/* Adding machine */

/*
  Author:
   Frank da Cruz, Columbia University, August 1988
   fdc@columbia.edu
   Please send any changes back to the author.

  To build
   make "CFLAGS=xxx" add
   where xxx is:
     POSIX for POSIX (tcsetattr())
     ATTSV for AT&T System V (ioctl())
   if CFLAGS omitted, BSD is used (stty())

  Copyright (C) 1988-2002,
  Trustees of Columbia University in the City of New York.
*/
#include <stdio.h>
#include <ctype.h>

#ifdef POSIX
#include <termios.h>
static struct termios ccold, ccraw;
#else
#ifdef ATTSV
#include <termio.h>
static struct termio ccold, ccraw;
#else
#include <sgtty.h>
static struct sgttyb ccold, ccraw;
#endif /* ATTSV */
#endif /* POSIX */

float a, s;
int i, k, n, tt, in_num, got_num, in_comment;
char buf[100], c;
char sav[100] = { '\0' };
char comment[100], *cp;
char *hlp[] = {
" ",
"Adding machine.  Type numbers to be added, may include decimal point.",
"Enter number with carriage return.  You can edit numbers with Delete",
"or Ctrl-U.  You can also enter the following single-character commands,",
"which act immediately (no CR):",
" ",
" q - quit (and print, total if any)",
" c - clear",
" r - repeat previous entry",
" s - print subtotal (don't clear total)",
" a - print average (don't clear)",
" t - print total (and clear)",
" ",
"And, if you have a column of numbers in a file, you can 'add < filename'.",
""
};

