2 * PLink - a command-line (stdin/stdout) variant of PuTTY.
15 #include <sys/ioctl.h>
17 #ifndef HAVE_NO_SYS_SELECT_H
18 #include <sys/select.h>
21 #define PUTTY_DO_GLOBALS /* actually _define_ globals */
26 #define MAX_STDIN_BACKLOG 4096
30 static struct termios orig_termios;
32 void fatalbox(char *p, ...)
37 fprintf(stderr, "FATAL ERROR: ");
39 vfprintf(stderr, p, ap);
49 void modalfatalbox(char *p, ...)
54 fprintf(stderr, "FATAL ERROR: ");
56 vfprintf(stderr, p, ap);
66 void nonfatal(char *p, ...)
71 fprintf(stderr, "ERROR: ");
73 vfprintf(stderr, p, ap);
78 void connection_fatal(void *frontend, char *p, ...)
83 fprintf(stderr, "FATAL ERROR: ");
85 vfprintf(stderr, p, ap);
95 void cmdline_error(char *p, ...)
100 fprintf(stderr, "plink: ");
102 vfprintf(stderr, p, ap);
109 static int local_tty = FALSE; /* do we have a local tty? */
111 static Backend *back;
112 static void *backhandle;
116 * Default settings that are specific to pterm.
118 char *platform_default_s(const char *name)
120 if (!strcmp(name, "TermType"))
121 return dupstr(getenv("TERM"));
122 if (!strcmp(name, "UserName"))
123 return get_username();
124 if (!strcmp(name, "SerialLine"))
125 return dupstr("/dev/ttyS0");
129 int platform_default_i(const char *name, int def)
134 FontSpec *platform_default_fontspec(const char *name)
136 return fontspec_new("");
139 Filename *platform_default_filename(const char *name)
141 if (!strcmp(name, "LogFileName"))
142 return filename_from_str("putty.log");
144 return filename_from_str("");
147 char *x_get_default(const char *key)
149 return NULL; /* this is a stub */
151 int term_ldisc(Terminal *term, int mode)
155 void frontend_echoedit_update(void *frontend, int echo, int edit)
157 /* Update stdin read mode to reflect changes in line discipline. */
160 if (!local_tty) return;
165 mode.c_lflag |= ECHO;
167 mode.c_lflag &= ~ECHO;
170 mode.c_iflag |= ICRNL;
171 mode.c_lflag |= ISIG | ICANON;
172 mode.c_oflag |= OPOST;
174 mode.c_iflag &= ~ICRNL;
175 mode.c_lflag &= ~(ISIG | ICANON);
176 mode.c_oflag &= ~OPOST;
177 /* Solaris sets these to unhelpful values */
179 mode.c_cc[VTIME] = 0;
180 /* FIXME: perhaps what we do with IXON/IXOFF should be an
181 * argument to frontend_echoedit_update(), to allow
182 * implementation of SSH-2 "xon-xoff" and Rlogin's
184 mode.c_iflag &= ~IXON;
185 mode.c_iflag &= ~IXOFF;
188 * Mark parity errors and (more important) BREAK on input. This
189 * is more complex than it need be because POSIX-2001 suggests
190 * that escaping of valid 0xff in the input stream is dependent on
191 * IGNPAR being clear even though marking of BREAK isn't. NetBSD
192 * 2.0 goes one worse and makes it dependent on INPCK too. We
193 * deal with this by forcing these flags into a useful state and
194 * then faking the state in which we found them in from_tty() if
195 * we get passed a parity or framing error.
197 mode.c_iflag = (mode.c_iflag | INPCK | PARMRK) & ~IGNPAR;
199 tcsetattr(STDIN_FILENO, TCSANOW, &mode);
202 /* Helper function to extract a special character from a termios. */
203 static char *get_ttychar(struct termios *t, int index)
205 cc_t c = t->c_cc[index];
206 #if defined(_POSIX_VDISABLE)
207 if (c == _POSIX_VDISABLE)
210 return dupprintf("^<%d>", c);
213 char *get_ttymode(void *frontend, const char *mode)
216 * Propagate appropriate terminal modes from the local terminal,
219 if (!local_tty) return NULL;
221 #define GET_CHAR(ourname, uxname) \
223 if (strcmp(mode, ourname) == 0) \
224 return get_ttychar(&orig_termios, uxname); \
226 #define GET_BOOL(ourname, uxname, uxmemb, transform) \
228 if (strcmp(mode, ourname) == 0) { \
229 int b = (orig_termios.uxmemb & uxname) != 0; \
231 return dupprintf("%d", b); \
236 * Modes that want to be the same on all terminal devices involved.
238 /* All the special characters supported by SSH */
240 GET_CHAR("INTR", VINTR);
243 GET_CHAR("QUIT", VQUIT);
246 GET_CHAR("ERASE", VERASE);
249 GET_CHAR("KILL", VKILL);
252 GET_CHAR("EOF", VEOF);
255 GET_CHAR("EOL", VEOL);
258 GET_CHAR("EOL2", VEOL2);
261 GET_CHAR("START", VSTART);
264 GET_CHAR("STOP", VSTOP);
267 GET_CHAR("SUSP", VSUSP);
270 GET_CHAR("DSUSP", VDSUSP);
272 #if defined(VREPRINT)
273 GET_CHAR("REPRINT", VREPRINT);
276 GET_CHAR("WERASE", VWERASE);
279 GET_CHAR("LNEXT", VLNEXT);
282 GET_CHAR("FLUSH", VFLUSH);
285 GET_CHAR("SWTCH", VSWTCH);
288 GET_CHAR("STATUS", VSTATUS);
290 #if defined(VDISCARD)
291 GET_CHAR("DISCARD", VDISCARD);
293 /* Modes that "configure" other major modes. These should probably be
294 * considered as user preferences. */
295 /* Configuration of ICANON */
297 GET_BOOL("ECHOK", ECHOK, c_lflag, );
300 GET_BOOL("ECHOKE", ECHOKE, c_lflag, );
303 GET_BOOL("ECHOE", ECHOE, c_lflag, );
306 GET_BOOL("ECHONL", ECHONL, c_lflag, );
309 GET_BOOL("XCASE", XCASE, c_lflag, );
311 /* Configuration of ECHO */
313 GET_BOOL("ECHOCTL", ECHOCTL, c_lflag, );
315 /* Configuration of IXON/IXOFF */
317 GET_BOOL("IXANY", IXANY, c_iflag, );
319 /* Configuration of OPOST */
321 GET_BOOL("OLCUC", OLCUC, c_oflag, );
324 GET_BOOL("ONLCR", ONLCR, c_oflag, );
327 GET_BOOL("OCRNL", OCRNL, c_oflag, );
330 GET_BOOL("ONOCR", ONOCR, c_oflag, );
333 GET_BOOL("ONLRET", ONLRET, c_oflag, );
337 * Modes that want to be set in only one place, and that we have
341 GET_BOOL("ISIG", ISIG, c_lflag, );
344 GET_BOOL("ICANON", ICANON, c_lflag, );
347 GET_BOOL("ECHO", ECHO, c_lflag, );
350 GET_BOOL("IXON", IXON, c_iflag, );
353 GET_BOOL("IXOFF", IXOFF, c_iflag, );
356 GET_BOOL("OPOST", OPOST, c_oflag, );
360 * We do not propagate the following modes:
361 * - Parity/serial settings, which are a local affair and don't
362 * make sense propagated over SSH's 8-bit byte-stream.
363 * IGNPAR PARMRK INPCK CS7 CS8 PARENB PARODD
364 * - Things that want to be enabled in one place that we don't
369 * - Things I don't know what to do with. (FIXME)
370 * ISTRIP IMAXBEL NOFLSH TOSTOP IEXTEN
377 /* Fall through to here for unrecognised names, or ones that are
378 * unsupported on this platform */
382 void cleanup_termios(void)
385 tcsetattr(STDIN_FILENO, TCSANOW, &orig_termios);
388 bufchain stdout_data, stderr_data;
389 enum { EOF_NO, EOF_PENDING, EOF_SENT } outgoingeof;
391 int try_output(int is_stderr)
393 bufchain *chain = (is_stderr ? &stderr_data : &stdout_data);
394 int fd = (is_stderr ? STDERR_FILENO : STDOUT_FILENO);
398 if (bufchain_size(chain) > 0) {
399 int prev_nonblock = nonblock(fd);
401 bufchain_prefix(chain, &senddata, &sendlen);
402 ret = write(fd, senddata, sendlen);
404 bufchain_consume(chain, ret);
405 } while (ret == sendlen && bufchain_size(chain) != 0);
408 if (ret < 0 && errno != EAGAIN) {
409 perror(is_stderr ? "stderr: write" : "stdout: write");
413 if (outgoingeof == EOF_PENDING && bufchain_size(&stdout_data) == 0) {
414 close(STDOUT_FILENO);
415 outgoingeof = EOF_SENT;
417 return bufchain_size(&stdout_data) + bufchain_size(&stderr_data);
420 int from_backend(void *frontend_handle, int is_stderr,
421 const char *data, int len)
424 bufchain_add(&stderr_data, data, len);
425 return try_output(TRUE);
427 assert(outgoingeof == EOF_NO);
428 bufchain_add(&stdout_data, data, len);
429 return try_output(FALSE);
433 int from_backend_untrusted(void *frontend_handle, const char *data, int len)
436 * No "untrusted" output should get here (the way the code is
437 * currently, it's all diverted by FLAG_STDERR).
439 assert(!"Unexpected call to from_backend_untrusted()");
440 return 0; /* not reached */
443 int from_backend_eof(void *frontend_handle)
445 assert(outgoingeof == EOF_NO);
446 outgoingeof = EOF_PENDING;
448 return FALSE; /* do not respond to incoming EOF with outgoing */
451 int get_userpass_input(prompts_t *p, unsigned char *in, int inlen)
454 ret = cmdline_get_passwd_input(p, in, inlen);
456 ret = console_get_userpass_input(p, in, inlen);
461 * Handle data from a local tty in PARMRK format.
463 static void from_tty(void *vbuf, unsigned len)
465 char *p, *q, *end, *buf = vbuf;
466 static enum {NORMAL, FF, FF00} state = NORMAL;
468 p = buf; end = buf + len;
476 q = memchr(p, '\xff', end - p);
477 if (q == NULL) q = end;
478 back->send(backhandle, p, q - p);
484 back->send(backhandle, p, 1);
487 } else if (*p == '\0') {
494 back->special(backhandle, TS_BRK);
497 * Pretend that PARMRK wasn't set. This involves
498 * faking what INPCK and IGNPAR would have done if
499 * we hadn't overridden them. Unfortunately, we
500 * can't do this entirely correctly because INPCK
501 * distinguishes between framing and parity
502 * errors, but PARMRK format represents both in
503 * the same way. We assume that parity errors are
504 * more common than framing errors, and hence
505 * treat all input errors as being subject to
508 if (orig_termios.c_iflag & INPCK) {
509 /* If IGNPAR is set, we throw away the character. */
510 if (!(orig_termios.c_iflag & IGNPAR)) {
511 /* PE/FE get passed on as NUL. */
513 back->send(backhandle, p, 1);
516 /* INPCK not set. Assume we got a parity error. */
517 back->send(backhandle, p, 1);
528 void sigwinch(int signum)
530 if (write(signalpipe[1], "x", 1) <= 0)
531 /* not much we can do about it */;
535 * In Plink our selects are synchronous, so these functions are
538 int uxsel_input_add(int fd, int rwx) { return 0; }
539 void uxsel_input_remove(int id) { }
542 * Short description of parameters.
