fleshed out some tty stuff...

isatty() is fixed - altho this is basically academic since we don't have any
drivers for terminal devices written yet (but at least the code is ready when we do)

also, ctermid() is implemented - which is of no big consequence


git-svn-id: file:///srv/svn/repos/haiku/trunk/current@3170 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/kernel/libroot/posix/unistd/terminal.c

@@ -4,14 +4,44 @@
 */
 
 
-#include <unistd.h>
 #include <stdio.h>
+#include <string.h>
+#include <unistd.h>
+#include <termios.h>
 
 
+/*
+ * isatty - is the given file descriptor bound to a terminal device?
+ * 
+ * a simple call to fetch the terminal control attributes suffices
+ * (only a valid tty device will succeed)
+ *
+ */
 int
-isatty(int file)
+isatty(int fd)
 {
-	// ToDo: please fix me!
+	struct termios term;
-	return file < 3;
+	
+	return (tcgetattr(fd, &term) == 0);
+}
+
+
+/*
+ * ctermid - return the name of the controlling terminal
+ *
+ * this is a totally useless function!
+ * (but kept for historical Posix compatibility)
+ * yes, it *always* returns "/dev/tty"
+ *
+ */
+char *
+ctermid(char *s)
+{
+	static char defaultBuffer[L_ctermid];
+	
+	if (s == NULL)
+		s = defaultBuffer;
+	
+	return strcpy(s, "/dev/tty");
 }