ultrix man page for tsort

tsort(1)						      General Commands Manual							  tsort(1)

Name
       tsort - create topological sort

Syntax
       tsort [file]

Description
       The  command  produces  on the standard output a totally ordered list of items consistent with a partial ordering of items mentioned in the
       input file.  If no file is specified, the standard input is understood.

       The input consists of pairs of items (nonempty strings) separated by blanks.  Pairs of different items indicate ordering.  Pairs of identi-
       cal items indicate presence, but not ordering.

Diagnostics
       Odd data: there is an odd number of fields in the input file.

See Also
       lorder(1)

																	  tsort(1)