сдвиг позиционных параметров (shift positional parameters)
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)
shift — shift positional parameters
Синопсис (Synopsis)
shift [
n]
Описание (Description)
The positional parameters shall be shifted. Positional parameter
1 shall be assigned the value of parameter (1+n), parameter 2
shall be assigned the value of parameter (2+n), and so on. The
parameters represented by the numbers "$#"
down to "$#-n+1"
shall
be unset, and the parameter '#'
is updated to reflect the new
number of positional parameters.
The value n shall be an unsigned decimal integer less than or
equal to the value of the special parameter '#'
. If n is not
given, it shall be assumed to be 1. If n is 0, the positional and
special parameters are not changed.
Параметры (Options)
None.
Операнды (Operands)
See the DESCRIPTION.
Стандартный ввод (Stdin)
Not used.
Входные файлы (Input files)
None.
Переменные окружения (Environment variables)
None.
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)
None.
Расширенное описание (Extended description)
None.
Статус выхода (Exit)
If the n operand is invalid or is greater than "$#"
, this may be
considered a syntax error and a non-interactive shell may exit;
if the shell does not exit in this case, a non-zero exit status
shall be returned. Otherwise, zero shall be returned.
Последствия ошибок (Consequences of errors)
Default.
The following sections are informative.
Использование в приложениях (Application usage)
None.
Примеры (Examples)
$
set a b c d e
$
shift 2
$
echo $*
c d e
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
Section 2.14, Special Built-In Utilities