See details in DC help file
<FileType>
<Name>All files</Name>
<IconFile/>
<ExtensionList>file</ExtensionList>
<Actions>
<Action>
<Name>gksu gedit</Name>
<Command>gksu</Command>
<Params>gedit %p</Params>
</Action>
<Action>
<Name>ldd</Name>
<Command>{!VIEWER}</Command>
<Params><?ldd %p?></Params>
</Action>
</Actions>
</FileType>
<FileType>
<Name>All folders</Name>
<IconFile/>
<ExtensionList>folder</ExtensionList>
<Actions>
<Action>
<Name>gksu doublecmd</Name>
<Command>gksu</Command>
<Params>doublecmd %p</Params>
</Action>
<Action>
<Name>ncdu</Name>
<Command>ncdu</Command>
<Params>%t1</Params>
<StartPath>%p</StartPath>
</Action>
</Actions>
</FileType>
Script fileinfo.sh
<FileType>
<Name>FileInfo.sh</Name>
<IconFile/>
<ExtensionList>iso|torrent|so|mo|deb|tar|lha|arj|cab|ha|rar|alz|cpio|7z|ace|arc|zip|zoo|ps|pdf|odt|doc|xls|dvi|djvu|epub|html|htm|exe|dll|gz|bz2|xz|msi|rtf|fb2</ExtensionList>
<Actions>
<Action>
<Name>fileinfo.sh</Name>
<Command>{!VIEWER}</Command>
<Params><?$COMMANDER_PATH/scripts/fileinfo.sh %p?></Params>
</Action>
</Actions>
</FileType>
<FileType>
<Name>Plugins</Name>
<IconFile>cm_configplugins</IconFile>
<ExtensionList>wcx|wlx|wfx|wdx|wdx64|wfx64|wlx64|wcx64</ExtensionList>
<Actions>
<Action>
<Name>Add Plugin</Name>
<Command>cm_AddPlugin</Command>
<Params>%p</Params>
</Action>
</Actions>
</FileType>
<FileType>
<Name>CheckSum</Name>
<IconFile>cm_checksumcalc</IconFile>
<ExtensionList>blake2b|blake2bp|tiger|sha512|sha384|sha256|sha224|sha3|sha|sfv|ripemd160|ripemd128|blake2s|blake2sp|md5|md4|haval|crc32</ExtensionList>
<Actions>
<Action>
<Name>open</Name>
<Command>cm_CheckSumVerify</Command>
</Action>
</Actions>
</FileType>