1 /*
2  * Copyright (c) 1997 - 2000 Kungliga Tekniska H�gskolan
3  * (Royal Institute of Technology, Stockholm, Sweden).
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  *
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  *
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  *
17  * 3. Neither the name of the Institute nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  */
33 
34 #include "login_locl.h"
35 
36 RCSID("$Id: read_string.c 18156 2006-09-22 15:42:39Z lha $");
37 
38 static sig_atomic_t intr_flag;
39 
40 static void
41 intr(int sig)
42 {
43     intr_flag++;
44 }
45 
46 #ifndef NSIG
47 #define NSIG 47
48 #endif
49 
50 int
51 read_string(const char *prompt, char *buf, size_t len, int echo)
52 {
53     struct sigaction sigs[NSIG];
54     int oksigs[NSIG];
55     struct sigaction sa;
56     FILE *tty;
57     int ret = 0;
58     int of = 0;
59     int i;
60     int c;
61     char *p;
62 
63     struct termios t_new, t_old;
64 
65     memset(&oksigs, 0, sizeof(oksigs));
66 
67     memset(&sa, 0, sizeof(sa));
68     sa.sa_handler = intr;
69     sigemptyset(&sa.sa_mask);
70     sa.sa_flags = 0;
71     for(i = 1; i < sizeof(sigs) / sizeof(sigs[0]); i++)
72 	if (i != SIGALRM)
73 	    if (sigaction(i, &sa, &sigs[i]) == 0)
74 		oksigs[i] = 1;
75 
76     if((tty = fopen("/dev/tty", "r")) == NULL)
77 	tty = stdin;
78 
79     fprintf(stderr, "%s", prompt);
80     fflush(stderr);
81 
82     if(echo == 0){
83 	tcgetattr(fileno(tty), &t_old);
84 	memcpy(&t_new, &t_old, sizeof(t_new));
85 	t_new.c_lflag &= ~ECHO;
86 	tcsetattr(fileno(tty), TCSANOW, &t_new);
87     }
88     intr_flag = 0;
89     p = buf;
90     while(intr_flag == 0){
91 	c = getc(tty);
92 	if(c == EOF){
93 	    if(!ferror(tty))
94 		ret = 1;
95 	    break;
96 	}
97 	if(c == '\n')
98 	    break;
99 	if(of == 0)
100 	    *p++ = c;
101 	of = (p == buf + len);
102     }
103     if(of)
104 	p--;
105     *p = 0;
106 
107     if(echo == 0){
108 	printf("\n");
109 	tcsetattr(fileno(tty), TCSANOW, &t_old);
110     }
111 
112     if(tty != stdin)
113 	fclose(tty);
114 
115     for(i = 1; i < sizeof(sigs) / sizeof(sigs[0]); i++)
116 	if (oksigs[i])
117 	    sigaction(i, &sigs[i], NULL);
118 
119     if(ret)
120 	return -3;
121     if(intr_flag)
122 	return -2;
123     if(of)
124 	return -1;
125     return 0;
126 }
127 
128 
129 #if 0
130 int main()
131 {
132     char s[128];
133     int ret;
134     ret = read_string("foo: ", s, sizeof(s), 0);
135     printf("%d ->%s<-\n", ret, s);
136 }
137 #endif
138