tgprint.m

function tgprint(varargin)
% TGPRINT send an image to a Telegram bot
%
% Use tgprintf() in the same way as sprintf()
% Example: figure(1); plot(x,y);
%          tgprint();
% 
% There are two sending modes:
% (1) tgprint('photo'): send an image w/ compression using sendPhoto
% (2) tgprint('document'): send an image w/o compression using sendDocument
% 
% Define token and chat_id before use, 
% which are the authorization token of the target Telegram bot 
% and the identifier or username of the target chat
%
% Please refer the following post 
% "Creating a Telegram bot for personal notifications"
% https://www.forsomedefinition.com/automation/creating-telegram-bot-notifications/
% 
% This also uses urlreadpost by Dan Eills
% https://www.mathworks.com/matlabcentral/fileexchange/27189-urlreadpost-url-post-method-with-binary-file-uploading
% 
% Seongsik Park
% seongsikpark@postech.ac.kr

options = 'photo';
if nargin > 0
    options = varargin{1};
end

filename = 'temp.png';
if exist(filename,'file')
    warning('temporay file ''%s'' wil be overwritten!',filename);
end

print(gcf,filename,'-dpng');

f = fopen(filename,'rb');
d = fread(f,Inf,'*uint8')';
fclose(f);

% default token and chat_id
token = DEFAULT_TOKEN_HERE
chat_id = DEFAULT_CHAT_ID_HERE;

if strcmpi(options,'photo')
    sendstr = ['https://api.telegram.org/bot',token,'/sendPhoto'];
    urlreadpost(sendstr,{'chat_id',chat_id,'photo',d}); 
else
    sendstr = ['https://api.telegram.org/bot',token,'/sendDocument'];
    urlreadpost(sendstr,{'chat_id',chat_id,'document',d}); 
end

end