summaryrefslogtreecommitdiff
path: root/lib/ss/listen.c
blob: 765b757561e5caa27ceb0f8c574b9f5a63707134 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
/*
 * Listener loop for subsystem library libss.a.
 *
 *	$Header$
 *	$Locker$
 * 
 * Copyright 1987, 1988 by MIT Student Information Processing Board
 *
 * For copyright information, see copyright.h.
 */

#include "copyright.h"
#include "ss_internal.h"
#include <stdio.h>
#include <setjmp.h>
#include <signal.h>
#include <sys/param.h>
#ifdef BSD
#include <sgtty.h>
#endif

#ifndef	lint
static char const rcs_id[] =
    "$Header$";
#endif

typedef void sigret_t;

static ss_data *current_info;
static jmp_buf listen_jmpb;

static sigret_t print_prompt()
{
#ifdef BSD
    /* put input into a reasonable mode */
    struct sgttyb ttyb;
    if (ioctl(fileno(stdin), TIOCGETP, &ttyb) != -1) {
	if (ttyb.sg_flags & (CBREAK|RAW)) {
	    ttyb.sg_flags &= ~(CBREAK|RAW);
	    (void) ioctl(0, TIOCSETP, &ttyb);
	}
    }
#endif
    (void) fputs(current_info->prompt, stdout);
    (void) fflush(stdout);
}

static sigret_t listen_int_handler()
{
    putc('\n', stdout);
    signal(SIGINT, listen_int_handler);
    longjmp(listen_jmpb, 1);
}

int ss_listen (sci_idx)
    int sci_idx;
{
    char *cp;
    ss_data *info;
    sigret_t (*sig_int)(), (*sig_cont)(), (*old_sig_cont)();
    char input[BUFSIZ];
    char buffer[BUFSIZ];
    char *end = buffer;
#ifdef POSIX_SIGNALS
    sigset_t omask, igmask;
#else
    int mask;
#endif
    int code;
    jmp_buf old_jmpb;
    ss_data *old_info = current_info;
    
    current_info = info = ss_info(sci_idx);
    sig_cont = (sigret_t (*)()) 0;
    info->abort = 0;
#ifdef POSIX_SIGNALS
    sigemptyset(&igmask);
    sigaddset(&igmask, SIGINT);
    sigprocmask(SIG_BLOCK, &igmask, &omask);
#else
    mask = sigblock(sigmask(SIGINT));
#endif
    memcpy(old_jmpb, listen_jmpb, sizeof(jmp_buf));
    sig_int = signal(SIGINT, listen_int_handler);
    setjmp(listen_jmpb);
#ifdef POSIX_SIGNALS
    sigprocmask(SIG_SETMASK, &omask, (sigset_t *) 0);
#else
    (void) sigsetmask(mask);
#endif
    while(!info->abort) {
	print_prompt();
	*end = '\0';
	old_sig_cont = sig_cont;
	sig_cont = signal(SIGCONT, print_prompt);
	if (sig_cont == print_prompt)
	    sig_cont = old_sig_cont;
	if (fgets(input, BUFSIZ, stdin) != input) {
	    code = SS_ET_EOF;
	    goto egress;
	}
	cp = strchr(input, '\n');
	if (cp) {
	    *cp = '\0';
	    if (cp == input)
		continue;
	}
	(void) signal(SIGCONT, sig_cont);
	for (end = input; *end; end++)
	    ;

	code = ss_execute_line (sci_idx, input);
	if (code == SS_ET_COMMAND_NOT_FOUND) {
	    register char *c = input;
	    while (*c == ' ' || *c == '\t')
		c++;
	    cp = strchr (c, ' ');
	    if (cp)
		*cp = '\0';
	    cp = strchr (c, '\t');
	    if (cp)
		*cp = '\0';
	    ss_error (sci_idx, 0,
		    "Unknown request \"%s\".  Type \"?\" for a request list.",
		       c);
	}
    }
    code = 0;
egress:
    (void) signal(SIGINT, sig_int);
    memcpy(listen_jmpb, old_jmpb, sizeof(jmp_buf));
    current_info = old_info;
    return code;
}

void ss_abort_subsystem(sci_idx, code)
    int sci_idx;
    int code;
{
    ss_info(sci_idx)->abort = 1;
    ss_info(sci_idx)->exit_status = code;
    
}

int ss_quit(argc, argv, sci_idx, infop)
    int argc;
    char **argv;
    int sci_idx;
    pointer infop;
{
    ss_abort_subsystem(sci_idx, 0);
}