busybox/coreutils/logname.c

/* vi: set sw=4 ts=4: */
/*
 * Mini logname implementation for busybox
 *
 * Copyright (C) 2000  Edward Betts <edward@debian.org>.
 *
 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
 */

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

/* Mar 16, 2003      Manuel Novoa III   (mjn3@codepoet.org)
 *
 * SUSv3 specifies the string used is that returned from getlogin().
 * The previous implementation used getpwuid() for geteuid(), which
 * is _not_ the same.  Erik apparently made this change almost 3 years
 * ago to avoid failing when no utmp was available.  However, the
 * correct course of action wrt SUSv3 for a failing getlogin() is
 * a diagnostic message and an error return.
 */

#include "libbb.h"

/* This is a NOFORK applet. Be very careful! */

int logname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int logname_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
{
	char buf[64];

	if (argv[1]) {
		bb_show_usage();
	}

	/* Using _r function - avoid pulling in static buffer from libc */
	if (getlogin_r(buf, sizeof(buf)) == 0) {
		puts(buf);
		return fflush_all();
	}

	bb_perror_msg_and_die("getlogin");
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Mini logname implementation for busybox
4	*
5	* Copyright (C) 2000 Edward Betts <edward@debian.org>.
6	*
7	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8	*/
9
10	/* BB_AUDIT SUSv3 compliant */
11	/* http://www.opengroup.org/onlinepubs/007904975/utilities/logname.html */
12
13	/* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org)
14	*
15	* SUSv3 specifies the string used is that returned from getlogin().
16	* The previous implementation used getpwuid() for geteuid(), which
17	* is _not_ the same. Erik apparently made this change almost 3 years
18	* ago to avoid failing when no utmp was available. However, the
19	* correct course of action wrt SUSv3 for a failing getlogin() is
20	* a diagnostic message and an error return.
21	*/
22
23	#include "libbb.h"
24
25	/* This is a NOFORK applet. Be very careful! */
26
27	int logname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
28	int logname_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM)
29	{
30	char buf[64];
31
32	if (argv[1]) {
33	bb_show_usage();
34	}
35
36	/* Using _r function - avoid pulling in static buffer from libc */
37	if (getlogin_r(buf, sizeof(buf)) == 0) {
38	puts(buf);
39	return fflush_all();
40	}
41
42	bb_perror_msg_and_die("getlogin");
43	}