And that's it! pty.c is now a real pty backend rather than a

loopback interface; pterm now runs $SHELL and gives every impression
of being not a bad terminal emulator. I'm quite pleased with that. :-)

[originally from svn r2015]

unix/pterm.c

@@ -8,6 +8,9 @@
 #include <stdlib.h>
 #include <stdio.h>
 #include <time.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
 #include <gtk/gtk.h>
 #include <gdk/gdkkeysyms.h>
 
@@ -593,6 +596,32 @@ gint timer_func(gpointer data)
     return TRUE;
 }
 
+void pty_input_func(gpointer data, gint sourcefd, GdkInputCondition condition)
+{
+    /* struct gui_data *inst = (struct gui_data *)data; */
+    char buf[4096];
+    int ret;
+
+    ret = read(sourcefd, buf, sizeof(buf));
+
+    /*
+     * Clean termination condition is that either ret == 0, or ret
+     * < 0 and errno == EIO. Not sure why the latter, but it seems
+     * to happen. Boo.
+     */
+    if (ret == 0 || (ret < 0 && errno == EIO)) {
+	exit(0);
+    }
+
+    if (ret < 0) {
+	perror("read pty master");
+	exit(1);
+    }
+    if (ret > 0)
+	from_backend(0, buf, ret);
+    term_out();
+}
+
 void destroy(GtkWidget *widget, gpointer data)
 {
     gtk_main_quit();
@@ -793,6 +822,7 @@ void modalfatalbox(char *p, ...)
 int main(int argc, char **argv)
 {
     GtkWidget *window;
+    extern int pty_master_fd;	       /* declared in pty.c */
 
     gtk_init(&argc, &argv);
 
@@ -825,6 +855,7 @@ int main(int argc, char **argv)
     gtk_signal_connect(GTK_OBJECT(inst->area), "expose_event",
 		       GTK_SIGNAL_FUNC(expose_area), inst);
     gtk_timeout_add(20, timer_func, inst);
+    gdk_input_add(pty_master_fd, GDK_INPUT_READ, pty_input_func, inst);
     gtk_widget_add_events(GTK_WIDGET(inst->area),
 			  GDK_KEY_PRESS_MASK | GDK_KEY_RELEASE_MASK);
 

unix/pty.c

@@ -1,5 +1,11 @@
+#define _XOPEN_SOURCE
+#include <features.h>
+
 #include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+#include <fcntl.h>
 
 #include "putty.h"
 
@@ -10,6 +16,8 @@
 #define TRUE 1
 #endif
 
+int pty_master_fd;
+
 static void pty_size(void);
 
 static void c_write(char *buf, int len)
@@ -27,7 +35,74 @@ static void c_write(char *buf, int len)
  */
 static char *pty_init(char *host, int port, char **realhost, int nodelay)
 {
-    /* FIXME: do nothing for now */
+    int slavefd;
+    char name[FILENAME_MAX];
+    pid_t pid;
+
+    pty_master_fd = open("/dev/ptmx", O_RDWR);
+
+    if (pty_master_fd < 0) {
+	perror("/dev/ptmx: open");
+	exit(1);
+    }
+
+    if (grantpt(pty_master_fd) < 0) {
+	perror("grantpt");
+	exit(1);
+    }
+    
+    if (unlockpt(pty_master_fd) < 0) {
+	perror("unlockpt");
+	exit(1);
+    }
+
+    name[FILENAME_MAX-1] = '\0';
+    strncpy(name, ptsname(pty_master_fd), FILENAME_MAX-1);
+
+    slavefd = open(name, O_RDWR);
+    if (slavefd < 0) {
+	perror("slave pty: open");
+	return 1;
+    }
+
+    /*
+     * Fork and execute the command.
+     */
+    pid = fork();
+    if (pid < 0) {
+	perror("fork");
+	return 1;
+    }
+
+    if (pid == 0) {
+	int i;
+	/*
+	 * We are the child.
+	 */
+	close(pty_master_fd);
+	close(0);
+	close(1);
+	close(2);
+	fcntl(slavefd, F_SETFD, 0);    /* don't close on exec */
+	dup2(slavefd, 0);
+	dup2(slavefd, 1);
+	dup2(slavefd, 2);
+	setsid();
+	setpgrp();
+	tcsetpgrp(0, getpgrp());
+	/* Close everything _else_, for tidiness. */
+	for (i = 3; i < 1024; i++)
+	    close(i);
+	execl(getenv("SHELL"), getenv("SHELL"), NULL);
+	/*
+	 * If we're here, exec has gone badly foom.
+	 */
+	perror("exec");
+	exit(127);
+    } else {
+	close(slavefd);
+    }
+
     return NULL;
 }
 
@@ -36,7 +111,15 @@ static char *pty_init(char *host, int port, char **realhost, int nodelay)
  */
 static int pty_send(char *buf, int len)
 {
-    c_write(buf, len);		       /* FIXME: diagnostic thingy */
+    while (len > 0) {
+	int ret = write(pty_master_fd, buf, len);
+	if (ret < 0) {
+	    perror("write pty master");
+	    exit(1);
+	}
+	buf += ret;
+	len -= ret;
+    }
     return 0;
 }