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

    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>

#if !defined(VERSIONSTR)
#define VERSIONSTR "unknown version"
#endif

void help(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 version(const char* argv0)
{
	FILE* fp = stdout;
	fprintf(fp, "%s (Sortix) %s\n", argv0, VERSIONSTR);
	fprintf(fp, "License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.\n");
	fprintf(fp, "This is free software: you are free to change and redistribute it.\n");
	fprintf(fp, "There is NO WARRANTY, to the extent permitted by law.\n");
}

int main(int argc, char* argv[])
{
	const char* argv0 = argv[0];
	if ( argc < 2 ) { help(argv0); return 0; }
	for ( int i = 1; i < argc; i++ )
	{
		if ( argv[i][0] != '-' ) { continue; }
		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 )
		error(1, errno, "malloc");
	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 )
				error(1, errno, "realloc");
			bufsize = ret;
			goto retry;
		}
		printf("%s\n", buf);
	}
	return 0;
}