getut(3G)                                                  getut(3G)


       NAME
             getut: getutent, getutid, getutline, pututline, setutent,
             endutent, utmpname - access utmp file entry

       SYNOPSIS
             cc [flag . . . ] file . . . -lgen [library] . . .
             #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
             getutent, getutid, getutline, and pututline each return a
             pointer to a utmp structure.  [See utmp(4)].

             getutent reads in the next entry from a utmp-like file.  If
             the file is not already open, it opens it.  If it reaches the
             end of the file, it fails.

             getutid searches forward from the current point in the utmp
             file until it finds an entry with a ut_type matching id-
             >ut_type if the type specified is RUN_LVL, BOOT_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 field matches id-
             >ut_id .  If the end of file is reached without a match, it
             fails.

             getutline searches forward from the current point in the utmp
             file until it finds an entry of the type LOGIN_PROCESS or
             USER_PROCESS that also has a ut_line string matching the
             line->ut_line string.  If the end of file is reached without a
             match, it fails.

             pututline writes out the supplied utmp structure into the utmp
             file.  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 getut routines.
             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


                           Copyright 1994 Novell, Inc.               Page 1

      getut(3G)                                                  getut(3G)


            the end of the file.  It returns a pointer to the utmp
            structure.

            setutent resets the input stream to the beginning of the file.
            This reset should be done before each search for a new entry
            if it is desired that the entire file be examined.

            endutent closes the currently open file.

            utmpname allows the user to change the name of the file
            examined, from /var/adm/utmp to any other file.  It is most
            often expected that this other file will be /var/adm/wtmp.  If
            the file does not exist, this will not be apparent until the
            first attempt to reference the file is made.  utmpname does
            not open the file.  It just closes the old file if it is
            currently open and saves the new file name.  If the file name
            given is longer than 79 characters, utmpname returns 0.
            Otherwise, it will return 1.

         Files
            /var/adm/utmp
            /var/adm/wtmp

         Errors
            A null pointer is returned upon failure to read, whether for
            permissions or having reached the end of file, or upon failure
            to write.

      REFERENCES
            getutx(3G), ttyslot(3C), utmp(4)

      NOTICES
            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 routine 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,


                          Copyright 1994 Novell, Inc.               Page 2

       getut(3G)                                                  getut(3G)


             getutid or getutline routines, if the user has just modified
             those contents and passed the pointer back to pututline.

             These routines 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 files.









































                           Copyright 1994 Novell, Inc.               Page 3