add key to insert text selected with dmenu as terminal input

st.c

@@ -2117,9 +2117,9 @@ strparse(void)
 }
 
 void
-externalpipe(const Arg *arg)
+externalpipeinout(const Arg *arg, void (*processout)(int fildes))
 {
-	int to[2];
+	int to[2], from[2];
 	char buf[UTF_SIZ];
 	void (*oldsigpipe)(int);
 	Glyph *bp, *end;
@@ -2127,16 +2127,27 @@ externalpipe(const Arg *arg)
 
 	if (pipe(to) == -1)
 		return;
+	if (processout != NULL && pipe(from) == -1)
+		return;
 
 	switch (fork()) {
 	case -1:
 		close(to[0]);
 		close(to[1]);
+		if (processout != NULL) {
+			close(from[0]);
+			close(from[1]);
+		}
 		return;
 	case 0:
 		dup2(to[0], STDIN_FILENO);
 		close(to[0]);
 		close(to[1]);
+		if (processout != NULL) {
+			dup2(from[1], STDOUT_FILENO);
+			close(from[0]);
+			close(from[1]);
+		}
 		execvp(((char **)arg->v)[0], (char **)arg->v);
 		fprintf(stderr, "st: execvp %s\n", ((char **)arg->v)[0]);
 		perror("failed");
@@ -2144,6 +2155,8 @@ externalpipe(const Arg *arg)
 	}
 
 	close(to[0]);
+	if (processout != NULL)
+		close(from[1]);
 	/* ignore sigpipe for now, in case child exists early */
 	oldsigpipe = signal(SIGPIPE, SIG_IGN);
 	newline = 0;
@@ -2165,10 +2178,39 @@ externalpipe(const Arg *arg)
 	if (newline)
 		(void)xwrite(to[1], "\n", 1);
 	close(to[1]);
+	if (processout != NULL) {
+		processout(from[0]);
+		close(from[0]);
+	}
 	/* restore */
 	signal(SIGPIPE, oldsigpipe);
 }
 
+void
+externalpipe(const Arg *arg)
+{
+	externalpipeinout(arg, NULL);
+}
+
+void
+ttycopy(int fildes)
+{
+	char buf[256];
+	int len;
+
+	len = read(fildes, buf, sizeof(buf));
+	if (len > 0 && len < sizeof(buf)) {
+		buf[len] = '\0';
+		ttywrite(buf, len, 1);
+	}
+}
+
+void
+externalpipettycopy(const Arg *arg)
+{
+	externalpipeinout(arg, ttycopy);
+}
+
 void
 strdump(void)
 {