/*******************************************************************************

	COPYRIGHT(C) JONAS 'SORTIE' TERMANSEN 2012.

	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 3 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, see <http://www.gnu.org/licenses/>.

	kernelinfo.cpp
	Prints a kernel information string.

*******************************************************************************/

#include <sys/kernelinfo.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <errno.h>
#include <error.h>

void usage(const char* argv0)
{
	printf("usage: %s <REQUEST> ...\n", argv0);
	printf("Prints a kernel information string.\n");
	printf("example: %s name\n", argv0);
	printf("example: %s version\n", argv0);
	printf("example: %s builddate\n", argv0);
	printf("example: %s buildtime\n", argv0);
}

void help(const char* argv0)
{
	usage(argv0);
}

void version(const char* argv0)
{
	usage(argv0);
}

int main(int argc, char* argv[])
{
	const char* argv0 = argv[0];
	if ( argc < 2 ) { usage(argv0); return 0; }
	for ( int i = 1; i < argc; i++ )
	{
		if ( argv[i][0] != '-' ) { continue; }
		if ( strcmp(argv[i], "--usage") == 0 ) { usage(argv0); return 0; }
		if ( strcmp(argv[i], "--help") == 0 ) { help(argv0); return 0; }
		if ( strcmp(argv[i], "--version") == 0 ) { version(argv0); return 0; }
		fprintf(stderr, "%s: unknown option: %s\n", argv0, argv[i]);
		return 1;
	}
	size_t bufsize = 32;
	char* buf = (char*) malloc(bufsize);
	if ( !buf ) { perror("malloc"); return 1; }
	for ( int i = 1; i < argc; i++ )
	{
retry:
		ssize_t ret = kernelinfo(argv[i], buf, bufsize);
		if ( ret < 0 )
		{
			if ( errno == EINVAL )
			{
				error(1, 0, "%s: No such kernel string", argv[i]);
			}
			error(1, errno, "kernelinfo(\"%s\")", argv[i]);
		}
		if ( ret )
		{
			buf = (char*) realloc(buf, ret);
			if ( !buf ) { perror("realloc"); return 1; }
			bufsize = ret;
			goto retry;
		}
		printf("%s\n", buf);
	}
	return 0;
}