/*
 *	aegis - project change supervisor
 *	Copyright (C) 1997, 2001 Peter Miller;
 *	All rights reserved.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	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, USA.
 *
 * MANIFEST: functions to impliment the basename substitution
 */

#include <ac/string.h>

#include <str.h>
#include <sub.h>
#include <sub/basename.h>
#include <os.h>
#include <trace.h>
#include <wstr_list.h>


/*
 * NAME
 *	sub_basename - the basename substitution
 *
 * SYNOPSIS
 *	wstring_ty *sub_basename(wstring_list_ty *arg);
 *
 * DESCRIPTION
 *	The sub_basename function implements the basename substitution.
 *	The basename substitution is replaced by the basename of
 *	the argument path, similar to the basename(1) command.
 *
 * ARGUMENTS
 *	arg	- list of arguments, including the function name as [0]
 *
 * RETURNS
 *	a pointer to a string in dynamic memory;
 *	or NULL on error, setting suberr appropriately.
 */

wstring_ty *
sub_basename(scp, arg)
	sub_context_ty	*scp;
	wstring_list_ty	*arg;
{
	wstring_ty	*result;
	string_ty	*suffix;
	string_ty	*s1;
	string_ty	*s2;
	long		len;

	trace(("sub_basename()\n{\n"/*}*/));
	switch (arg->nitems)
	{
	default:
		sub_context_error_set(scp, i18n("requires one or two arguments"));
		result = 0;
		break;
	
	case 2:
		s1 = wstr_to_str(arg->item[1]);
		os_become_orig();
		s2 = os_entryname(s1);
		os_become_undo();
		str_free(s1);
		result = str_to_wstr(s2);
		str_free(s2);
		break;
	
	case 3:
		s1 = wstr_to_str(arg->item[1]);
		os_become_orig();
		s2 = os_entryname(s1);
		os_become_undo();
		str_free(s1);
		suffix = wstr_to_str(arg->item[2]);
		len = (long)s2->str_length - (long)suffix->str_length;
		if
		(
			len > 0
		&&
			!memcmp
			(
				s2->str_text + len,
				suffix->str_text,
				suffix->str_length
			)
		)
			result = wstr_n_from_c(s2->str_text, len);
		else
			result = str_to_wstr(s2);
		str_free(s2);
		str_free(suffix);
		break;
	}
	trace(("return %8.8lX;\n", (long)result));
	trace((/*{*/"}\n"));
	return result;
}