Linux 2.6 - man page for tsort (linux section 1posix)
|Linux & Unix Commands - Search Man Pages
TSORT(P) POSIX Programmer's Manual TSORT(P)
tsort - topological sort
The tsort utility shall write to standard output a totally ordered list of items consis-
tent 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.
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, Inter-
nationalization 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 interna-
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 argu-
ments and input files).
Determine the locale that should be used to affect the format and contents of diag-
nostic messages written to standard error.
Determine the location of message catalogs for the processing of LC_MESSAGES .
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.
The following exit values shall be returned:
0 Successful completion.
>0 An error occurred.
CONSEQUENCES OF ERRORS
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.
a b c c d e
f g e f
produces the output:
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 orig-
inal Standard can be obtained online at http://www.opengroup.org/unix/online.html .
IEEE/The Open Group 2003 TSORT(P)
All times are GMT -4. The time now is 11:05 AM.