/* vi: set sw=4 ts=4: */
/* uname -- print system information
 * Copyright (C) 1989-1999 Free Software Foundation, Inc.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

/* BB_AUDIT SUSv3 compliant */
/* http://www.opengroup.org/onlinepubs/007904975/utilities/uname.html */

/* Option		Example

   -s, --sysname	SunOS
   -n, --nodename	rocky8
   -r, --release	4.0
   -v, --version
   -m, --machine	sun
   -a, --all		SunOS rocky8 4.0  sun

   The default behavior is equivalent to `-s'.

   David MacKenzie <djm@gnu.ai.mit.edu> */

/* Busyboxed by Erik Andersen */

/* Further size reductions by Glenn McGrath and Manuel Novoa III. */

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * Now does proper error checking on i/o.  Plus some further space savings.
 */

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/utsname.h>
#include "busybox.h"

typedef struct {
	struct utsname name;
	char processor[8];			/* for "unknown" */
} uname_info_t;

static const char options[] = "snrvmpa";
static const unsigned short int utsname_offset[] = {
	offsetof(uname_info_t,name.sysname),
	offsetof(uname_info_t,name.nodename),
	offsetof(uname_info_t,name.release),
	offsetof(uname_info_t,name.version),
	offsetof(uname_info_t,name.machine),
	offsetof(uname_info_t,processor)
};

int uname_main(int argc, char **argv)
{
	uname_info_t uname_info;
#if defined(__sparc__) && defined(__linux__)
	char *fake_sparc = getenv("FAKE_SPARC");
#endif
	const unsigned short int *delta;
	char toprint;

	toprint = bb_getopt_ulflags(argc, argv, options);

	if (argc != optind) {
		bb_show_usage();
	}

	if (toprint & (1 << 6)) {
		toprint = 0x3f;
	}

	if (toprint == 0) {
		toprint = 1;			/* sysname */
	}

	if (uname(&uname_info.name) == -1) {
		bb_error_msg_and_die("cannot get system name");
	}

#if defined(__sparc__) && defined(__linux__)
	if ((fake_sparc != NULL)
		&& ((fake_sparc[0] == 'y')
			|| (fake_sparc[0] == 'Y'))) {
		strcpy(uname_info.name.machine, "sparc");
	}
#endif

	strcpy(uname_info.processor, "unknown");

	delta=utsname_offset;
	do {
		if (toprint & 1) {
			bb_printf(((char *)(&uname_info)) + *delta);
			if (toprint > 1) {
				putchar(' ');
			}
		}
		++delta;
	} while (toprint >>= 1);
	putchar('\n');

	bb_fflush_stdout_and_exit(EXIT_SUCCESS);
}