blob: 10b9615a1e86fad3e54fe8e6765ee8b396f7309c
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 | |
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 | //usage:#define logname_trivial_usage |
24 | //usage: "" |
25 | //usage:#define logname_full_usage "\n\n" |
26 | //usage: "Print the name of the current user" |
27 | //usage: |
28 | //usage:#define logname_example_usage |
29 | //usage: "$ logname\n" |
30 | //usage: "root\n" |
31 | |
32 | #include "libbb.h" |
33 | |
34 | /* This is a NOFORK applet. Be very careful! */ |
35 | |
36 | int logname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; |
37 | int logname_main(int argc UNUSED_PARAM, char **argv UNUSED_PARAM) |
38 | { |
39 | char buf[64]; |
40 | |
41 | if (argv[1]) { |
42 | bb_show_usage(); |
43 | } |
44 | |
45 | /* Using _r function - avoid pulling in static buffer from libc */ |
46 | if (getlogin_r(buf, sizeof(buf)) == 0) { |
47 | puts(buf); |
48 | return fflush_all(); |
49 | } |
50 | |
51 | bb_perror_msg_and_die("getlogin"); |
52 | } |
53 |