blob: a9b1c956dd470e0d3a25180a362ec6eb5d1b1608
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 source tree. |
8 | */ |
9 | /* Mar 16, 2003 Manuel Novoa III (mjn3@codepoet.org) |
10 | * |
11 | * SUSv3 specifies the string used is that returned from getlogin(). |
12 | * The previous implementation used getpwuid() for geteuid(), which |
13 | * is _not_ the same. Erik apparently made this change almost 3 years |
14 | * ago to avoid failing when no utmp was available. However, the |
15 | * correct course of action wrt SUSv3 for a failing getlogin() is |
16 | * a diagnostic message and an error return. |
17 | */ |
18 | //config:config LOGNAME |
19 | //config: bool "logname" |
20 | //config: default y |
21 | //config: help |
22 | //config: logname is used to print the current user's login name. |
23 | |
24 | //applet:IF_LOGNAME(APPLET_NOFORK(logname, logname, BB_DIR_USR_BIN, BB_SUID_DROP, logname)) |
25 | |
26 | //kbuild:lib-$(CONFIG_LOGNAME) += logname.o |
27 | |
28 | /* BB_AUDIT SUSv3 compliant */ |
29 | /* http://www.opengroup.org/onlinepubs/007904975/utilities/logname.html */ |
30 | |
31 | //usage:#define logname_trivial_usage |
32 | //usage: "" |
33 | //usage:#define logname_full_usage "\n\n" |
34 | //usage: "Print the name of the current user" |
35 | //usage: |
36 | //usage:#define logname_example_usage |
37 | //usage: "$ logname\n" |
38 | //usage: "root\n" |
39 | |
40 | #include "libbb.h" |
41 | |
42 | /* This is a NOFORK applet. Be very careful! */ |
43 | |
44 | int logname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
45 | int logname_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) |
46 | { |
47 | char buf[64]; |
48 | |
49 | if (argv[1]) { |
50 | bb_show_usage(); |
51 | } |
52 | |
53 | /* Using _r function - avoid pulling in static buffer from libc */ |
54 | if (getlogin_r(buf, sizeof(buf)) == 0) { |
55 | puts(buf); |
56 | return fflush_all(); |
57 | } |
58 | |
59 | bb_perror_msg_and_die("getlogin"); |
60 | } |
61 |