1 files changed, 21 insertions, 1 deletions
diff --git a/open.c b/open.c
index 2b6ee75..bac9f2c 100644
--- a/open.c
+++ b/open.c
@@ -1,7 +1,7 @@
 /* open.c: to insulate <fcntl.h> from the rest of rc. */
 
-#include <fcntl.h>
 #include "rc.h"
+#include <fcntl.h>
 
 /*
    Opens a file with the necessary flags. Assumes the following
@@ -23,3 +23,23 @@ extern int rc_open(const char *name, redirtype m) {
 		panic("bad mode passed to rc_open");
 	return open(name, mode_masks[m], 0666);
 }
+
+/* make a file descriptor blocking. return value indicates whether
+the desciptor was previously set to non-blocking. */
+
+extern bool makeblocking(int fd) {
+	int flags;
+
+	if ((flags = fcntl(fd, F_GETFL)) == -1) {
+		uerror("fcntl");
+		rc_error(NULL);
+	}
+	if (! (flags & O_NONBLOCK))
+		return FALSE;
+	flags &= ~O_NONBLOCK;
+	if (fcntl(fd, F_SETFL, (long) flags) == -1) {
+		uerror("fcntl");
+		rc_error(NULL);
+	}
+	return TRUE;
+}