[w3m-dev 03379] setuid w3mimgdisplay and check console tty

* XMakefile: w3mimgdisplay install by INSTALL_W3MIMGDISPLAY
* configure: ask setuid w3mimgdisplay
	(w3mimgdisplay_setuid): added
	(INSTALL_W3MIMGDISPLAY): added
* etc.c (mySystem): close until FOPEN_MAX
* image.c (openImgdisplay): setenv W3M_TTY
		stderr to /dev/null
		close until FOPEN_MAX
* install-sh: -o, -g for owner, group
* proto.h (ttyname_tty): added
* search.c (open_migemo): stderr to /dev/null
		close until FOPEN_MAX
* terms.c (ttyname_tty): added
* w3mimgdisplay.c: include <sys/types.h>, <unistd.h>
		W3MIMGDISPLAY_SETUID
		stderr to /dev/null
* w3mimg/w3mimg.c: include <sys/types.h>, <unistd.h>
		W3MIMGDISPLAY_SETUID
* w3mimg/fb/fb_w3mimg.c (check_tty_console): added
From: Fumitoshi UKAI  <ukai@debian.or.jp>

w3mimgdisplay.c

@@ -1,8 +1,10 @@
-/* $Id: w3mimgdisplay.c,v 1.8 2002/10/31 09:36:22 ukai Exp $ */
+/* $Id: w3mimgdisplay.c,v 1.9 2002/11/06 03:50:49 ukai Exp $ */
 #include <stdio.h>
 #include <stdlib.h>
 #include <ctype.h>
 #include <string.h>
+#include <sys/types.h>
+#include <unistd.h>
 #include "config.h"
 #include "w3mimg/w3mimg.h"
 
@@ -25,12 +27,29 @@ main(int argc, char **argv)
 {
     int len;
     char buf[1024 + 128];
+#ifdef W3MIMGDISPLAY_SETUID
+    uid_t runner_uid = getuid();
+    uid_t owner_uid = geteuid();
 
+    /* swap real and effective */
+    setreuid(owner_uid, runner_uid);
+#endif
     GetOption(argc, argv);
     if (!defined_debug)
-	fclose(stderr);
+	freopen("/dev/null", "w", stderr);
 
+#ifdef W3MIMGDISPLAY_SETUID
+    /* 
+     * back real and effective
+     * run w3mimg_open() in setuid privileges
+     */
+    setreuid(runner_uid, owner_uid);
+#endif
     w_op = w3mimg_open();
+#ifdef W3MIMGDISPLAY_SETUID
+    /* make sure drop privileges now */
+    setreuid(runner_uid, runner_uid);
+#endif
     if (w_op == NULL)
 	exit(1);
     if (defined_x)