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)

PROLOG         top

       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.

NAME         top

       logger — log messages

SYNOPSIS         top

       logger string...

DESCRIPTION         top

       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.

OPTIONS         top

       None.

OPERANDS         top

       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.

STDIN         top

       Not used.

INPUT FILES         top

       None.

ENVIRONMENT VARIABLES         top

       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.

ASYNCHRONOUS EVENTS         top

       Default.

STDOUT         top

       Not used.

STDERR         top

       The standard error shall be used only for diagnostic messages.

OUTPUT FILES         top

       Unspecified.

EXTENDED DESCRIPTION         top

       None.

EXIT STATUS         top

       The following exit values shall be returned:

        0    Successful completion.

       >0    An error occurred.

CONSEQUENCES OF ERRORS         top

       Default.

       The following sections are informative.

APPLICATION USAGE         top

       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.

EXAMPLES         top

       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]

RATIONALE         top

       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.

FUTURE DIRECTIONS         top

       None.

SEE ALSO         top

       lp(1p), mailx(1p), write(1p)

       The Base Definitions volume of POSIX.1‐2008, Chapter 8, Environment
       Variables

COPYRIGHT         top

       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)