function [ ] = git_version_check( username, reponame, checkversion, varargin )

defaultver = 'latest';

defaultmsg = false;

p = inputParser;

p.CaseSensitive = false;

addRequired(p,'username')

addRequired(p,'reponame')

addRequired(p,'checkversion',@ischar)

addParameter(p,'TargetVersion',defaultver,@ischar)

addParameter(p,'WarningOnly',defaultmsg,@islogical)

parse(p,username,reponame,checkversion,varargin{:})

res = p.Results;

repoapisite = ['https://api.github.com/repos/' res.username '/' res.reponame '/releases/' res.TargetVersion];

readfromgit = webread( repoapisite );

checkvers = strsplit(checkversion(2:end), '.');

targetvers = strsplit(readfromgit.tag_name(2:end), '.');

for i=1:length(targetvers)

if i>length(checkvers)

checkver = 0;

else

checkver = str2double(checkvers{i});

end

targetver = str2double(targetvers{i});

if targetver>checkver

msgstr = [{['New version available (' readfromgit.tag_name ')! You are running ' checkversion '.']}...

{['Go to: https://www.github.com/repos/' res.username '/' res.reponame '/releases/' res.TargetVersion...

' for the latest version.']} ];

if ~res.WarningOnly

msgbox(msgstr,'New version available!')

end

warning(cell2mat(msgstr))

break;

elseif targetver<checkver

warning('Running a newer version of this code than the target version.');

break;

end

end

catch me

if strcmp(me.identifier, 'MATLAB:webservices:HTTP404StatusCodeError')

warning(['Failed to read: ' repoapisite '. Unable to connect to GitHub, OR working from a copy of the repo that does not yet have a release. YMMV!'])

else

rethrow(me);

end