544 static void usage(void)
546 printf("Plink: command-line connection utility\n");
548 printf("Usage: plink [options] [user@]host [command]\n");
549 printf(" (\"host\" can also be a PuTTY saved session name)\n");
550 printf("Options:\n");
551 printf(" -V print version information and exit\n");
552 printf(" -pgpfp print PGP key fingerprints and exit\n");
553 printf(" -v show verbose messages\n");
554 printf(" -load sessname Load settings from saved session\n");
555 printf(" -ssh -telnet -rlogin -raw -serial\n");
556 printf(" force use of a particular protocol\n");
557 printf(" -P port connect to specified port\n");
558 printf(" -l user connect with specified username\n");
559 printf(" -batch disable all interactive prompts\n");
560 printf(" -sercfg configuration-string (e.g. 19200,8,n,1,X)\n");
561 printf(" Specify the serial configuration (serial only)\n");
562 printf("The following options only apply to SSH connections:\n");
563 printf(" -pw passw login with specified password\n");
564 printf(" -D [listen-IP:]listen-port\n");
565 printf(" Dynamic SOCKS-based port forwarding\n");
566 printf(" -L [listen-IP:]listen-port:host:port\n");
567 printf(" Forward local port to remote address\n");
568 printf(" -R [listen-IP:]listen-port:host:port\n");
569 printf(" Forward remote port to local address\n");
570 printf(" -X -x enable / disable X11 forwarding\n");
571 printf(" -A -a enable / disable agent forwarding\n");
572 printf(" -t -T enable / disable pty allocation\n");
573 printf(" -1 -2 force use of particular protocol version\n");
574 printf(" -4 -6 force use of IPv4 or IPv6\n");
575 printf(" -C enable compression\n");
576 printf(" -i key private key file for user authentication\n");
577 printf(" -noagent disable use of Pageant\n");
578 printf(" -agent enable use of Pageant\n");
579 printf(" -hostkey aa:bb:cc:...\n");
580 printf(" manually specify a host key (may be repeated)\n");
581 printf(" -m file read remote command(s) from file\n");
582 printf(" -s remote command is an SSH subsystem (SSH-2 only)\n");
583 printf(" -N don't start a shell/command (SSH-2 only)\n");
584 printf(" -nc host:port\n");
585 printf(" open tunnel in place of session (SSH-2 only)\n");
589 static void version(void)
591 printf("plink: %s\n", ver);
595 void frontend_net_error_pending(void) {}
597 const int share_can_be_downstream = TRUE;
598 const int share_can_be_upstream = TRUE;
600 int main(int argc, char **argv)
606 int i, fdcount, fdsize, fdstate;
610 int use_subsystem = 0;
611 int got_host = FALSE;
616 fdcount = fdsize = 0;
618 * Initialise port and protocol to sensible defaults. (These
619 * will be overridden by more or less anything.)
621 default_protocol = PROT_SSH;
624 bufchain_init(&stdout_data);
625 bufchain_init(&stderr_data);
626 outgoingeof = EOF_NO;
628 flags = FLAG_STDERR | FLAG_STDERR_TTY;
632 * Process the command line.
635 do_defaults(NULL, conf);
636 loaded_session = FALSE;
637 default_protocol = conf_get_int(conf, CONF_protocol);
638 default_port = conf_get_int(conf, CONF_port);
642 * Override the default protocol if PLINK_PROTOCOL is set.
