Replace fopen() calls with FILE *stdio.

src/cat.c

@@ -71,7 +71,7 @@ int main(int argc, char **argv)
 	if(!strcmp(argv[i], "-"))
 	    {
 	    fppresence++;
-	    newbuf = cat(fopen("/dev/stdin", "r"), upresence);
+	    newbuf = cat(stdin, upresence);
 	    }
 	else if((fp = fopen(argv[i], "r")) != NULL)
 	    {
@@ -100,7 +100,7 @@ int main(int argc, char **argv)
 
     if(!fppresence)
 	{
-	buf = cat(fopen("/dev/stdin", "r"), upresence);
+	buf = cat(stdin, upresence);
 	}
 
     if(!upresence)