Add a directory 'contrib/cygtermd', containing the source code for my

hacky helper program to let PuTTY act as a local pterm-oid on
Cygwin-enabled Windows systems.

[originally from svn r9191]

contrib/cygtermd/main.c

@@ -0,0 +1,174 @@
+/*
+ * Main program.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stddef.h>
+#include <stdarg.h>
+#include <signal.h>
+#include <string.h>
+#include <errno.h>
+
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+#include "sel.h"
+#include "pty.h"
+#include "telnet.h"
+
+int signalpipe[2];
+
+sel *asel;
+sel_rfd *netr, *ptyr, *sigr;
+int ptyfd;
+sel_wfd *netw, *ptyw;
+Telnet telnet;
+
+#define BUF 65536
+
+void sigchld(int signum)
+{
+    write(signalpipe[1], "C", 1);
+}
+
+void fatal(const char *fmt, ...)
+{
+    va_list ap;
+    fprintf(stderr, "FIXME: ");
+    va_start(ap, fmt);
+    vfprintf(stderr, fmt, ap);
+    va_end(ap);
+    fprintf(stderr, "\n");
+    exit(1);
+}
+
+void net_readdata(sel_rfd *rfd, void *data, size_t len)
+{
+    if (len == 0)
+	exit(0);		       /* EOF on network - client went away */
+    telnet_from_net(telnet, data, len);
+    if (sel_write(netw, NULL, 0) > BUF)
+	sel_rfd_freeze(ptyr);
+    if (sel_write(ptyw, NULL, 0) > BUF)
+	sel_rfd_freeze(netr);
+}
+
+void net_readerr(sel_rfd *rfd, int error)
+{
+    fprintf(stderr, "standard input: read: %s\n", strerror(errno));
+    exit(1);
+}
+
+void net_written(sel_wfd *wfd, size_t bufsize)
+{
+    if (bufsize < BUF)
+	sel_rfd_unfreeze(ptyr);
+}
+
+void net_writeerr(sel_wfd *wfd, int error)
+{
+    fprintf(stderr, "standard input: write: %s\n", strerror(errno));
+    exit(1);
+}
+
+void pty_readdata(sel_rfd *rfd, void *data, size_t len)
+{
+    if (len == 0)
+	exit(0);		       /* EOF on pty */
+    telnet_from_pty(telnet, data, len);
+    if (sel_write(netw, NULL, 0) > BUF)
+	sel_rfd_freeze(ptyr);
+    if (sel_write(ptyw, NULL, 0) > BUF)
+	sel_rfd_freeze(netr);
+}
+
+void pty_readerr(sel_rfd *rfd, int error)
+{
+    if (error == EIO)		       /* means EOF, on a pty */
+	exit(0);
+    fprintf(stderr, "pty: read: %s\n", strerror(errno));
+    exit(1);
+}
+
+void pty_written(sel_wfd *wfd, size_t bufsize)
+{
+    if (bufsize < BUF)
+	sel_rfd_unfreeze(netr);
+}
+
+void pty_writeerr(sel_wfd *wfd, int error)
+{
+    fprintf(stderr, "pty: write: %s\n", strerror(errno));
+    exit(1);
+}
+
+void sig_readdata(sel_rfd *rfd, void *data, size_t len)
+{
+    char *p = data;
+
+    while (len > 0) {
+	if (*p == 'C') {
+	    int status;
+	    pid_t pid = waitpid(-1, &status, WNOHANG);
+	    if (WIFEXITED(status) || WIFSIGNALED(status))
+		exit(0);	       /* child process vanished */
+	}
+    }
+}
+
+void sig_readerr(sel_rfd *rfd, int error)
+{
+    fprintf(stderr, "signal pipe: read: %s\n", strerror(errno));
+    exit(1);
+}
+
+int main(int argc, char **argv)
+{
+    int ret;
+    int shell_started = 0;
+    char *directory = NULL;
+    char **program_args = NULL;
+
+    if (argc > 1 && argv[1][0]) {
+        directory = argv[1];
+        argc--, argv++;
+    }
+    if (argc > 1) {
+        program_args = argv + 1;
+    }
+
+    pty_preinit();
+
+    asel = sel_new(NULL);
+    netr = sel_rfd_add(asel, 0, net_readdata, net_readerr, NULL);
+    netw = sel_wfd_add(asel, 1, net_written, net_writeerr, NULL);
+    ptyr = sel_rfd_add(asel, -1, pty_readdata, pty_readerr, NULL);
+    ptyw = sel_wfd_add(asel, -1, pty_written, pty_writeerr, NULL);
+
+    telnet = telnet_new(netw, ptyw);
+
+    if (pipe(signalpipe) < 0) {
+	perror("pipe");
+	return 1;
+    }
+    sigr = sel_rfd_add(asel, signalpipe[0], sig_readdata,
+		       sig_readerr, NULL);
+
+    signal(SIGCHLD, sigchld);
+
+    do {
+	struct shell_data shdata;
+
+	ret = sel_iterate(asel, -1);
+	if (!shell_started && telnet_shell_ok(telnet, &shdata)) {
+	    ptyfd = run_program_in_pty(&shdata, directory, program_args);
+	    sel_rfd_setfd(ptyr, ptyfd);
+	    sel_wfd_setfd(ptyw, ptyfd);
+	    shell_started = 1;
+	}
+    } while (ret == 0);
+
+    return 0;
+}