centos man page for logger

LOGGER(1P)						     POSIX Programmer's Manual							LOGGER(1P)

PROLOG
       This  manual page is part of the POSIX Programmer's Manual.  The Linux implementation of this interface may differ (consult the correspond-
       ing Linux manual page for details of Linux behavior), or the interface may not be implemented on Linux.

NAME
       logger - log messages

SYNOPSIS
       logger string ...

DESCRIPTION
       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
       None.

OPERANDS
       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>s.

STDIN
       Not used.

INPUT FILES
       None.

ENVIRONMENT VARIABLES
       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
	      IEEE Std 1003.1-2001, 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 administra-
	      tor.)

       NLSPATH
	      Determine the location of message catalogs for the processing of LC_MESSAGES .

ASYNCHRONOUS EVENTS
       Default.

STDOUT
       Not used.

STDERR
       The standard error shall be used only for diagnostic messages.

OUTPUT FILES
       Unspecified.

EXTENDED DESCRIPTION
       None.

EXIT STATUS
       The following exit values shall be returned:

	0     Successful completion.

       >0     An error occurred.

CONSEQUENCES OF ERRORS
       Default.

       The following sections are informative.

APPLICATION USAGE
       This utility allows logging of information for later use by a system administrator or programmer in determining why non-interactive  utili-
       ties  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
       A batch application, running non-interactively, tries to read a configuration file and fails; it may attempt to notify the system  adminis-
       trator with:

	      logger myname: unable to read file foo. [timestamp]

RATIONALE
       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
       IEEE Std 1003.1-2001.

       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 IEEE Std 1003.1-2001. It is also arguable that they are, in fact, testable, but that the tests themselves are
       not portable.

FUTURE DIRECTIONS
       None.

SEE ALSO
       lp, mailx, write()

COPYRIGHT
       Portions of this text are reprinted and reproduced in electronic form from IEEE Std 1003.1, 2003 Edition, Standard for Information Technol-
       ogy -- Portable Operating System Interface (POSIX), The Open Group Base Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
       Electrical and Electronics Engineers, Inc and The Open Group. 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.opengroup.org/unix/online.html .

IEEE
/The Open Group						       2003								LOGGER(1P)