3 files changed, 62 insertions, 1 deletions

diff --git a/README.md b/README.md
index 83c15be..9510ef5 100644
--- a/README.md
+++ b/README.md
@@ -10,6 +10,7 @@ This is my fork of [st][stterm] terminal with following patches applied:
 - desktopentry
 - scrollback (with mouse)
 - clipboard
+- externalpipe
 
 ## Dependencies:
 
diff --git a/st.c b/st.c
index 7f35b8a..0bb8a2e 100644
--- a/st.c
+++ b/st.c
@@ -731,8 +731,14 @@ sigchld(int a)
 	if ((p = waitpid(pid, &stat, WNOHANG)) < 0)
 		die("waiting for pid %hd failed: %s\n", pid, strerror(errno));
 
-	if (pid != p)
+	if (pid != p) {
+		if (p == 0 && wait(&stat) < 0)
+			die("wait: %s\n", strerror(errno));
+
+		/* reinstall sigchld handler */
+		signal(SIGCHLD, sigchld);
 		return;
+	}
 
 	if (WIFEXITED(stat) && WEXITSTATUS(stat))
 		die("child exited with status %d\n", WEXITSTATUS(stat));
@@ -2018,6 +2024,59 @@ strparse(void)
 }
 
 void
+externalpipe(const Arg *arg)
+{
+	int to[2];
+	char buf[UTF_SIZ];
+	void (*oldsigpipe)(int);
+	Glyph *bp, *end;
+	int lastpos, n, newline;
+
+	if (pipe(to) == -1)
+		return;
+
+	switch (fork()) {
+	case -1:
+		close(to[0]);
+		close(to[1]);
+		return;
+	case 0:
+		dup2(to[0], STDIN_FILENO);
+		close(to[0]);
+		close(to[1]);
+		execvp(((char **)arg->v)[0], (char **)arg->v);
+		fprintf(stderr, "st: execvp %s\n", ((char **)arg->v)[0]);
+		perror("failed");
+		exit(0);
+	}
+
+	close(to[0]);
+	/* ignore sigpipe for now, in case child exists early */
+	oldsigpipe = signal(SIGPIPE, SIG_IGN);
+	newline = 0;
+	for (n = 0; n < term.row; n++) {
+		bp = term.line[n];
+		lastpos = MIN(tlinelen(n) + 1, term.col) - 1;
+		if (lastpos < 0)
+			break;
+		end = &bp[lastpos + 1];
+		for (; bp < end; ++bp)
+			if (xwrite(to[1], buf, utf8encode(bp->u, buf)) < 0)
+				break;
+		if ((newline = term.line[n][lastpos].mode & ATTR_WRAP))
+			continue;
+		if (xwrite(to[1], "\n", 1) < 0)
+			break;
+		newline = 0;
+	}
+	if (newline)
+		(void)xwrite(to[1], "\n", 1);
+	close(to[1]);
+	/* restore */
+	signal(SIGPIPE, oldsigpipe);
+}
+
+void
 strdump(void)
 {
 	size_t i;
diff --git a/st.h b/st.h
index d8bf1f0..b41e6c0 100644
--- a/st.h
+++ b/st.h
@@ -82,6 +82,7 @@ void die(const char *, ...);
 void redraw(void);
 void draw(void);
 
+void externalpipe(const Arg *);
 void kscrolldown(const Arg *);
 void kscrollup(const Arg *);
 void newterm(const Arg *);