xx(c) char c; {
    *cp++ = c;
    if (tt) putchar(c);
}

main () {

    tt = isatty(0);			/* Input from real terminal? */

    if (tt) { /* If real terminal put in rawmode for no echo */
#ifdef POSIX				/* The POSIX way... */
        tcgetattr(0,&ccold);
	ccraw = ccold;
	ccraw.c_lflag &= ~(ISIG|ICANON|ECHO);
        tcsetattr(0,TCSADRAIN,&ccraw);
#else
#ifdef ATTSV
        tcgetattr(0,&cold);		/* The System V way... */
	ccraw = ccold;
	ccraw.c_lflag &= ~(ISIG|ICANON|ECHO);
	ioctl(0,TCSATAW,&ccraw);
#else
	gtty(0,&ccold);			/* The V7 / BSD way... */
	ccraw = ccold;
	ccraw.sg_flags |= (RAW);
	ccraw.sg_flags &= ~(ECHO|CRMOD);
	stty(0,&ccraw);
#endif /* ATTSV */
#endif /* POSIX */
	fprintf(stderr,"add...\r\n? for help\r\n"); /* Greet */
    }
    i = 0;				/* i is number buffer pointer */
    in_comment = 0;			/* in comment */
    in_num = 0;				/* in number */
    got_num = 0;			/* got number */
    cp = comment;			/* comment buffer */
    *cp = '\0';				/* zero it */
    while (1) {
	c = getchar();			/* Get a char */
	if (c == EOF) doexit(0);
	c &= 0177;
	switch (c) {
	  case '?':			/* Give help */
	    if (in_comment) xx(c);
	    else if (tt) {
		for ( k = 0; *hlp[k] ; k++ )
		  fprintf(stderr, "%s\r\n", hlp[k]);
		fprintf(stderr,"%s",buf);
	    }
	    break;
          case 'a':			/* Average */
          case 'A':
	    if (in_comment) xx(c);
	    else if (in_num == 1) {
		fprintf(stderr,"\07");
		break;
	    }
            else if (n == 0) fprintf(stderr,"(nothing to average)\r\n");
	    else
	      fprintf(stderr,"%10.2f = average (for %d)\r\n",(s / (float)n),n);
	    break;
	  case 'c':			/* Clear */
	  case 'C':
	    if (in_comment) xx(c);
	    else if (in_num == 1) {
		fprintf(stderr,"\07");
		break;
	    } else {
		s = 0.0;
		n = 0;
		fprintf(stderr,"    (clear)\r\n");
	    }
	    sav[0] = '\0';
	    break;
	  case 't':			/* Total & clear */
	  case 'T':
	    if (in_comment) xx(c);
	    else if (in_num == 1) {
		fprintf(stderr,"\07");
		break;
	    } else {
		fprintf(stderr,"%10.2f = total (for %d)\r\n",s,n);
		fprintf(stderr,"    (clear)\r\n");
		s = 0.0, n = 0;
	    }
	    sav[0] = '\0';
	    break;
	  case 's':			/* Subtotal */
	  case 'S':
	    if (in_comment) xx(c);
	    else if (in_num == 1) {
		fprintf(stderr,"\07");
		break;
	    } else fprintf(stderr,"%10.2f = subtotal (for %d)\r\n",s,n);
	    break;
	  case 'r':			/* Re-enter previous number */
	  case 'R':
	    if (in_comment) xx(c);
	    else if (in_num == 1) {
		fprintf(stderr,"\07");
		break;
	    }
	    strcpy(buf,sav);
	    printf(buf);
	    i = strlen(buf);
	    sav[0] = '\0';
	    break;
	  case 'q':			/* Quit */
	  case 'Q':
	    if (in_comment) {
		xx(c);
	    } else if (in_num == 1) {
		fprintf(stderr,"\07");
		break;
	    } else doexit(0);
	    break;
          case 127:			/* Delete, backspace */
          case '\010':			/* Erase prev character */
	    if (i > 0) {
		i--;
		fprintf(stderr,"\010 \010");
	    }
	    else fprintf(stderr,"\07");
	    break;
          case '\025':			/* Ctrl-U or Ctrl-W */
          case '\027':			/* Erase current number */
            i = 0;
	    buf[0] = '\0';
	    fprintf(stderr,"\r                \r");
            break;
          case '\r':			/* Enter the number */
          case '\n':
	    buf[i] = '\0';
	    if (tt) fprintf(stderr,"\r                \r");
	    if ((sscanf(buf, "%f", &a) != 1) && (i > 0)) {
	      fprintf(stderr,"%s - bad number\r\n",buf);
	    } else if (i > 0) {
	      s += a, n++;
	      if (tt) fprintf(stderr,"%10.2f %s\r\n",a,comment);
	      sprintf(sav,"%10.2f",a);
	      a = 0;
	    }
	    i = 0;
	    in_num = 0;
	    got_num = 0;
	    buf[0] = '\0';
	    in_comment = 0;
	    cp = comment;
	    *cp = '\0';
	    break;
      case ' ':				/* Blanks */
	    if (in_num) {
		in_num = 0;
		got_num = 1;
		in_comment = 1;
		xx(c);
	    } else if (in_comment) xx(c);
	    break;
      case '0':				/* A digit, or period, or minus */
      case '1':
      case '2':
      case '3':
      case '4':
      case '5':
      case '6':
      case '7':
      case '8':
      case '9':
      case '.':
      case '-':
	if (in_comment) xx(c);
	else {
	    in_num = 1;
	    if (tt) fputc(c,stderr);
	    buf[i++] = c;
	}
	break;
      default:				/* Beep on anything else */
	if (in_comment) xx(c);
	else fprintf(stderr,"\07");
	break;
        }
    }
}

doexit(p) int p; {			/* Restore tty on exit */
    if (s != 0.0)
      fprintf(stderr,"%10.2f = total (for %d)\r\n",s,n);
    if (tt)
#ifdef POSIX
      tcsetattr(0,TCSADRAIN,&ccold);
#else
#ifdef ATTSV
    ioctl(0,TCSETAW,&ccold);
#else
      stty(0,&ccold);
#endif /* ATTSV */
#endif /* POSIX */
    exit(p);
}