ifconfig default to -a

[Ian Darwin <ian_(_at_)_darwinsys_(_dot_)_com>]

Several other *nixes including at least Linux, Mac OS X, and FreeBSD
have an ifconfig that assumes -a instead of printing usage if no
arguments are given. This patch makes ours print -a, and adds -h
to print the usage nicely. Has been in my tree for a while, and tested
lighly on macppc and i386, but none of these systems has more than 2
actual network cards.

Adds an int param to usage() so -h can exit 0, invalid flags can exit 1.

This replaces a patch I sent to some people previously, which was buggy
(sorry).

Index: ifconfig.8
===================================================================
RCS file: /cvs/src/sbin/ifconfig/ifconfig.8,v
retrieving revision 1.93
diff -u -r1.93 ifconfig.8
--- ifconfig.8	1 Dec 2004 22:30:53 -0000	1.93
+++ ifconfig.8	2 Dec 2004 03:51:23 -0000
@@ -123,6 +123,7 @@
 If a protocol family is specified,
 .Nm
 will report only the details specific to that protocol family.
+If no parameters are provided, a summary of all interfaces is provided.
 .Pp
 Only the superuser may modify the configuration of a network interface.
 .Pp
Index: ifconfig.c
===================================================================
RCS file: /cvs/src/sbin/ifconfig/ifconfig.c,v
retrieving revision 1.121
diff -u -r1.121 ifconfig.c
--- ifconfig.c	1 Dec 2004 15:57:44 -0000	1.121
+++ ifconfig.c	2 Dec 2004 03:51:24 -0000
@@ -348,7 +348,7 @@
 void	printif(struct ifreq *, int);
 void	printb(char *, unsigned short, char *);
 void	status(int, struct sockaddr_dl *);
-void	usage(void);
+void	usage(int);
 const char *get_string(const char *, const char *, u_int8_t *, int *);
 void	print_string(const u_int8_t *, int);
 char	*sec2str(time_t);
@@ -428,9 +428,16 @@
 	int Cflag = 0;
 	int i;
 
-	if (argc < 2)
-		usage();
+	/* If no args at all, print all interfaces.  */
+	if (argc < 2) {
+		printif(NULL, ifaliases);
+		exit(0);
+	}
 	argc--, argv++;
+	if (!strcmp(*argv, "-h")) {
+		usage(0);
+		exit(0);
+	}
 	if (!strcmp(*argv, "-a"))
 		aflag = 1;
 	else if (!strcmp(*argv, "-A")) {
@@ -447,7 +454,7 @@
 		mflag = 1;
 		argc--, argv++;
 		if (argc < 1)
-			usage();
+			usage(1);
 		if (strlcpy(name, *argv, sizeof(name)) >= IFNAMSIZ)
 			errx(1, "interface name '%s' too long", *argv);
 	} else if (!strcmp(*argv, "-C")) {
@@ -468,13 +475,13 @@
 	}
 	if (Cflag) {
 		if (argc > 0 || mflag || aflag)
-			usage();
+			usage(1);
 		list_cloners();
 		exit(0);
 	}
 	if (aflag) {
 		if (argc > 0)
-			usage();
+			usage(0);
 		printif(NULL, ifaliases);
 		exit(0);
 	}
@@ -2693,8 +2700,9 @@
 		printf("Attempt to set IPX netmask will be ineffectual\n");
 }
 
+/* Print usage, exit(value) if value is non-zero. */
 void
-usage(void)
+usage(int value)
 {
 	fprintf(stderr,
 	    "usage: ifconfig interface [address_family] [address [dest_address]]\n"
@@ -2724,7 +2732,8 @@
 	    "       ifconfig -m interface [address_family]\n"
 	    "       ifconfig interface create\n"
 	    "       ifconfig interface destroy\n");
-	exit(1);
+	if (value)
+		exit(value);
 }
 
 static int __tag = 0;