command: add ln support

Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>

commands/Kconfig

@@ -57,6 +57,10 @@ config CMD_READLINE
 	tristate
 	prompt "readline"
 
+config CMD_LN
+	tristate
+	prompt "ln"
+
 config CMD_TRUE
 	tristate
 	default y

commands/Makefile

@@ -73,3 +73,4 @@ obj-$(CONFIG_CMD_GLOBAL)	+= global.o
 obj-$(CONFIG_CMD_BASENAME)	+= basename.o
 obj-$(CONFIG_CMD_DIRNAME)	+= dirname.o
 obj-$(CONFIG_CMD_READLINK)	+= readlink.o
+obj-$(CONFIG_CMD_LN)		+= ln.o

commands/ln.c

@@ -0,0 +1,51 @@
+/*
+ * ln.c - make links between files
+ *
+ * Copyright (c) 2012 Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
+ */
+
+#include <common.h>
+#include <command.h>
+#include <libgen.h>
+#include <environment.h>
+#include <fs.h>
+#include <errno.h>
+
+static int do_ln(int argc, char *argv[])
+{
+	if (argc != 3)
+		return COMMAND_ERROR_USAGE;
+
+	if (symlink(argv[1], argv[2]) < 0) {
+		perror("ln");
+		return 1;
+	}
+	return 0;
+}
+
+BAREBOX_CMD_HELP_START(ln)
+BAREBOX_CMD_HELP_USAGE("ln SRC DEST\n")
+BAREBOX_CMD_HELP_SHORT("symlink - make a new name for a file\n")
+BAREBOX_CMD_HELP_END
+
+BAREBOX_CMD_START(ln)
+	.cmd		= do_ln,
+	.usage		= "symlink - make a new name for a file",
+	BAREBOX_CMD_HELP(cmd_ln_help)
+BAREBOX_CMD_END