Add locale(1). I have used it for while as useful debugging tool

for locale related things.  So, I think it could be useful for
others.  It's not yet implement (or implement in different manner)
all POSIX things, but I think it's good enough for start.

POSIX conformance related updates and manpage to follow relatively soon.

usr.bin/locale/Makefile

@@ -0,0 +1,6 @@
+# $FreeBSD$
+
+PROG = locale
+NOMAN=YES
+
+.include <bsd.prog.mk>

usr.bin/locale/locale.c

@@ -0,0 +1,214 @@
+/*-
+ * Copyright (c) 2002 Alexey Zelkin <phantom@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * $FreeBSD$
+ */
+
+#include <sys/types.h>
+#include <dirent.h>
+#include <locale.h>
+#include <rune.h>		/* for _PATH_LOCALE */
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stringlist.h>
+#include <unistd.h>
+
+/* Local prototypes */
+void	usage(void);
+void	get_locales_list(void);
+void	list_locales(void);
+void	display_locale_status(int);
+
+/* Global variables */
+static StringList *locales = NULL;
+
+int	all_locales = 0;
+int	verbose = 0;
+int	env_used = 0;
+
+struct _lcinfo {
+	char	*name;
+	int	id;
+} lcinfo [] = {
+	"LANG",		LC_ALL,
+	"LC_ALL",	LC_ALL,
+	"LC_CTYPE",	LC_CTYPE,
+	"LC_COLLATE",	LC_COLLATE,
+	"LC_TIME",	LC_TIME,
+	"LC_NUMERIC",	LC_NUMERIC,
+	"LC_MONETARY",	LC_MONETARY,
+	"LC_MESSAGES",	LC_MESSAGES
+};
+#define NLCINFO (sizeof(lcinfo)/sizeof(lcinfo[0]))
+
+int
+main(int argc, char *argv[])
+{
+	char	ch;
+
+	while ((ch = getopt(argc, argv, "av")) != -1)
+		switch (ch) {
+		case 'a':
+			all_locales = 1;
+			break;
+		case 'v':
+			verbose = 1;
+			break;
+		default:
+			usage();
+		}
+	argc -= optind;
+	argv += optind;
+
+	if (all_locales) {
+		list_locales();
+		exit(0);
+	}
+
+	display_locale_status(verbose);
+	return (0);
+}
+
+void
+usage(void)
+{
+	printf("\nUsage: locale [ -a ] [ -v ]\n");
+	exit(1);
+}
+
+void
+list_locales(void)
+{
+	int i;
+
+	get_locales_list();
+	for (i = 0; i < locales->sl_cur; i++) {
+		printf("%s\n", locales->sl_str[i]);
+	}
+}
+
+void
+probe_var(char *varname, int id)
+{
+	char *value, *res1, *res2;
+
+	value = getenv(varname);
+	if (value == NULL) {
+		printf("%s = (null)\n", varname);
+		return;
+	}
+
+	if (sl_find(locales, value) == NULL)
+		res1 = "invalid";
+	else
+		res1 = "valid";
+
+	if (strcmp(value, setlocale(id, value)) != 0)
+		res2 = "invalid";
+	else
+		res2 = "valid";
+
+	printf("%s = \"%s\"\t\t(name is %s, content is %s)\n",
+			varname, value, res1, res2);
+}
+
+void
+display_locale_status(int verbose)
+{
+	int i;
+
+	setlocale(LC_ALL, "");
+
+	if (verbose) {
+		get_locales_list();
+		if (env_used)
+			printf("WARNING: PATH_LOCALE environment variable is set!");
+	}
+
+	printf("Current status of locale settings:\n\n");
+	for (i = 1; i < NLCINFO; i++) {    /* start with 1 to avoid 'LANG' */
+		printf("%s = \"%s\"\n",
+			lcinfo[i].name,
+			setlocale(lcinfo[i].id, ""));
+	}
+
+	/*
+	 * If verbose flag is set, add environment information
+	 */
+	if (verbose) {
+		printf("\nCurrent environment variables (and status):\n\n");
+		for (i = 0; i < NLCINFO; i++) 
+			probe_var(lcinfo[i].name, lcinfo[i].id);
+	}
+}
+
+static char *
+get_locale_path(void)
+{
+	char *localedir;
+
+	localedir = getenv("PATH_LOCALE");
+	if (localedir == NULL)
+		localedir = _PATH_LOCALE;
+	else
+		env_used = 1;
+	return (localedir);
+}
+
+static int
+scmp(const void *s1, const void *s2)
+{
+	return strcmp(*(const char **)s1, *(const char **)s2);
+}
+
+void
+get_locales_list()
+{
+	DIR *dirp;
+	struct dirent *dp;
+	char *dirname;
+
+	if (locales != NULL)
+		return;
+
+	locales = sl_init();
+	if (locales == NULL)
+		err(1, "could not allocate memory");
+
+	dirname = get_locale_path();
+	dirp = opendir(dirname);
+	if (dirp == NULL)
+		err(1, "could not open directory '%s'", dirname);
+
+	while ((dp = readdir(dirp)) != NULL) {
+		if (*dp->d_name == '.')
+			continue;
+		sl_add(locales, strdup(dp->d_name));
+	}
+	closedir(dirp);
+
+	qsort(locales->sl_str, locales->sl_cur, sizeof(char *), scmp);
+}