tsort

Topological sort, perform a topological sort on the given FILE, or standard input if no input file is given or for a FILE of '-'.

Syntax
      tsort [options] [file]

Options

--help
--version

'tsort' reads its input as pairs of strings, separated by blanks,
indicating a partial ordering.  The output is a total ordering that
corresponds to the given partial ordering.

   For example

     tsort <<EOF
     a b c
     d
     e f
     b c d e
     EOF

will produce the output

     a
     b
     c
     d
     e
     f

'tsort' will detect cycles in the input and writes the first cycle
encountered to standard error. <eof a
     b
     c
     d
     e
     f
     eof will produce the output detect cycles in input and writes first cycle
encountered to standard error.

note that for given partial ordering generally there is no unique total ordering.

"There is always room at the top" ~ Daniel Webster

Related linux commands:

sort - Sort text files.
Equivalent Windows commands: SORT - Sort input.