Typos/grammar fixes.

man2/select_tut.2

@@ -276,7 +276,8 @@ main(void) {
 .SH PORT FORWARDING EXAMPLE
 
 Here is an example that better demonstrates the true utility of
-\fBselect\fP. The listing below a TCP forwarding program that forwards
+\fBselect\fP.
+The listing below is a TCP forwarding program that forwards
 from one TCP port to another.
 .PP
 .nf

man4/null.4

@@ -42,7 +42,7 @@ chown root:mem /dev/null /dev/zero
 .RE
 .SH NOTES
 If these devices are not writable and readable for all users, many
-programs will act strange.
+programs will act strangely.
 .SH FILES
 .I /dev/null
 .br

man7/ip.7

@@ -86,7 +86,7 @@ local interfaces. When
 .BR listen (2)
 or
 .BR connect (2)
-are called on a unbound socket the socket is automatically bound to a
+are called on an unbound socket, it is automatically bound to a
 random free port with the local address set to
 .BR INADDR_ANY .