Originální popis anglicky:
tsort - topological sort
Návod, kniha: POSIX Programmer's Manual
tsort [file]
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>s. Pairs of different items
indicate ordering. Pairs of identical items indicate presence, but not
ordering.
None.
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.
The standard input shall be a text file that is used if no
file operand
is given.
The input file named by the
file operand is a text file.
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
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 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 .
Default.
The standard output shall be a text file consisting of the order list produced
from the partially ordered input.
The standard error shall be used only for diagnostic messages.
None.
None.
The following exit values shall be returned:
- 0
- Successful completion.
- >0
- An error occurred.
Default.
The following sections are informative.
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.
The command:
tsort <<EOF
a b c c d e
g g
f g e f
h h
EOF
produces the output:
None.
None.
None.
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- 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
.
