st/st-externalpipe.diff

diff --git a/st.c b/st.c
index 8d4a9f2..3b05f0b 100644
--- a/st.c
+++ b/st.c
@@ -138,6 +138,7 @@ static void printscreen(const Arg *) ;
 static void iso14755(const Arg *);
 static void toggleprinter(const Arg *);
 static void sendbreak(const Arg *);
+static void externalpipe(const Arg *);
 
 /* config.h for applying patches and the configuration. */
 #include "config.h"
@@ -2344,6 +2345,59 @@ eschandle(uchar ascii)
 }
 
 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 ", ((char **)arg->v)[0]);
+		perror("failed");
+		exit(0);
+	}
+
+	close(to[0]);
+	/* ignore sigpipe for now, in case child exits 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
 tputc(Rune u)
 {
 	char c[UTF_SIZ];
diff --git a/win.h b/win.h
index 428111c..a012a24 100644
--- a/win.h
+++ b/win.h
@@ -28,3 +28,5 @@ void xresize(int, int);
 void xselpaste(void);
 unsigned long xwinid(void);
 void xsetsel(char *, Time);
+
+extern char winid[64];
diff --git a/x.c b/x.c
index fbfd350..ff052e6 100644
--- a/x.c
+++ b/x.c
@@ -139,6 +139,7 @@ static void (*handler[LASTEvent])(XEvent *) = {
 static DC dc;
 static XWindow xw;
 static XSelection xsel;
+char winid[64];
 
 /* Font Ring Cache */
 enum {
@@ -915,6 +916,7 @@ xinit(void)
 			win.w, win.h, 0, XDefaultDepth(xw.dpy, xw.scr), InputOutput,
 			xw.vis, CWBackPixel | CWBorderPixel | CWBitGravity
 			| CWEventMask | CWColormap, &xw.attrs);
+	snprintf(winid, LEN(winid), "%lu", (unsigned long)xw.win);
 
 	memset(&gcvalues, 0, sizeof(gcvalues));
 	gcvalues.graphics_exposures = False;