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PROLOG | NAME | SYNOPSIS | DESCRIPTION | OPTIONS | OPERANDS | STDIN | INPUT FILES | ENVIRONMENT VARIABLES | ASYNCHRONOUS EVENTS | STDOUT | STDERR | OUTPUT FILES | EXTENDED DESCRIPTION | EXIT STATUS | CONSEQUENCES OF ERRORS | APPLICATION USAGE | EXAMPLES | RATIONALE | FUTURE DIRECTIONS | SEE ALSO | COPYRIGHT |
LOGGER(1P) POSIX Programmer's Manual LOGGER(1P)
This manual page is part of the POSIX Programmer's Manual. The Linux
implementation of this interface may differ (consult the
corresponding Linux manual page for details of Linux behavior), or
the interface may not be implemented on Linux.
logger — log messages
logger string...
The logger utility saves a message, in an unspecified manner and
format, containing the string operands provided by the user. The
messages are expected to be evaluated later by personnel performing
system administration tasks.
It is implementation-defined whether messages written in locales
other than the POSIX locale are effective.
None.
The following operand shall be supported:
string One of the string arguments whose contents are concatenated
together, in the order specified, separated by single
<space> characters.
Not used.
None.
The following environment variables shall affect the execution of
logger:
LANG Provide a default value for the internationalization
variables that are unset or null. (See the Base Definitions
volume of POSIX.1‐2008, Section 8.2, Internationalization
Variables for the precedence of internationalization
variables used to determine the values of locale
categories.)
LC_ALL If set to a non-empty string value, override the values of
all the other internationalization variables.
LC_CTYPE Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte
as opposed to multi-byte characters in arguments).
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error. (This means diagnostics from logger to the
user or application, not diagnostic messages that the user
is sending to the system administrator.)
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
Default.
Not used.
The standard error shall be used only for diagnostic messages.
Unspecified.
None.
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
Default.
The following sections are informative.
This utility allows logging of information for later use by a system
administrator or programmer in determining why non-interactive
utilities have failed. The locations of the saved messages, their
format, and retention period are all unspecified. There is no method
for a conforming application to read messages, once written.
A batch application, running non-interactively, tries to read a
configuration file and fails; it may attempt to notify the system
administrator with:
logger myname: unable to read file foo. [timestamp]
The standard developers believed strongly that some method of
alerting administrators to errors was necessary. The obvious example
is a batch utility, running non-interactively, that is unable to read
its configuration files or that is unable to create or write its
results file. However, the standard developers did not wish to define
the format or delivery mechanisms as they have historically been (and
will probably continue to be) very system-specific, as well as
involving functionality clearly outside the scope of this volume of
POSIX.1‐2008.
The text with LC_MESSAGES about diagnostic messages means diagnostics
from logger to the user or application, not diagnostic messages that
the user is sending to the system administrator.
Multiple string arguments are allowed, similar to echo, for ease-of-
use.
Like the utilities mailx and lp, logger is admittedly difficult to
test. This was not deemed sufficient justification to exclude these
utilities from this volume of POSIX.1‐2008. It is also arguable that
they are, in fact, testable, but that the tests themselves are not
portable.
None.
lp(1p), mailx(1p), write(1p)
The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
Variables
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2013 Edition, Standard for Information
Technology -- Portable Operating System Interface (POSIX), The Open
Group Base Specifications Issue 7, Copyright (C) 2013 by the
Institute of Electrical and Electronics Engineers, Inc and The Open
Group. (This is POSIX.1-2008 with the 2013 Technical Corrigendum 1
applied.) 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.unix.org/online.html .
Any typographical or formatting errors that appear in this page are
most likely to have been introduced during the conversion of the
source files to man page format. To report such errors, see
https://www.kernel.org/doc/man-pages/reporting_bugs.html .
IEEE/The Open Group 2013 LOGGER(1P)