топологическая сортировка (topological sort)
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)
tsort — topological sort
Синопсис (Synopsis)
tsort [file]
Описание (Description)
The tsort utility shall write to standard output a totally
ordered list of items consistent with a partial ordering of items
contained in the input.
The application shall ensure that the input consists of pairs of
items (non-empty strings) separated by <blank> characters. Pairs
of different items indicate ordering. Pairs of identical items
indicate presence, but not ordering.
Параметры (Options)
None.
Операнды (Operands)
The following operand shall be supported:
file A pathname of a text file to order. If no file operand
is given, the standard input shall be used.
Стандартный ввод (Stdin)
The standard input shall be used if no file operand is specified,
and shall be used if the 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 file shall be a text file.
Переменные окружения (Environment variables)
The following environment variables shall affect the execution of
tsort:
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 a text file consisting of the order
list produced from the partially ordered input.
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)
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)
The LC_COLLATE variable need not affect the actions of tsort.
The output ordering is not lexicographic, but depends on the
pairs of items given as input.
Примеры (Examples)
The command:
tsort <<EOF
a b c c d e
g g
f g e f
h h
EOF
produces the output:
a
b
c
d
e
f
g
h
Обоснование (Rationale)
None.
Будущие направления (Future directions)
None.
Смотри также (See also)
The Base Definitions volume of POSIX.1‐2017, Chapter 8,
Environment Variables
