TSORT(1)		  BSD General Commands Manual		      TSORT(1)

NAME
     tsort — topological sort of a directed graph

SYNOPSIS
     tsort [-dlq] [file]

DESCRIPTION
     The tsort utility takes a list of pairs of node names representing
     directed arcs in a graph and prints the nodes in topological order on
     standard output.  Input is taken from the named file, or from standard
     input if no file is given.

     There must be an even number of nodes in the input.  Node names specified
     on the same line should be white space separated.

     Presence of a node in a graph can be represented by an arc from the node
     to itself.  This is useful when a node is not connected to any other
     nodes.

     If the graph contains a cycle (and therefore cannot be properly sorted),
     one of the arcs in the cycle is ignored and the sort continues.  Cycles
     are reported on standard error.

     The options are as follows:

     -d      Turn on debugging.

     -l      Search for and display the longest cycle.	Can take a very long
	     time.

     -q      Do not display informational messages about cycles.  This is pri‐
	     marily intended for building libraries, where optimal ordering is
	     not critical, and cycles occur often.

SEE ALSO
     ar(1)

HISTORY
     The tsort command appeared in Version 7 AT&T UNIX.  This tsort command
     and manual page are derived from sources contributed to Berkeley by
     Michael Rendell of Memorial University of Newfoundland.

BUGS
     The tsort utility does not recognize multibyte characters.

BSD			       December 27, 2006			   BSD