644 char *p = getenv("PLINK_PROTOCOL");
646 const Backend *b = backend_from_name(p);
648 default_protocol = b->protocol;
649 default_port = b->default_port;
650 conf_set_int(conf, CONF_protocol, default_protocol);
651 conf_set_int(conf, CONF_port, default_port);
658 int ret = cmdline_process_param(p, (argc > 1 ? argv[1] : NULL),
662 "plink: option \"%s\" requires an argument\n", p);
664 } else if (ret == 2) {
666 } else if (ret == 1) {
668 } else if (!strcmp(p, "-batch")) {
669 console_batch_mode = 1;
670 } else if (!strcmp(p, "-s")) {
671 /* Save status to write to conf later. */
673 } else if (!strcmp(p, "-V") || !strcmp(p, "--version")) {
675 } else if (!strcmp(p, "--help")) {
678 } else if (!strcmp(p, "-pgpfp")) {
681 } else if (!strcmp(p, "-o")) {
684 "plink: option \"-o\" requires an argument\n");
688 provide_xrm_string(*++argv);
691 fprintf(stderr, "plink: unknown option \"%s\"\n", p);
695 if (!conf_launchable(conf) || !(got_host || loaded_session)) {
699 * If the hostname starts with "telnet:", set the
700 * protocol to Telnet and process the string as a
703 if (!strncmp(q, "telnet:", 7)) {
707 if (q[0] == '/' && q[1] == '/')
709 conf_set_int(conf, CONF_protocol, PROT_TELNET);
711 p += host_strcspn(p, ":/");
716 conf_set_int(conf, CONF_port, atoi(p));
718 conf_set_int(conf, CONF_port, -1);
719 conf_set_str(conf, CONF_host, q);
722 char *r, *user, *host;
724 * Before we process the [user@]host string, we
725 * first check for the presence of a protocol
726 * prefix (a protocol name followed by ",").
732 b = backend_from_name(p);
734 default_protocol = b->protocol;
735 conf_set_int(conf, CONF_protocol,
737 portnumber = b->default_port;
743 * A nonzero length string followed by an @ is treated
744 * as a username. (We discount an _initial_ @.) The
745 * rest of the string (or the whole string if no @)
746 * is treated as a session name and/or hostname.
750 p++, r = NULL; /* discount initial @ */
755 user = NULL, host = p;
759 * Now attempt to load a saved session with the
760 * same name as the hostname.
763 Conf *conf2 = conf_new();
764 do_defaults(host, conf2);
765 if (loaded_session || !conf_launchable(conf2)) {
766 /* No settings for this host; use defaults */
767 /* (or session was already loaded with -load) */
768 conf_set_str(conf, CONF_host, host);
769 conf_set_int(conf, CONF_port, default_port);
772 conf_copy_into(conf, conf2);
773 loaded_session = TRUE;
779 /* Patch in specified username. */
780 conf_set_str(conf, CONF_username, user);
787 cmdlen = cmdsize = 0;
792 if (cmdlen >= cmdsize) {
793 cmdsize = cmdlen + 512;
794 command = sresize(command, cmdsize, char);
796 command[cmdlen++]=*p++;
798 if (cmdlen >= cmdsize) {
799 cmdsize = cmdlen + 512;
800 command = sresize(command, cmdsize, char);
802 command[cmdlen++]=' '; /* always add trailing space */
803 if (--argc) p = *++argv;
805 if (cmdlen) command[--cmdlen]='\0';
806 /* change trailing blank to NUL */
807 conf_set_str(conf, CONF_remote_cmd, command);
808 conf_set_str(conf, CONF_remote_cmd2, "");
809 conf_set_int(conf, CONF_nopty, TRUE); /* command => no tty */
811 break; /* done with cmdline */
819 if (!conf_launchable(conf) || !(got_host || loaded_session)) {
824 * Muck about with the hostname in various ways.
827 char *hostbuf = dupstr(conf_get_str(conf, CONF_host));
828 char *host = hostbuf;
832 * Trim leading whitespace.
834 host += strspn(host, " \t");
837 * See if host is of the form user@host, and separate out
838 * the username if so.
