isatty() and ctermid() now actually work correctly.

git-svn-id: file:///srv/svn/repos/haiku/trunk/current@9084 a95241bf-73f2-0310-859d-f6bbb57e9c96

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

@@ -1,6 +1,6 @@
 /* 
-** Copyright 2003, Axel Dörfler, [email protected]. All rights reserved.
+** Copyright 2003-2004, Axel Dörfler, [email protected]. All rights reserved.
-** Distributed under the terms of the OpenBeOS License.
+** Distributed under the terms of the Haiku License.
 */
 
 
@@ -9,39 +9,36 @@
 #include <unistd.h>
 #include <termios.h>
 
+#include <syscalls.h>
 
-/*
+
- * isatty - is the given file descriptor bound to a terminal device?
+/**	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 fd)
 {
-	struct termios term;
+	struct termios termios;
 
-	return (tcgetattr(fd, &term) == 0);
+	return _kern_ioctl(fd, TCGETA, &termios, sizeof(struct termios)) == B_OK;
+		// we don't use tcgetattr() here in order to keep errno unchanged
 }
 
 
-/*
+/** returns the name of the controlling terminal */
- * 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];
+	char *name = ttyname(1);
+		// we assume that stdout is our controlling terminal...
 
 	if (s == NULL)
 		s = defaultBuffer;
 
-	return strcpy(s, "/dev/tty");
+	return strcpy(s, name ? name : "");
 }