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gets.c revision 1.1 
      1 /*	$NetBSD: gets.c,v 1.1 2001/06/14 12:57:14 fredette Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  * 3. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)gets.c	8.1 (Berkeley) 6/11/93
     36  */
     37 
     38 #include "stand.h"
     39 
     40 /*
     41  * This implementation assumes that getchar() does echo, because
     42  * on some machines, it is hard to keep echo from being done.
     43  * Those that need it can do echo in their getchar() function.
     44  *
     45  * Yes, the code below will echo CR, DEL, and other control chars,
     46  * but sending CR or DEL here is harmless.  All the other editing
     47  * characters will be followed by a newline, so it doesn't matter.
     48  * (Most terminals will not show them anyway.)
     49  */
     50 
     51 void
     52 gets(buf)
     53 	char *buf;
     54 {
     55 	register int c;
     56 	register char *lp;
     57 
     58 top:
     59 	lp = buf;
     60 
     61 	for (;;) {
     62 		c = getchar() & 0177;
     63 
     64 #ifdef	GETS_MUST_ECHO	/* Preserved in case someone wants it... */
     65 		putchar(c);
     66 #endif
     67 
     68 		switch (c) {
     69 
     70 		default:
     71 			*lp++ = c;
     72 			continue;
     73 
     74 		case '\177':
     75 			putchar('\b');
     76 			/* fall through */
     77 		case '\b':
     78 			putchar(' ');
     79 			putchar('\b');
     80 			/* fall through */
     81 		case '#':
     82 			if (lp > buf)
     83 				lp--;
     84 			continue;
     85 
     86 #ifdef	GETS_REPRINT
     87 		/*
     88 		 * This is not very useful in a boot program.
     89 		 * (It costs you 52 bytes on m68k, gcc -O3).
     90 		 */
     91 		case 'r'&037: {
     92 			register char *p;
     93 			putchar('\n');
     94 			for (p = buf; p < lp; ++p)
     95 				putchar(*p);
     96 			continue;
     97 		}
     98 #endif
     99 
    100 		case '@':
    101 		case 'u'&037:
    102 		case 'w'&037:
    103 			putchar('\n');
    104 			goto top;
    105 
    106 		case '\r':
    107 			putchar('\n');
    108 			/* fall through */
    109 		case '\n':
    110 			*lp = '\0';
    111 			return;
    112 
    113 		} /* switch */
    114 	}
    115 	/*NOTREACHED*/
    116 }
    117