NAME

       endutxent, getutxent, getutxid, getutxline, pututxline, setutxent - user accounting database functions

SYNOPSIS

       #include <utmpx.h>

       void endutxent(void);
       struct utmpx *getutxent(void);
       struct utmpx *getutxid(const struct utmpx *id);
       struct utmpx *getutxline(const struct utmpx *line);
       struct utmpx *pututxline(const struct utmpx *utmpx);
       void setutxent(void);

DESCRIPTION

       These functions shall provide access to the user accounting database.

       The  getutxent() function shall read the next entry from the user accounting database. If the database is
       not already open, it shall open it. If it reaches the end of the database, it shall fail.

       The getutxid() function shall search forward from the current point in the database. If the ut_type value
       of  the  utmpx structure pointed to by id is BOOT_TIME, OLD_TIME, or NEW_TIME, then it shall stop when it
       finds an entry with a matching ut_type value.  If  the  ut_type  value  is  INIT_PROCESS,  LOGIN_PROCESS,
       USER_PROCESS,  or DEAD_PROCESS, then it shall stop when it finds an entry whose type is one of these four
       and whose ut_id member matches the ut_id member of the utmpx structure pointed to by id. If  the  end  of
       the database is reached without a match, getutxid() shall fail.

       The  getutxline()  function shall search forward from the current point in the database until it finds an
       entry of the type LOGIN_PROCESS or USER_PROCESS which also has a ut_line value matching that in the utmpx
       structure  pointed  to by line. If the end of the database is reached without a match, getutxline() shall
       fail.

       The getutxid() or getutxline() function may cache data.  For this reason, to use getutxline()  to  search
       for  multiple  occurrences,  the  application  shall  zero  out  the  static  data after each success, or
       getutxline() may return a pointer to the same utmpx structure.

       There is one exception to the rule about clearing the  structure  before  further  reads  are  done.  The
       implicit  read  done by pututxline() (if it finds that it is not already at the correct place in the user
       accounting database) shall not modify the  static  structure  returned  by  getutxent(),  getutxid(),  or
       getutxline(), if the application has modified this structure and passed the pointer back to pututxline().

       For  all  entries that match a request, the ut_type member indicates the type of the entry. Other members
       of the entry shall contain meaningful data based on the value of the ut_type member as follows:

                               ut_type Member   Other Members with Meaningful Data
                               EMPTY            No others
                               BOOT_TIME        ut_tv
                               OLD_TIME         ut_tv
                               NEW_TIME         ut_tv
                               USER_PROCESS     ut_id, ut_user (login name of the user),
                                                ut_line, ut_pid, ut_tv
                               INIT_PROCESS     ut_id, ut_pid, ut_tv
                               LOGIN_PROCESS    ut_id, ut_user (implementation-defined
                                                name of the login process), ut_pid,
                                                ut_tv
                               DEAD_PROCESS     ut_id, ut_pid, ut_tv

       An implementation that provides extended security controls may impose implementation-defined restrictions
       on accessing the user accounting database. In particular, the system may deny the existence  of  some  or
       all of the user accounting database entries associated with users other than the caller.

       If  the  process has appropriate privileges, the pututxline() function shall write out the structure into
       the user accounting database. It shall use getutxid() to search for a record that satisfies the  request.
       If  this  search  succeeds, then the entry shall be replaced. Otherwise, a new entry shall be made at the
       end of the user accounting database.

       The endutxent() function shall close the user accounting database.

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

       These functions need not be reentrant. A function that is not required to be reentrant is not required to
       be thread-safe.

RETURN VALUE

       Upon successful completion, getutxent(), getutxid(), and getutxline() shall return a pointer to  a  utmpx
       structure  containing  a  copy  of the requested entry in the user accounting database. Otherwise, a null
       pointer shall be returned.

       The return value may point to a static area which is overwritten by a subsequent call  to  getutxid()  or
       getutxline().

       Upon successful completion, pututxline() shall return a pointer to a utmpx structure containing a copy of
       the entry added to the user accounting database. Otherwise, a null pointer shall be returned.

       The endutxent() and setutxent() functions shall not return a value.

ERRORS

       No errors are defined  for  the  endutxent(),  getutxent(),  getutxid(),  getutxline(),  and  setutxent()
       functions.

       The pututxline() function may fail if:

       EPERM  The process does not have appropriate privileges.

       The following sections are informative.

EXAMPLES

       None.

APPLICATION USAGE

       The sizes of the arrays in the structure can be found using the sizeof operator.

RATIONALE

       None.

FUTURE DIRECTIONS

       None.

SEE ALSO

       The Base Definitions volume of IEEE Std 1003.1-2001, <utmpx.h>

COPYRIGHT

       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition,
       Standard for Information Technology -- Portable Operating System Interface (POSIX), The Open  Group  Base
       Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics Engineers,
       Inc and The Open Group. In the event of any discrepancy between this version and the  original  IEEE  and
       The  Open  Group  Standard,  the  original  IEEE and The Open Group Standard is the referee document. The
       original Standard can be obtained online at http://www.opengroup.org/unix/online.html .