MATLAB output to PHP variable -

i have matlab function. have called function php code , wants receive return value of matlab function php variable. please me out. matlab :

function img =tigerprinting(udir, pdir, template) % clc; % clear all; imdir = udir; imdir=strcat(imdir,'\'); b=template; % disp(b) temp=imread([imdir,b]); % disp(temp)   pd=pdir;   % disp(pd)   img = '';   p=strcat(pd,'\*.jpg');   pd=strcat(pd,'\');   %disp(pd)   listing=dir(p);   x=size(listing);   x=x(1);    % disp(x)   i=1:x       a=imread([pd,listing(i).name]);      % disp(a)       d=tempmatch(a,temp);      % disp(d)       if d>0          % disp(strcat('* ',b,' found in image  ',listing(i).name));           img = strcat(img,',',listing(i).name);       else           % disp(strcat('* ',b,' not found in image  ',listing(i).name));       end   end  display(img);  %quit force  end 

this function working , img contains desire value

php code :

$command = "matlab  -wait -nojvm -nodesktop -nodisplay -r \"  tigerprinting('".$l_udir."','".$l_pdir."','".$left_flank ."');\" ";          $ot = exec($command);         echo($ot); 

but $ot echos nothing.