сообщения журнала (log messages)
Пролог (Prolog)
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.
Имя (Name)
logger — log messages
Синопсис (Synopsis)
logger string...
Описание (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.
Параметры (Options)
None.
Операнды (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> characters.
Стандартный ввод (Stdin)
Not used.
Входные файлы (Input files)
None.
Переменные окружения (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 POSIX.1‐2017, 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.
Асинхронные события (Asynchronous events)
Default.
Стандартный вывод (Stdout)
Not used.
Стандартный вывод сообщений (Stderr)
The standard error shall be used only for diagnostic messages.
Выходные файлы (Output files)
Unspecified.
Расширенное описание (Extended description)
None.
Статус выхода (Exit)
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
Последствия ошибок (Consequences of errors)
Default.
The following sections are informative.
Использование в приложениях (Application usage)
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.
Примеры (Examples)
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]
Обоснование (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
POSIX.1‐2017.
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.1‐2017. It is also
arguable that they are, in fact, testable, but that the tests
themselves are not portable.
Будущие направления (Future directions)
None.
Смотри также (See also)
lp(1p), mailx(1p), write(1p)
The Base Definitions volume of POSIX.1‐2017, Chapter 8,
Environment Variables
