General Options:

-s : Write in sparse6 format (default)

-g : Write in graph6 format

-z : Make digraph versions and write in digraph6 format

-d : Write in dreadnaut format (can be used with -z)

-v : For each graph, report the size to stderr

-q : Suppress summary

Special Options:

If defined, the digraph version is shown in parentheses; # size parameter called n in the descriptions.

-p#

: path (directed path) on n vertices.

-c#

: cycle (directed cycle) on n vertices.

-e#

: empty graph (digraph with loops only) on n vertices.

-k#

: complete graph (with loops) on n vertices

-b#,#[,#] : complete bipartite graph (directed l->r) on n vertices

minus a matching of given size if present

-f#

: flower snark on 4*# vertices

-P#,# : generalized Petersen graph; usual one is -P5,2

-Q#

: hypercube on 2^n vertices and degree n.

-J#,# : Johnson graph J(n,k), args are n and k.

-C#[,#] : circulant (di)graph.

-T#[,#] : theta (di)graph Theta(#,#,...), give path lengths.

-G#[,#] : (directed) grid, use negative values for open directions

Any number of graphs can be generated at once.