xref: /dragonfly/stand/lib/gets.c (revision 655933d6)
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 }
139