Add a -a option as a no-op for Solaris compatibility, as briefly

discussed on src-committers.  This is intentionally not included in the
usage() function as it would confuse the output too much.

Approved by:	jhb
MFC after:	1 week

usr.bin/id/id.1

@@ -35,7 +35,7 @@
 .\"	@(#)id.1	8.1 (Berkeley) 6/6/93
 .\" $FreeBSD$
 .\"
-.Dd May 3, 2004
+.Dd September 26, 2006
 .Dt ID 1
 .Os
 .Sh NAME
@@ -89,6 +89,10 @@ as white-space separated numbers, in no particular order.
 Display the MAC label of the current process.
 .It Fl P
 Display the id as a password file entry.
+.It Fl a
+Ignored for compatibility with other
+.Nm
+implementations.
 .It Fl g
 Display the effective group ID as a number.
 .It Fl n

usr.bin/id/id.c

@@ -96,7 +96,7 @@ main(int argc, char *argv[])
 	}
 
 	while ((ch = getopt(argc, argv,
-	    (isgroups || iswhoami) ? "" : "APGMgnpru")) != -1)
+	    (isgroups || iswhoami) ? "" : "APGMagnpru")) != -1)
 		switch(ch) {
 #ifdef USE_BSM_AUDIT
 		case 'A':
@@ -112,6 +112,8 @@ main(int argc, char *argv[])
 		case 'P':
 			Pflag = 1;
 			break;
+		case 'a':
+			break;
 		case 'g':
 			gflag = 1;
 			break;