implement (nonstandard) forkpty

include/pty.h

@@ -9,6 +9,7 @@ extern "C" {
 #include <sys/ioctl.h>
 
 int openpty(int *, int *, char *, const struct termios *, const struct winsize *);
+int forkpty(int *, char *, const struct termios *, const struct winsize *);
 
 #ifdef __cplusplus
 extern }

src/misc/forkpty.c

@@ -0,0 +1,22 @@
+#include <pty.h>
+#include <unistd.h>
+
+int forkpty(int *m, char *name, const struct termios *tio, const struct winsize *ws)
+{
+	int s;
+	pid_t pid;
+
+	if (openpty(m, &s, name, tio, ws) < 0) return -1;
+	pid = fork();
+	if (!pid) {
+		close(*m);
+		dup2(s, 0);
+		dup2(s, 1);
+		dup2(s, 2);
+		close(s);
+		return 0;
+	}
+	close(s);
+	if (pid < 0) close(*m);
+	return pid;
+}