lib/libstand/gets.c

   1 /*      $NetBSD: gets.c,v 1.6 1995/10/11 21:16:57 pk Exp $      */
   2 /* $DragonFly: src/lib/libstand/gets.c,v 1.2 2004/10/25 19:38:45 drhodus Exp $                                                  */
   3
   4 /*-
   5  * Copyright (c) 1993
   6  *      The Regents of the University of California.  All rights reserved.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  *
  32  *      @(#)gets.c      8.1 (Berkeley) 6/11/93
  33  */
  34
  35 #include "stand.h"
  36
  37 /* gets() with constrained input length */
  38
  39 void
  40 ngets(char *buf, int n)
  41 {
  42     int c;
  43     char *lp;
  44
  45     for (lp = buf;;)
  46         switch (c = getchar() & 0177) {
  47         case '\n':
  48         case '\r':
  49             *lp = '\0';
  50             putchar('\n');
  51             return;
  52         case '\b':
  53         case '\177':
  54             if (lp > buf) {
  55                 lp--;
  56                 putchar('\b');
  57                 putchar(' ');
  58                 putchar('\b');
  59             }
  60             break;
  61         case 'r'&037: {
  62             char *p;
  63
  64             putchar('\n');
  65             for (p = buf; p < lp; ++p)
  66                 putchar(*p);
  67             break;
  68         }
  69         case 'u'&037:
  70         case 'w'&037:
  71             lp = buf;
  72             putchar('\n');
  73             break;
  74         default:
  75             if ((n < 1) || ((lp - buf) < n)) {
  76                 *lp++ = c;
  77                 putchar(c);
  78             }
  79         }
  80     /*NOTREACHED*/
  81 }
  82
  83 int
  84 fgetstr(char *buf, int size, int fd)
  85 {
  86     char        c;
  87     int         err, len;
  88
  89     size--;     /* leave space for terminator */
  90     len = 0;
  91     while (size != 0) {
  92         err = read(fd, &c, sizeof(c));
  93         if (err < 0)            /* read error */
  94             return(-1);
  95         if (err == 0) {         /* EOF */
  96             if (len == 0)
  97                 return(-1);     /* nothing to read */
  98             break;
  99         }
 100         if ((c == '\r') ||      /* line terminators */
 101             (c == '\n'))
 102             break;
 103         *buf++ = c;             /* keep char */
 104         size--;
 105         len++;
 106     }
 107     *buf = 0;
 108     return(len);
 109 }
 110
 111 char *
 112 fgets(char *buf, int size, int fd)
 113 {
 114     char        c, *p;
 115     int         err, len;
 116
 117     p = buf;
 118     size--;     /* leave space for terminator */
 119     len = 0;
 120     while (size != 0) {
 121         err = read(fd, &c, sizeof(c));
 122         if (err < 0)            /* read error */
 123             return(NULL);
 124         if (err == 0) {         /* EOF */
 125             if (len == 0)
 126                 return(NULL);   /* nothing to read */
 127             break;
 128         }
 129         *p++ = c;               /* keep char */
 130         size--;
 131         len++;
 132         if ((c == '\r') ||      /* line terminators */
 133             (c == '\n'))
 134             break;
 135     }
 136     *p = 0;
 137     return(buf);
 138 }