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/*
* Listener loop for subsystem library libss.a.
*
* util/ss/listen.c
*
* 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 <termios.h>
#include <sys/param.h>
static ss_data *current_info;
static jmp_buf listen_jmpb;
static RETSIGTYPE print_prompt()
{
struct termios termbuf;
if (tcgetattr(STDIN_FILENO, &termbuf) == 0) {
termbuf.c_lflag |= ICANON|ISIG|ECHO;
tcsetattr(STDIN_FILENO, TCSANOW, &termbuf);
}
(void) fputs(current_info->prompt, stdout);
(void) fflush(stdout);
}
static RETSIGTYPE listen_int_handler(signo)
int signo;
{
putc('\n', stdout);
longjmp(listen_jmpb, 1);
}
int ss_listen (sci_idx)
int sci_idx;
{
register char *cp;
register ss_data *info;
char input[BUFSIZ];
char buffer[BUFSIZ];
char *volatile end = buffer;
int code;
jmp_buf old_jmpb;
ss_data *old_info = current_info;
#ifdef POSIX_SIGNALS
struct sigaction isig, csig, nsig, osig;
sigset_t nmask, omask;
#else
register RETSIGTYPE (*sig_cont)();
RETSIGTYPE (*sig_int)(), (*old_sig_cont)();
int mask;
#endif
current_info = info = ss_info(sci_idx);
info->abort = 0;
#ifdef POSIX_SIGNALS
csig.sa_handler = (RETSIGTYPE (*)())0;
sigemptyset(&nmask);
sigaddset(&nmask, SIGINT);
sigprocmask(SIG_BLOCK, &nmask, &omask);
#else
sig_cont = (RETSIGTYPE (*)())0;
mask = sigblock(sigmask(SIGINT));
#endif
memcpy(old_jmpb, listen_jmpb, sizeof(jmp_buf));
#ifdef POSIX_SIGNALS
nsig.sa_handler = listen_int_handler;
sigemptyset(&nsig.sa_mask);
nsig.sa_flags = 0;
sigaction(SIGINT, &nsig, &isig);
#else
sig_int = signal(SIGINT, listen_int_handler);
#endif
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';
#ifdef POSIX_SIGNALS
nsig.sa_handler = listen_int_handler; /* fgets is not signal-safe */
osig = csig;
sigaction(SIGCONT, &nsig, &csig);
if ((RETSIGTYPE (*)())csig.sa_handler==(RETSIGTYPE (*)())listen_int_handler)
csig = osig;
#else
old_sig_cont = sig_cont;
sig_cont = signal(SIGCONT, print_prompt);
if (sig_cont == print_prompt)
sig_cont = old_sig_cont;
#endif
if (fgets(input, BUFSIZ, stdin) != input) {
code = SS_ET_EOF;
goto egress;
}
cp = strchr(input, '\n');
if (cp) {
*cp = '\0';
if (cp == input)
continue;
}
#ifdef POSIX_SIGNALS
sigaction(SIGCONT, &csig, (struct sigaction *)0);
#else
(void) signal(SIGCONT, sig_cont);
#endif
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:
#ifdef POSIX_SIGNALS
sigaction(SIGINT, &isig, (struct sigaction *)0);
#else
(void) signal(SIGINT, sig_int);
#endif
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;
}
void ss_quit(argc, argv, sci_idx, infop)
int argc;
char const * const *argv;
int sci_idx;
pointer infop;
{
ss_abort_subsystem(sci_idx, 0);
}
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