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 (1.1 kb)" 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 44int logname_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE; 45int 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