UTMP(5) UTMP(5) NAME utmp, wtmp - login records SYNOPSIS #include DESCRIPTION The _u_t_m_p file records information about who is currently using the sys‐ tem. The file is a sequence of entries with the following structure declared in the include file: /* Copyright (C) 1993, 1996, 1997, 1998, 1999 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU Lesser General Public License as published by the Free Software Foundation; either version 2.1 of the License, or (at your option) any later version. The GNU C Library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more details. You should have received a copy of the GNU Lesser General Public License along with the GNU C Library; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA. */ #ifndef _UTMP_H #define _UTMP_H 1 #include #include __BEGIN_DECLS /* Get system dependent values and data structures. */ #include /* Compatibility names for the strings of the canonical file names. */ #define UTMP_FILE _PATH_UTMP #define UTMP_FILENAME _PATH_UTMP #define WTMP_FILE _PATH_WTMP #define WTMP_FILENAME _PATH_WTMP /* Make FD be the controlling terminal, stdin, stdout, and stderr; then close FD. Returns 0 on success, nonzero on error. */ extern int login_tty (int __fd) __THROW; /* Write the given entry into utmp and wtmp. */ extern void login (__const struct utmp *__entry) __THROW; /* Write the utmp entry to say the user on UT_LINE has logged out. */ extern int logout (__const char *__ut_line) __THROW; /* Append to wtmp an entry for the current time and the given info. */ extern void logwtmp (__const char *__ut_line, __const char *__ut_name, __const char *__ut_host) __THROW; /* Append entry UTMP to the wtmp-like file WTMP_FILE. */ extern void updwtmp (__const char *__wtmp_file, __const struct utmp *__utmp) __THROW; /* Change name of the utmp file to be examined. */ extern int utmpname (__const char *__file) __THROW; /* Read next entry from a utmp-like file. */ extern struct utmp *getutent (void) __THROW; /* Reset the input stream to the beginning of the file. */ extern void setutent (void) __THROW; /* Close the current open file. */ extern void endutent (void) __THROW; /* Search forward from the current point in the utmp file until the next entry with a ut_type matching ID->ut_type. */ extern struct utmp *getutid (__const struct utmp *__id) __THROW; /* Search forward from the current point in the utmp file until the next entry with a ut_line matching LINE->ut_line. */ extern struct utmp *getutline (__const struct utmp *__line) __THROW; /* Write out entry pointed to by UTMP_PTR into the utmp file. */ extern struct utmp *pututline (__const struct utmp *__utmp_ptr) __THROW; #ifdef __USE_MISC /* Reentrant versions of the file for handling utmp files. */ extern int getutent_r (struct utmp *__buffer, struct utmp **__result) __THROW; extern int getutid_r (__const struct utmp *__id, struct utmp *__buffer, struct utmp **__result) __THROW; extern int getutline_r (__const struct utmp *__line, struct utmp *__buffer, struct utmp **__result) __THROW; #endif /* Use misc. */ __END_DECLS #endif /* utmp.h */ This structure gives the name of the special file associated with the user’s terminal, the user’s login name, and the time of the login in the form of _t_i_m_e(3C). The _w_t_m_p file records all logins and logouts. A null user name indi‐ cates a logout on the associated terminal. Furthermore, the terminal name ‘~’ indicates that the system was rebooted at the indicated time; the adjacent pair of entries with terminal names ‘|’ and ‘{’ indicate the system-maintained time just before and just after a _d_a_t_e command has changed the system’s idea of the time. _W_t_m_p is maintained by _l_o_g_i_n(1) and _i_n_i_t(8). Neither of these programs creates the file, so if it is removed record-keeping is turned off. It is summarized by _a_c(8). FILES /etc/utmp /usr/adm/wtmp SEE ALSO login(1), init(8), who(1), ac(8) 4th Berkeley Distribution June 23, 1985 UTMP(5)