/*
   =============================================================================
	getline.c -- get a line from stdin
	Version 1 -- 1988-05-03 -- D.N. Lynx Crowe
	Does line editing.  Acts like gets().
   =============================================================================
*/

#include "stdio.h"
#include "ascii.h"
#include "stddefs.h"

char *
getline(buf, nb)
char *buf;	/* buffer pointer */
int nb;		/* buffer limit */
{
	register char *bp;
	register int c;
	register int bc;

	bc = 0;		/* number of characters currently in buffer */
	bp = buf;	/* current buffer pointer */
	*bp = '\0';	/* initial null into buffer */

	while (bc < nb) {		/* read up to limit */

		c = getchar();

		switch (c) {

		case A_BS:
		case A_DEL:

			if (bc EQ 0) {

				putchar(A_BEL);	/* complain -- nothing there */
				break;

			} else {

				bc--;		/* decrement byte count */
				bp--;		/* back-up the pointer */
				*bp = '\0';	/* terminate the string */

				putchar(A_BS);	/* erase character from screen */
				putchar(' ');
				putchar(A_BS);

				break;
			}

		case A_CR:
		case A_LF:

			*bp = '\0';		/* terminate line with null */
			return(buf);		/* return -- CR or LF hit */

/*  */

		case CTL('X'):

			*buf = '\0';		/* clear the buffer */

			while (bc--) {

				putchar(A_BS);
				putchar(' ');
				putchar(A_BS);
			}

			bc = 0;		/* reset byte count */
			bp = buf;	/* reset buffer pointer */
			break;

		case EOF:

			return(NULL);

		default:

			*bp++ = (char)c;	/* put character in buffer */
			*bp = '\0';		/* terminate line with null */
			putchar(c);		/* echo the character */
			bc++;			/* update character count */
		}
	}

	buf[nb - 1] = '\0';	/* terminate buffer */
	return(buf);		/* buffer full error */
}