1LOGGER(1P) POSIX Programmer's Manual LOGGER(1P)
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 logger - log messages
13
15 logger string ...
16
18 The logger utility saves a message, in an unspecified manner and for‐
19 mat, containing the string operands provided by the user. The messages
20 are expected to be evaluated later by personnel performing system
21 administration tasks.
22 It is implementation-defined whether messages written in locales other
24 than the POSIX locale are effective.
25
27 None.
28
30 The following operand shall be supported:
31 string One of the string arguments whose contents are concatenated
33 together, in the order specified, separated by single <space>s.
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37 Not used.
38
40 None.
41
43 The following environment variables shall affect the execution of log‐
44 ger:
45 LANG Provide a default value for the internationalization variables
47 that are unset or null. (See the Base Definitions volume of
48 IEEE Std 1003.1-2001, Section 8.2, Internationalization Vari‐
49 ables for the precedence of internationalization variables used
50 to determine the values of locale categories.)
51 LC_ALL If set to a non-empty string value, override the values of all
53 the other internationalization variables.
54 LC_CTYPE
56 Determine the locale for the interpretation of sequences of
57 bytes of text data as characters (for example, single-byte as
58 opposed to multi-byte characters in arguments).
59 LC_MESSAGES
61 Determine the locale that should be used to affect the format
62 and contents of diagnostic messages written to standard error.
63 (This means diagnostics from logger to the user or application,
64 not diagnostic messages that the user is sending to the system
65 administrator.)
66 NLSPATH
68 Determine the location of message catalogs for the processing of
69 LC_MESSAGES .
70
73 Default.
74
76 Not used.
77
79 The standard error shall be used only for diagnostic messages.
80
82 Unspecified.
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85 None.
86
88 The following exit values shall be returned:
89 0 Successful completion.
91 >0 An error occurred.
93
96 Default.
97 The following sections are informative.
99
101 This utility allows logging of information for later use by a system
102 administrator or programmer in determining why non-interactive utili‐
103 ties have failed. The locations of the saved messages, their format,
104 and retention period are all unspecified. There is no method for a
105 conforming application to read messages, once written.
106
108 A batch application, running non-interactively, tries to read a config‐
109 uration file and fails; it may attempt to notify the system administra‐
110 tor with:
111 logger myname: unable to read file foo. [timestamp]
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116 The standard developers believed strongly that some method of alerting
117 administrators to errors was necessary. The obvious example is a batch
118 utility, running non-interactively, that is unable to read its configu‐
119 ration files or that is unable to create or write its results file.
120 However, the standard developers did not wish to define the format or
121 delivery mechanisms as they have historically been (and will probably
122 continue to be) very system-specific, as well as involving functional‐
123 ity clearly outside the scope of this volume of IEEE Std 1003.1-2001.
124 The text with LC_MESSAGES about diagnostic messages means diagnostics
126 from logger to the user or application, not diagnostic messages that
127 the user is sending to the system administrator.
128 Multiple string arguments are allowed, similar to echo, for ease-of-
130 use.
131 Like the utilities mailx and lp, logger is admittedly difficult to
133 test. This was not deemed sufficient justification to exclude these
134 utilities from this volume of IEEE Std 1003.1-2001. It is also arguable
135 that they are, in fact, testable, but that the tests themselves are not
136 portable.
137
139 None.
140
142 lp, mailx, write()
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145 Portions of this text are reprinted and reproduced in electronic form
146 from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
147 -- Portable Operating System Interface (POSIX), The Open Group Base
148 Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
149 Electrical and Electronics Engineers, Inc and The Open Group. In the
150 event of any discrepancy between this version and the original IEEE and
151 The Open Group Standard, the original IEEE and The Open Group Standard
152 is the referee document. The original Standard can be obtained online
153 at http://www.opengroup.org/unix/online.html .
154IEEE/The Open Group 2003 LOGGER(1P)