getutent

NAME

       getutent,  getutid,  getutline, pututline, setutent, endu-
       tent, utmpname - access utmp file entries

SYNOPSIS

       #include <utmp.h>

       struct utmp *getutent(void);
       struct utmp *getutid(struct utmp *ut);
       struct utmp *getutline(struct utmp *ut);

       void pututline(struct utmp *ut);

       void setutent(void);
       void endutent(void);

       void utmpname(const char *file);

DESCRIPTION

       utmpname() sets the name of the utmp-format file  for  the
       other utmp functions to access.  If utmpname() is not used
       to set the filename before the other functions  are  used,
       they assume _PATH_UTMP, as defined in <paths.h>.

       setutent()  rewinds  the  file pointer to the beginning of
       the utmp file.  It is generally a Good  Idea  to  call  it
       before any of the other functions.

       endutent() closes the utmp file.  It should be called when
       the user code is done accessing the file  with  the  other
       functions.

       getutent()  reads a line from the current file position in
       the utmp file.  It returns a pointer to a  structure  con-
       taining the fields of the line.

       getutid()  searches forward from the current file position
       in the  utmp  file  based  upon  ut.   If  ut->ut_type  is
       RUN_LVL,  BOOT_TIME, NEW_TIME, or OLD_TIME, getutid() will
       find  the  first  entry  whose   ut_type   field   matches
       ut->ut_type.   If  ut->ut_type is INIT_PROCESS, LOGIN_PRO-
       CESS, USER_PROCESS, or DEAD_PROCESS, getutid()  will  find
       the first entry whose ut_id field matches ut->ut_id.

       getutline()  searches  forward from the current file posi-
       tion in the utmp file.  It scans entries whose ut_type  is
       USER_PROCESS  or  LOGIN_PROCESS  and returns the first one
       whose ut_line field matches ut->ut_line.

       pututline() writes the utmp structure  ut  into  the  utmp
       file.  It uses getutid() to search for the proper place in
       the file to insert the new entry.  If it  cannot  find  an
       appropriate  slot  for ut, pututline() will append the new
       entry to the end of the file.

RETURN VALUE

       getutent(), getutid(), and getutline() return a pointer to
       a struct utmp, which is defined in <utmp.h>.

FILES

       /var/run/utmp - database of currently logged-in users
       /var/log/wtmp - database of past user logins

CONFORMING TO

       XPG 2, SVID 2, Linux FSSTND 1.2

SEE ALSO

       utmp(5)