add isastream (obsolete STREAMS junk)

apparently some packages see stropts.h and want to be able to use
this. the implementation checks that the file descriptor is valid by
using fcntl/F_GETFD so it can report an error if not (as specified).

1 files changed, 7 insertions, 0 deletions

diff --git a/src/misc/isastream.c b/src/misc/isastream.c
new file mode 100644
index 00000000..4dafdb08
--- /dev/null
+++ b/src/misc/isastream.c
@@ -0,0 +1,7 @@
+#include <stropts.h>
+#include <fcntl.h>
+
+int isastream(int fd)
+{
+	return fcntl(fd, F_GETFD) < 0 ? -1 : 0;
+}