управляющие символы (control characters)
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)
asa — interpret carriage-control characters
Синопсис (Synopsis)
asa [file...]
Описание (Description)
The asa utility shall write its input files to standard output,
mapping carriage-control characters from the text files to line-
printer control sequences in an implementation-defined manner.
The first character of every line shall be removed from the
input, and the following actions are performed.
If the character removed is:
<space> The rest of the line is output without change.
0 A <newline> is output, then the rest of the input line.
1 One or more implementation-defined characters that
causes an advance to the next page shall be output,
followed by the rest of the input line.
+ The <newline> of the previous line shall be replaced
with one or more implementation-defined characters that
causes printing to return to column position 1,
followed by the rest of the input line. If the '+' is
the first character in the input, it shall be
equivalent to <space>.
The action of the asa utility is unspecified upon encountering
any character other than those listed above as the first
character in a line.
Параметры (Options)
None.
Операнды (Operands)
file A pathname of a text file used for input. If no file
operands are specified, the standard input shall be
used.
Стандартный ввод (Stdin)
The standard input shall be used if no file operands are
specified, and shall be used if a file operand is '-' and the
implementation treats the '-' as meaning standard input.
Otherwise, the standard input shall not be used. See the INPUT
FILES section.
Входные файлы (Input files)
The input files shall be text files.
Переменные окружения (Environment variables)
The following environment variables shall affect the execution of
asa:
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 and input files).
LC_MESSAGES
Determine the locale that should be used to affect the
format and contents of diagnostic messages written to
standard error.
NLSPATH Determine the location of message catalogs for the
processing of LC_MESSAGES.
Асинхронные события (Asynchronous events)
Default.
Стандартный вывод (Stdout)
The standard output shall be the text from the input file
modified as described in the DESCRIPTION section.
Стандартный вывод сообщений (Stderr)
None.
Выходные файлы (Output files)
None.
Расширенное описание (Extended description)
None.
Статус выхода (Exit)
The following exit values shall be returned:
0 All input files were output successfully.
>0 An error occurred.
Последствия ошибок (Consequences of errors)
Default.
The following sections are informative.
Использование в приложениях (Application usage)
None.
Примеры (Examples)
1. The following command:
asa file
permits the viewing of file (created by a program using
FORTRAN-style carriage-control characters) on a terminal.
2. The following command:
a.out | asa | lp
formats the FORTRAN output of a.out and directs it to the
printer.
Обоснование (Rationale)
The asa utility is needed to map ``standard'' FORTRAN 77 output
into a form acceptable to contemporary printers. Usually, asa is
used to pipe data to the lp utility; see lp.
This utility is generally used only by FORTRAN programs. The
standard developers decided to retain asa to avoid breaking the
historical large base of FORTRAN applications that put carriage-
control characters in their output files. There is no requirement
that a system have a FORTRAN compiler in order to run
applications that need asa.
Historical implementations have used an ASCII <form-feed> in
response to a 1 and an ASCII <carriage-return> in response to a
'+'. It is suggested that implementations treat characters other
than 0, 1, and '+' as <space> in the absence of any compelling
reason to do otherwise. However, the action is listed here as
``unspecified'', permitting an implementation to provide
extensions to access fast multiple-line slewing and channel
seeking in a non-portable manner.
Будущие направления (Future directions)
None.
Смотри также (See also)
fort77(1p), lp(1p)
The Base Definitions volume of POSIX.1‐2017, Chapter 8,
Environment Variables