840 if (host[0] != '\0') {
841 char *atsign = strrchr(host, '@');
844 conf_set_str(conf, CONF_username, host);
850 * Trim a colon suffix off the hostname if it's there. In
851 * order to protect unbracketed IPv6 address literals
852 * against this treatment, we do not do this if there's
853 * _more_ than one colon.
856 char *c = host_strchr(host, ':');
859 char *d = host_strchr(c+1, ':');
866 * Remove any remaining whitespace.
871 if (*q != ' ' && *q != '\t')
877 conf_set_str(conf, CONF_host, hostbuf);
882 * Perform command-line overrides on session configuration.
884 cmdline_run_saved(conf);
887 * Apply subsystem status.
890 conf_set_int(conf, CONF_ssh_subsys, TRUE);
892 if (!*conf_get_str(conf, CONF_remote_cmd) &&
893 !*conf_get_str(conf, CONF_remote_cmd2) &&
894 !*conf_get_str(conf, CONF_ssh_nc_host))
895 flags |= FLAG_INTERACTIVE;
898 * Select protocol. This is farmed out into a table in a
899 * separate file to enable an ssh-free variant.
901 back = backend_from_proto(conf_get_int(conf, CONF_protocol));
904 "Internal fault: Unsupported protocol found\n");
911 if (portnumber != -1)
912 conf_set_int(conf, CONF_port, portnumber);
915 * Block SIGPIPE, so that we'll get EPIPE individually on
916 * particular network connections that go wrong.
918 putty_signal(SIGPIPE, SIG_IGN);
921 * Set up the pipe we'll use to tell us about SIGWINCH.
923 if (pipe(signalpipe) < 0) {
927 putty_signal(SIGWINCH, sigwinch);
930 * Now that we've got the SIGWINCH handler installed, try to find
931 * out the initial terminal size.
933 if (ioctl(STDIN_FILENO, TIOCGWINSZ, &size) >= 0) {
934 conf_set_int(conf, CONF_width, size.ws_col);
935 conf_set_int(conf, CONF_height, size.ws_row);
942 * Unix Plink doesn't provide any way to add forwardings after the
943 * connection is set up, so if there are none now, we can safely set
946 if (conf_get_int(conf, CONF_protocol) == PROT_SSH &&
947 !conf_get_int(conf, CONF_x11_forward) &&
948 !conf_get_int(conf, CONF_agentfwd) &&
949 !conf_get_str_nthstrkey(conf, CONF_portfwd, 0))
950 conf_set_int(conf, CONF_ssh_simple, TRUE);
953 * Start up the connection.
955 logctx = log_init(NULL, conf);
956 console_provide_logctx(logctx);
960 /* nodelay is only useful if stdin is a terminal device */
961 int nodelay = conf_get_int(conf, CONF_tcp_nodelay) && isatty(0);
963 error = back->init(NULL, &backhandle, conf,
964 conf_get_str(conf, CONF_host),
965 conf_get_int(conf, CONF_port),
967 conf_get_int(conf, CONF_tcp_keepalives));
969 fprintf(stderr, "Unable to open connection:\n%s\n", error);
972 back->provide_logctx(backhandle, logctx);
973 ldisc_create(conf, NULL, back, backhandle, NULL);
979 * Set up the initial console mode. We don't care if this call
980 * fails, because we know we aren't necessarily running in a
983 local_tty = (tcgetattr(STDIN_FILENO, &orig_termios) == 0);
984 atexit(cleanup_termios);
985 frontend_echoedit_update(NULL, 1, 1);
987 now = GETTICKCOUNT();
990 fd_set rset, wset, xset;
1001 FD_SET_MAX(signalpipe[0], maxfd, rset);
1003 if (connopen && !sending &&
1004 back->connected(backhandle) &&
1005 back->sendok(backhandle) &&
1006 back->sendbuffer(backhandle) < MAX_STDIN_BACKLOG) {
1007 /* If we're OK to send, then try to read from stdin. */
1008 FD_SET_MAX(STDIN_FILENO, maxfd, rset);
1011 if (bufchain_size(&stdout_data) > 0) {
1012 /* If we have data for stdout, try to write to stdout. */
1013 FD_SET_MAX(STDOUT_FILENO, maxfd, wset);
1016 if (bufchain_size(&stderr_data) > 0) {
1017 /* If we have data for stderr, try to write to stderr. */
1018 FD_SET_MAX(STDERR_FILENO, maxfd, wset);
1021 /* Count the currently active fds. */
1023 for (fd = first_fd(&fdstate, &rwx); fd >= 0;
1024 fd = next_fd(&fdstate, &rwx)) i++;
1026 /* Expand the fdlist buffer if necessary. */
1029 fdlist = sresize(fdlist, fdsize, int);
1033 * Add all currently open fds to the select sets, and store
1034 * them in fdlist as well.
