Add missing static keywords to at(1).

While there, tidy up the privs.h part, where at.c has to #define to
declare some globals. Also group static and non-static global variables
in at.c.

usr.bin/at/at.c

@@ -63,8 +63,6 @@ __FBSDID("$FreeBSD$");
 #include "panic.h"
 #include "parsetime.h"
 #include "perm.h"
-
-#define MAIN
 #include "privs.h"
 
 /* Macros */
@@ -90,22 +88,22 @@ enum { ATQ, ATRM, AT, BATCH, CAT };	/* what program we want to run */
 
 /* File scope variables */
 
-const char *no_export[] =
-{
+static const char *no_export[] = {
     "TERM", "TERMCAP", "DISPLAY", "_"
 };
 static int send_mail = 0;
+static char *atinput = NULL;	/* where to get input from */
+static char atqueue = 0;	/* which queue to examine for jobs (atq) */
 
 /* External variables */
 
 extern char **environ;
 int fcreated;
 char atfile[] = ATJOB_DIR "12345678901234";
-
-char *atinput = (char*)0;	/* where to get input from */
-char atqueue = 0;		/* which queue to examine for jobs (atq) */
 char atverify = 0;		/* verify time instead of queuing job */
 char *namep;
+uid_t real_uid, effective_uid;
+gid_t real_gid, effective_gid;
 
 /* Function declarations */
 

usr.bin/at/parsetime.c

@@ -72,7 +72,7 @@ enum {	/* symbols */
 
 /* parse translation table - table driven parsers can be your FRIEND!
  */
-struct {
+static const struct {
     const char *name;	/* token name */
     int value;	/* token id */
     int plural;	/* is this plural? */

usr.bin/at/privs.h

@@ -59,15 +59,8 @@
  * to the real userid before calling any of them.
  */
 
-#ifndef MAIN
-extern
-#endif
-uid_t real_uid, effective_uid;
-
-#ifndef MAIN 
-extern
-#endif
-gid_t real_gid, effective_gid;
+extern uid_t real_uid, effective_uid;
+extern gid_t real_gid, effective_gid;
 
 #define RELINQUISH_PRIVS { \
 	real_uid = getuid(); \