usr/src/boot/lib/libstand/gets.c

   1 /*      $NetBSD: gets.c,v 1.6 1995/10/11 21:16:57 pk 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  * 4. Neither the name of the University nor the names of its contributors
  16  *    may be used to endorse or promote products derived from this software
  17  *    without specific prior written permission.
  18  *
  19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  29  * SUCH DAMAGE.
  30  *
  31  *      @(#)gets.c      8.1 (Berkeley) 6/11/93
  32  */
  33
  34 #include <sys/cdefs.h>
  35 __FBSDID("$FreeBSD$");
  36
  37 #include "stand.h"
  38
  39 /* gets() with constrained input length */
  40
  41 void
  42 ngets(char *buf, int n)
  43 {
  44     int c;
  45     char *lp;
  46
  47     for (lp = buf;;)
  48         switch (c = getchar() & 0177) {
  49         case '\n':
  50         case '\r':
  51             *lp = '\0';
  52             putchar('\n');
  53             return;
  54         case '\b':
  55         case '\177':
  56             if (lp > buf) {
  57                 lp--;
  58                 putchar('\b');
  59                 putchar(' ');
  60                 putchar('\b');
  61             }
  62             break;
  63         case 'r'&037: {
  64             char *p;
  65
  66             putchar('\n');
  67             for (p = buf; p < lp; ++p)
  68                 putchar(*p);
  69             break;
  70         }
  71         case 'u'&037:
  72         case 'w'&037:
  73             lp = buf;
  74             putchar('\n');
  75             break;
  76         default:
  77             if ((n < 1) || ((lp - buf) < n - 1)) {
  78                 *lp++ = c;
  79                 putchar(c);
  80             }
  81         }
  82     /*NOTREACHED*/
  83 }
  84
  85 int
  86 fgetstr(char *buf, int size, int fd)
  87 {
  88     char        c;
  89     int         err, len;
  90
  91     size--;     /* leave space for terminator */
  92     len = 0;
  93     while (size != 0) {
  94         err = read(fd, &c, sizeof(c));
  95         if (err < 0)            /* read error */
  96             return(-1);
  97         if (err == 0) {         /* EOF */
  98             if (len == 0)
  99                 return(-1);     /* nothing to read */
 100             break;
 101         }
 102         if ((c == '\r') ||      /* line terminators */
 103             (c == '\n'))
 104             break;
 105         *buf++ = c;             /* keep char */
 106         size--;
 107         len++;
 108     }
 109     *buf = 0;
 110     return(len);
 111 }
 112