1getutent(3)                Library Functions Manual                getutent(3)
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NAME

6       getutent, getutid, getutline, pututline, setutent, endutent, utmpname -
7       access utmp file entries
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LIBRARY

10       Standard C library (libc, -lc)
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SYNOPSIS

13       #include <utmp.h>
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15       struct utmp *getutent(void);
16       struct utmp *getutid(const struct utmp *ut);
17       struct utmp *getutline(const struct utmp *ut);
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19       struct utmp *pututline(const struct utmp *ut);
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21       void setutent(void);
22       void endutent(void);
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24       int utmpname(const char *file);
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DESCRIPTION

27       New applications should use the POSIX.1-specified "utmpx"  versions  of
28       these functions; see STANDARDS.
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30       utmpname()  sets  the  name  of the utmp-format file for the other utmp
31       functions to access.  If utmpname() is not used to set the filename be‐
32       fore  the  other functions are used, they assume _PATH_UTMP, as defined
33       in <paths.h>.
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35       setutent() rewinds the file pointer to the beginning of the utmp  file.
36       It  is  generally  a good idea to call it before any of the other func‐
37       tions.
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39       endutent() closes the utmp file.  It should be  called  when  the  user
40       code is done accessing the file with the other functions.
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42       getutent()  reads  a  line  from  the current file position in the utmp
43       file.  It returns a pointer to a structure containing the fields of the
44       line.  The definition of this structure is shown in utmp(5).
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46       getutid()  searches  forward from the current file position in the utmp
47       file based upon ut.  If  ut->ut_type  is  one  of  RUN_LVL,  BOOT_TIME,
48       NEW_TIME,  or  OLD_TIME,  getutid()  will  find  the  first entry whose
49       ut_type  field  matches  ut->ut_type.   If  ut->ut_type   is   one   of
50       INIT_PROCESS,  LOGIN_PROCESS,  USER_PROCESS, or DEAD_PROCESS, getutid()
51       will find the first entry whose ut_id field matches ut->ut_id.
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53       getutline() searches forward from the current file position in the utmp
54       file.   It scans entries whose ut_type is USER_PROCESS or LOGIN_PROCESS
55       and returns the first one whose ut_line field matches ut->ut_line.
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57       pututline() writes the utmp structure ut into the utmp file.   It  uses
58       getutid()  to search for the proper place in the file to insert the new
59       entry.  If it cannot find an appropriate slot for ut, pututline()  will
60       append the new entry to the end of the file.
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RETURN VALUE

63       getutent(),  getutid(),  and  getutline()  return a pointer to a struct
64       utmp on success, and NULL on failure (which includes  the  "record  not
65       found" case).  This struct utmp is allocated in static storage, and may
66       be overwritten by subsequent calls.
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68       On success pututline() returns ut; on failure, it returns NULL.
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70       utmpname() returns 0 if the new name was successfully stored, or -1  on
71       failure.
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73       On failure, these functions errno set to indicate the error.
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ERRORS