1ENDUTXENT(3P) POSIX Programmer's Manual ENDUTXENT(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
12 endutxent, getutxent, getutxid, getutxline, pututxline, setutxent —
13 user accounting database functions
14
16 #include <utmpx.h>
17 void endutxent(void);
19 struct utmpx *getutxent(void);
20 struct utmpx *getutxid(const struct utmpx *id);
21 struct utmpx *getutxline(const struct utmpx *line);
22 struct utmpx *pututxline(const struct utmpx *utmpx);
23 void setutxent(void);
24
26 These functions shall provide access to the user accounting database.
27 The getutxent() function shall read the next entry from the user
29 accounting database. If the database is not already open, it shall
30 open it. If it reaches the end of the database, it shall fail.
31 The getutxid() function shall search forward from the current point in
33 the database. If the ut_type value of the utmpx structure pointed to
34 by id is BOOT_TIME, OLD_TIME, or NEW_TIME, then it shall stop when it
35 finds an entry with a matching ut_type value. If the ut_type value is
36 INIT_PROCESS, LOGIN_PROCESS, USER_PROCESS, or DEAD_PROCESS, then it
37 shall stop when it finds an entry whose type is one of these four and
38 whose ut_id member matches the ut_id member of the utmpx structure
39 pointed to by id. If the end of the database is reached without a
40 match, getutxid() shall fail.
41 The getutxline() function shall search forward from the current point
43 in the database until it finds an entry of the type LOGIN_PROCESS or
44 USER_PROCESS which also has a ut_line value matching that in the utmpx
45 structure pointed to by line. If the end of the database is reached
46 without a match, getutxline() shall fail.
47 The getutxid() or getutxline() function may cache data. For this rea‐
49 son, to use getutxline() to search for multiple occurrences, the appli‐
50 cation shall zero out the static data after each success, or getutx‐
51 line() may return a pointer to the same utmpx structure.
52 There is one exception to the rule about clearing the structure before
54 further reads are done. The implicit read done by pututxline() (if it
55 finds that it is not already at the correct place in the user account‐
56 ing database) shall not modify the static structure returned by getutx‐
57 ent(), getutxid(), or getutxline(), if the application has modified
58 this structure and passed the pointer back to pututxline().
59 For all entries that match a request, the ut_type member indicates the
61 type of the entry. Other members of the entry shall contain meaningful
62 data based on the value of the ut_type member as follows:
63 ┌───────────────┬─────────────────────────────────────────────────────────────────┐
65 │ut_type Member │ Other Members with Meaningful Data │
66 ├───────────────┼─────────────────────────────────────────────────────────────────┤
67 │EMPTY │ No others │
68 │BOOT_TIME │ ut_tv │
69 │OLD_TIME │ ut_tv │
70 │NEW_TIME │ ut_tv │
71 │USER_PROCESS │ ut_id, ut_user (login name of the user), ut_line, ut_pid, ut_tv │
72 │INIT_PROCESS │ ut_id, ut_pid, ut_tv │
73 │LOGIN_PROCESS │ ut_id, ut_user (implementation-defined name of the login │
74 │ │ process), ut_line, ut_pid, ut_tv │
75 │DEAD_PROCESS │ ut_id, ut_pid, ut_tv │
76 └───────────────┴─────────────────────────────────────────────────────────────────┘
77 An implementation that provides extended security controls may impose
78 implementation-defined restrictions on accessing the user accounting
79 database. In particular, the system may deny the existence of some or
80 all of the user accounting database entries associated with users other
81 than the caller.
82 If the process has appropriate privileges, the pututxline() function
84 shall write out the structure into the user accounting database. It
85 shall search for a record as if by getutxid() that satisfies the
86 request. If this search succeeds, then the entry shall be replaced.
87 Otherwise, a new entry shall be made at the end of the user accounting
88 database.
89 The endutxent() function shall close the user accounting database.
91 The setutxent() function shall reset the input to the beginning of the
93 database. This should be done before each search for a new entry if it
94 is desired that the entire database be examined.
95 These functions need not be thread-safe.
97
99 Upon successful completion, getutxent(), getutxid(), and getutxline()
100 shall return a pointer to a utmpx structure containing a copy of the
101 requested entry in the user accounting database. Otherwise, a null
102 pointer shall be returned.
103 The return value may point to a static area which is overwritten by a
105 subsequent call to getutxid() or getutxline().
106 Upon successful completion, pututxline() shall return a pointer to a
108 utmpx structure containing a copy of the entry added to the user
109 accounting database. Otherwise, a null pointer shall be returned.
110 The endutxent() and setutxent() functions shall not return a value.
112
114 No errors are defined for the endutxent(), getutxent(), getutxid(),
115 getutxline(), and setutxent() functions.
116 The pututxline() function may fail if:
118 EPERM The process does not have appropriate privileges.
120 The following sections are informative.
122
124 None.
125
127 The sizes of the arrays in the structure can be found using the sizeof
128 operator.
129
131 None.
132
134 None.
135
137 The Base Definitions volume of POSIX.1‐2017, <utmpx.h>
138
140 Portions of this text are reprinted and reproduced in electronic form
141 from IEEE Std 1003.1-2017, Standard for Information Technology -- Por‐
142 table Operating System Interface (POSIX), The Open Group Base Specifi‐
143 cations Issue 7, 2018 Edition, Copyright (C) 2018 by the Institute of
144 Electrical and Electronics Engineers, Inc and The Open Group. In the
145 event of any discrepancy between this version and the original IEEE and
146 The Open Group Standard, the original IEEE and The Open Group Standard
147 is the referee document. The original Standard can be obtained online
148 at http://www.opengroup.org/unix/online.html .
149 Any typographical or formatting errors that appear in this page are
151 most likely to have been introduced during the conversion of the source
152 files to man page format. To report such errors, see https://www.ker‐
153 nel.org/doc/man-pages/reporting_bugs.html .
154IEEE/The Open Group 2017 ENDUTXENT(3P)