1037 for (fd = first_fd(&fdstate, &rwx); fd >= 0;
1038 fd = next_fd(&fdstate, &rwx)) {
1039 fdlist[fdcount++] = fd;
1041 FD_SET_MAX(fd, maxfd, rset);
1043 FD_SET_MAX(fd, maxfd, wset);
1045 FD_SET_MAX(fd, maxfd, xset);
1048 if (toplevel_callback_pending()) {
1052 ret = select(maxfd, &rset, &wset, &xset, &tv);
1053 } else if (run_timers(now, &next)) {
1060 now = GETTICKCOUNT();
1061 if (now - then > next - then)
1065 tv.tv_sec = ticks / 1000;
1066 tv.tv_usec = ticks % 1000 * 1000;
1067 ret = select(maxfd, &rset, &wset, &xset, &tv);
1071 now = GETTICKCOUNT();
1072 } while (ret < 0 && errno == EINTR);
1074 ret = select(maxfd, &rset, &wset, &xset, NULL);
1082 for (i = 0; i < fdcount; i++) {
1085 * We must process exceptional notifications before
1086 * ordinary readability ones, or we may go straight
1087 * past the urgent marker.
1089 if (FD_ISSET(fd, &xset))
1090 select_result(fd, 4);
1091 if (FD_ISSET(fd, &rset))
1092 select_result(fd, 1);
1093 if (FD_ISSET(fd, &wset))
1094 select_result(fd, 2);
1097 if (FD_ISSET(signalpipe[0], &rset)) {
1099 struct winsize size;
1100 if (read(signalpipe[0], c, 1) <= 0)
1102 /* ignore its value; it'll be `x' */
1103 if (ioctl(STDIN_FILENO, TIOCGWINSZ, (void *)&size) >= 0)
1104 back->size(backhandle, size.ws_col, size.ws_row);
1107 if (FD_ISSET(STDIN_FILENO, &rset)) {
1111 if (connopen && back->connected(backhandle)) {
1112 ret = read(STDIN_FILENO, buf, sizeof(buf));
1114 perror("stdin: read");
1116 } else if (ret == 0) {
1117 back->special(backhandle, TS_EOF);
1118 sending = FALSE; /* send nothing further after this */
1123 back->send(backhandle, buf, ret);
1128 if (FD_ISSET(STDOUT_FILENO, &wset)) {
1129 back->unthrottle(backhandle, try_output(FALSE));
1132 if (FD_ISSET(STDERR_FILENO, &wset)) {
1133 back->unthrottle(backhandle, try_output(TRUE));
1136 run_toplevel_callbacks();
1138 if ((!connopen || !back->connected(backhandle)) &&
1139 bufchain_size(&stdout_data) == 0 &&
1140 bufchain_size(&stderr_data) == 0)
1141 break; /* we closed the connection */
1143 exitcode = back->exitcode(backhandle);
1145 fprintf(stderr, "Remote process exit code unavailable\n");
1146 exitcode = 1; /* this is an error condition */
1148 cleanup_exit(exitcode);
1149 return exitcode; /* shouldn't happen, but placates gcc */