/**************************************************************
 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 * 
 *************************************************************/




#include <stdio.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <dlfcn.h>

/* 
 * NOTE: Since no one is really interested in correct unload behavior I've
 * disabled the shared library unload check. If you want to reenable it comment
 * the following line out
 */
#define NO_UNLOAD_CHECK

static const char *pprog_name 	= "checkdll";
static const char *psymbol		= "GetVersionInfo";

void usage()
{
	fprintf(stderr, "usage: %s [-s] <dllname>\n", pprog_name);
	return;
}

int main(int argc, char *argv[])
{
	int 	rc;
    int     silent=0;
	void	*phandle;	
	char 	*(*pfun)(void);

	if ( argc < 2 || argc > 4) {
		usage();
		return 1;
	}

    if ( !strcmp(argv[1],"-s") ) {
        silent = 1;
        ++argv, --argc;
    }

	if ( (rc = access( argv[1], R_OK )) == -1 ) {
		fprintf(stderr, "%s: ERROR: %s: %s\n",
                pprog_name, argv[1], strerror(errno));
		return 2;
	}

	if (!silent) printf("Checking DLL %s ...", argv[1]);
	fflush(stdout);

	if ( (phandle = dlopen(argv[1], RTLD_NOW)) != NULL ) {
		if  ( (pfun = (char *(*)(void))dlsym(phandle, psymbol)) != NULL ) {
			if (!silent) printf(": ok\n");
		}
		else
		{
			printf(": WARNING: %s\n", dlerror());
		}
#ifdef NO_UNLOAD_CHECK
		_exit(0);
#else
		dlclose(phandle);
#endif
		return 0;
	}

	printf(": ERROR: %s\n", dlerror());
	return 3;
}