Index for Section 1

Alphabetical listing for T

Bottom of page

tsort(1)
NAME
  tsort - Sorts an unordered list of ordered pairs (topological sort)

SYNOPSIS
  tsort [file]

STANDARDS
  Interfaces documented on this reference page conform to industry standards
  as follows:

  tsort:  XCU5.0

  Refer to the standards(5) reference page for more information about
  industry standards and associated tags.

OPTIONS
  None

OPERANDS
  file
      Pathname of a test file to be ordered.

      If no file operand is specified, tsort reads standard input.

DESCRIPTION
  The tsort command reads from file or standard input an unordered list of
  ordered pairs, builds an ordered list, and writes it to standard output.

  [Tru64 UNIX]	For creating a subroutine library, do not use tsort; use the
  following command in its place:

       % ar -ts file.a

  The input file should contain pairs of nonempty strings separated by
  spaces.  Pairs of different items indicate a relative order.	Pairs of
  identical items indicate presence, but no relative order.

  [Tru64 UNIX]	You can use tsort to sort the output of the lorder command.

  [Tru64 UNIX]	If file contains an odd number of fields, tsort writes the
  error message:

       tsort:  Specify an even number of data fields.

NOTES
  The LC_COLLATE environment variable does not affect the actions of tsort.

EXIT STATUS
  The following exit values are returned:

  0   Successful completion.

  >0  An error occurred.

EXAMPLES
  To create a subroutine library, enter:

       lorder charin.o scanfld.o scan.o scanln.o
	       | tsort | xargs ar qv libsubs.a

  (Enter the command entirely on one line, not on two lines as shown above.)

  This creates a subroutine library named libsubs.a that contains charin.o,
  scanfld.o, scan.o, and scanln.o.  The ordering of the object modules in the
  library is important.	 The ld command requires each module to precede all
  the other modules that it calls or references.  The lorder and tsort
  commands together add the subroutines to the library in the proper order.

  Suppose that scan.o calls scanfld.o and scanln.o.  scanfld.o also calls
  charin.o.  First, the lorder command creates a list of pairs that shows
  these dependencies:

       charin.o charin.o
       scanfld.o scanfld.o
       scan.o scan.o
       scanln.o scanln.o
       scanfld.o charin.o
       scanln.o charin.o
       scan.o scanfld.o

  Next, the | (vertical bar) sends this list to the tsort command, which
  converts it into the ordering you need:

       scan.o
       scanfld.o
       scanln.o
       charin.o

  Note that each module precedes the module it calls.  charin.o, which does
  not call another module, is last.

  The second | (vertical bar) then sends this list to xargs, which constructs
  and runs the following ar command:

       ar qv libsubs.a scan.o scanfld.o scanln.o charin.o

  This ar command creates the properly ordered library.

ENVIRONMENT VARIABLES
  The following environment variables affect the execution of tsort:

  LANG
      Provides a default value for the internationalization variables that
      are unset or null. If LANG is unset or null, the corresponding value
      from the default locale is used.	If any of the internationalization
      variables contain an invalid setting, the utility behaves as if none of
      the variables had been defined.

  LC_ALL
      If set to a non-empty string value, overrides the values of all the
      other internationalization variables.

  LC_CTYPE
      Determines the locale for the interpretation of sequences of bytes of
      text data as characters (for example, single-byte as opposed to
      multibyte characters in arguments).

  LC_MESSAGES
      Determines the locale for the format and contents of diagnostic
      messages written to standard error.

  NLSPATH
      Determines the location of message catalogues for the processing of
      LC_MESSAGES.

SEE ALSO
  Commands:  ar(1), lorder(1), xargs(1)

  Standards:  standards(5)

Index for Section 1

Alphabetical listing for T

Top of page