\n')
              { ++rcount;
                maxlen = (ccount > maxlen) ? ccount : maxlen;
                ccount = 0;
              }
          }

      }                              /* loop through characters */

/*  Report results to standard error: 
*/
    if (verbose)
      { fprintf (stderr,
             "\nrmcr: %d records written; longest record %d characters\n\n",
	     rcount,maxlen);
      }

/*  Close files:
*/
    fclose(infile);
    fclose(outfile);
    return 0;
}