add xembed wrapper utility

xembed will cause a command to attempt to XEmbed into the window given
by the environment variable XEMBED, so long as it is in the foreground
of its controlling terminal. This causes a process to effectively take
the place of the terminal window, unless it is backgrounded.

Signed-off-by: Christoph Lohmann <20h@r-36.net>

1 files changed, 46 insertions, 0 deletions

diff --git a/xembed.c b/xembed.c
new file mode 100644
index 0000000..0b36603
--- /dev/null
+++ b/xembed.c
@@ -0,0 +1,46 @@
+/*
+ * See LICENSE file for copyright and license details.
+ */
+
+#include <fcntl.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int
+main(int argc, char **argv)
+{
+	char *xembed;
+	int tty;
+	pid_t pgrp, tcpgrp;
+
+	if(argc < 3) {
+		fprintf(stderr, "usage: %s flag cmd ...\n", argv[0]);
+		return 2;
+	}
+
+	if(!(xembed = getenv("XEMBED")))
+		goto noembed;
+
+	if((tty = open("/dev/tty", O_RDONLY)) < 0)
+		goto noembed;
+
+	pgrp = getpgrp();
+	tcpgrp = tcgetpgrp(tty);
+
+	close(tty);
+
+	if(pgrp == tcpgrp) { /* in foreground of tty */
+		argv[0] = argv[2];
+		argv[2] = xembed;
+	}
+	else {
+noembed:
+		argv += 2;
+	}
+
+	execvp(argv[0], argv);
+
+	perror(argv[0]); /* failed to execute */
+	return 1;
+}