getutent(3C)						   Standard C Library Functions 					      getutent(3C)

NAME

       getutent, getutid, getutline, pututline, setutent, endutent, utmpname - user accounting database functions

SYNOPSIS

       #include <utmp.h>

       struct utmp *getutent(void);

       struct utmp *getutid(const struct utmp *id);

       struct utmp *getutline(const struct utmp *line);

       struct utmp *pututline(const struct utmp *utmp);

       void setutent(void);

       void endutent(void);

       int utmpname(const char *file);

DESCRIPTION

       These  functions  provide  access  to the user accounting database, utmp. Entries in the database are described by the definitions and data
       structures in <utmp.h>.

       The utmp structure contains the following members:

       char		   ut_user[8];	 /* user login name */
       char		   ut_id[4];	 /* /sbin/inittab id (usually line #) */
       char		   ut_line[12];  /* device name (console, lnxx) */
       short		   ut_pid;	 /* process id */
       short		   ut_type;	 /* type of entry */
       struct exit_status  ut_exit;	 /* exit status of a process */
					 /* marked as DEAD_PROCESS */
       time_t		   ut_time;	 /* time entry was made */

       The structure exit_status includes the following members:

       short   e_termination;	/* termination status */
       short   e_exit;		/* exit status */

   getutent()
       The getutent() function reads in the next entry from a utmp database.  If the database is not already open, it opens it.  If it reaches the
       end of the database, it fails.

   getutid()
       The  getutid()  function  searches  forward  from  the  current	point in the utmp database until it finds an entry with a ut_type matching
       id->ut_type if the type specified is RUN_LVL, BOOT_TIME, DOWN_TIME, OLD_TIME, or NEW_TIME. If the type specified  in  id  is  INIT_PROCESS,
       LOGIN_PROCESS,  USER_PROCESS,  or DEAD_PROCESS, then getutid() will return a pointer to the first entry whose type is one of these four and
       whose ut_id member matches id->ut_id. If the end of database is reached without a match, it fails.

   getutline()
       The getutline() function searches forward from the current point in the utmp database until it finds an entry of the type LOGIN_PROCESS	or
       ut_line string matching the line->ut_line string.  If the end of database is reached without a match, it fails.

   pututline()
       The  pututline()  function  writes  the supplied utmp structure into the utmp database.	It uses getutid() to search forward for the proper
       place if it finds that it is not already at the proper place.  It is expected that normally the user of pututline() will have searched  for
       the  proper  entry using one of the these functions.  If so, pututline() will not search.  If pututline() does not find a matching slot for
       the new entry, it will add a new entry to the end of the database.
	It returns a pointer to the utmp structure. When called by a non-root user, pututline() invokes a setuid()  root  program  to  verify  and
       write  the  entry,  since  the  utmp  database is normally writable only by root.  In this event, the ut_name member must correspond to the
       actual user name associated with the process; the  ut_type member must be either USER_PROCESS or DEAD_PROCESS; and the ut_line member  must
       be a device special file and be writable by the user.

   setutent()
       The  setutent()	function  resets the input stream to the beginning.  This reset should be done before each search for a new entry if it is
       desired that the entire database be examined.

   endutent()
       The endutent() function closes the currently open database.

   utmpname()
       The utmpname() function allows the user to change the name of the database file examined to another file.  If the file does not exist, this
       will  not be apparent until the first attempt to reference the file is made.  The utmpname() function does not open the file but closes the
       old file if it is currently open and saves the new file name.

RETURN VALUES

       A null pointer is returned upon failure to read, whether for permissions or having reached the end of file, or upon failure  to	write.	If
       the file name given is longer than 79 characters, utmpname() returns 0.	Otherwise, it returns 1.

USAGE

       These functions use buffered standard I/O for input, but pututline() uses an unbuffered non-standard write to avoid race conditions between
       processes trying to modify the utmp and wtmp databases.

       Applications should not access the utmp and wtmp databases directly, but should use these functions to  ensure  that  these  databases  are
       maintained consistently. Using these functions, however, may cause applications to fail if user accounting data cannot be represented prop-
       erly in the utmp structure (for example, on a system where PIDs can exceed 32767).  Use the functions described on the getutxent(3C) manual
       page instead.

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |MT-Level		     |Unsafe			   |
       +-----------------------------+-----------------------------+

SEE ALSO

       getutxent(3C), ttyslot(3C), utmpx(4), attributes(5)

NOTES

       The  most  current  entry is saved in a static structure.  Multiple accesses require that it be copied before further accesses are made. On
       each call to either getutid() or getutline(), the function examines the static structure before performing more I/O.  If  the  contents	of
       the  static  structure  match  what  it	is searching for, it looks no further.	For this reason, to use getutline() to search for multiple
       occurrences, it would be necessary to zero out the static area after each success, or getutline() would just return the same structure over
       and  over  again. There is one exception to the rule about emptying the structure before further reads are done.  The implicit read done by
       pututline() (if it finds that it is not already at the correct place in the file) will not  hurt  the  contents	of  the  static  structure
       returned by the getutent(), getutid() or getutline() functions, if the user has just modified those contents and passed the pointer back to
       pututline().

SunOS 5.10							    27 Oct 1998 						      getutent(3C)