To use gnash on the command-line you can use use the command gnash-raymii ~/flash-file.swf.
To use the commands you must prefix them with the snap name. (gnash-raymii.dump-gnash).
GNU Gnash is the GNU Flash movie player — Flash is an animation
file format pioneered by Macromedia which continues to be
supported by their successor company, Adobe. Flash has been
extended to include audio and video content, and programs written
in ActionScript, an ECMAScript-compatible language. Gnash is
based on GameSWF, and supports most SWF v7 features and some
SWF v8 and v9. SWF v10 is not supported by GNU Gnash.
Enable snaps on Linux Mint and install gnash-raymii
Snaps are applications packaged with all their dependencies to run on all popular Linux distributions from a single build. They update automatically and roll back gracefully.
Snaps are discoverable and installable from the Snap Store, an app store with an audience of millions.
Snap is available for Linux Mint 18.2 (Sonya), Linux Mint 18.3 (Sylvia), Linux Mint 19 (Tara), Linux Mint 19.1 (Tessa) and the latest release, Linux Mint 20 (Ulyana).
You can find out which version of Linux Mint you’re running by opening System info from the Preferences menu.
On Linux Mint 20, /etc/apt/preferences.d/nosnap.pref needs to be removed before Snap can be installed. This can be accomplished from the command line: