TRED(1) General Commands Manual TRED(1)

# [NAME](#NAME)

tred - transitive reduction filter for directed graphs

# [SYNOPSIS](#SYNOPSIS)

**tred** \[ **-ovr?** ] \[ *files* ]

# [DESCRIPTION](#DESCRIPTION)

**tred** computes the transitive reduction of directed graphs, and prints the resulting graphs to a file or standard output. This removes edges implied by transitivity. Nodes and subgraphs are not otherwise affected. The \`\`meaning'' and validity of the reduced graphs is application dependent. **tred** is particularly useful as a preprocessor to *dot* to reduce clutter in dense layouts.

Undirected graphs are silently ignored.

# [OPTIONS](#OPTIONS)

The following options are supported:

[**-o FILE**](#o)

Redirect output to the given file. By default, output goes to stdout.

[**-v**](#v)

Verbose output to stderr.

[**-r**](#r)

Print information of removed edges to stderr.

**-?**

Print usage information.

# [OPERANDS](#OPERANDS)

The following operand is supported:

[*files*](#files)

Names of files containing 1 or more graphs in dot format. If no *files* operand is specified, the standard input will be used.

# [BUGS](#BUGS)

Using bitmaps internally would substantially decrease running time.

# [DIAGNOSTICS](#DIAGNOSTICS)

If a graph has cycles, its transitive reduction is not uniquely defined. In this case *tred* emits a warning.

# [AUTHORS](#AUTHORS)

Stephen C. North <north@research.att.com>  
Emden R. Gansner <erg@research.att.com>

# [SEE ALSO](#SEE_ALSO)

[gc(1)](/man/os/graphviz/gc.1), [dot(1)](/man/os/graphviz/dot.1), [acyclic(1)](/man/os/graphviz/acyclic.1), [gvpr(1)](/man/os/graphviz/gvpr.1), [gvcolor(1)](/man/os/graphviz/gvcolor.1), [ccomps(1)](/man/os/graphviz/ccomps.1), [sccmap(1)](/man/os/graphviz/sccmap.1), [libgraph(3)](/man/os/graphviz/libgraph.3)

21 March 2001

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Document: tred(1) from graphviz 15.1.1-r2 (Chainguard OS)
Source: https://gitlab.com/graphviz/graphviz