Properly declare buf as extern and fix all unused-warnings

config.mk

@@ -12,7 +12,7 @@ X11LIB = /usr/X11R6/lib
 
 # flags
 CPPFLAGS = -I$(X11INC) -D_DEFAULT_SOURCE
-CFLAGS   = -std=c99 -pedantic -Wall -Wextra -Wno-unused -Os
+CFLAGS   = -std=c99 -pedantic -Wall -Wextra -Os
 LDFLAGS  = -L$(X11LIB) -s
 LDLIBS   = -lX11
 

slstatus.c

@@ -10,6 +10,7 @@
 #include <X11/Xlib.h>
 
 #include "arg.h"
+#include "slstatus.h"
 #include "util.h"
 
 struct arg {
@@ -19,15 +20,17 @@ struct arg {
 };
 
 char *argv0;
+char buf[1024];
 static unsigned short int done;
 static Display *dpy;
 
-#include "slstatus.h"
 #include "config.h"
 
 static void
 terminate(const int signo)
 {
+	(void)signo;
+
 	done = 1;
 }
 

util.h

@@ -1,4 +1,4 @@
-static char buf[1024];
+extern char buf[1024];
 
 #define LEN(x) (sizeof (x) / sizeof *(x))