Since you are using -r flag with matlab command, you would not require the pipe symbol to invoke the 'hello.m'. Modifying the command as below might help resolve the issue:
>>sudo ./matlab -r fol1/hello.m -nosplash -nodesktop
Refer the below link:
https://www.mathworks.com/matlabcentral/answers/230206-error-running-matlab-from-linux-command-line?s_tid=answers_rc1-2_p2_MLT
