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 |