Ubuntu linux installation ./install fails

So I did the command in the pdf of install -inputfile installer_input.txt when I didn't change the name of the installer input, then I ran into the problem of bash not knowing what install was so I did ./install, but when I did that permissions was rejected and when I did sudo ./install it said it couldn't find install again. and when I wrote out the full path of install in the matlab installation folder it still failed

xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ ./install
-bash: ./install: Permission denied
xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ sudo ./install -inputfile installer_input.txt
[sudo] password for adlab:
sudo: ./install: command not found
xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ sudo ./install
sudo: ./install: command not found
xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ ./install
-bash: ./install: Permission denied
xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ sudo ./install
sudo: ./install: command not found
xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ sudo /usr/matlabfiles/matlab_R2018a_glnxa64_trans/install -inputfile installer_input.txt
sudo: /usr/matlabfiles/matlab_R2018a_glnxa64_trans/install: command not found
xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$

https://www.mathworks.com/matlabcentral/answers/377998-why-do-i-get-an-install-invalid-option-i-error-when-trying-to-run-an-installation-silently-o

Edit: thanks walter:sudo sh ./install -inputfile installer_input.txt -mode silent

[Walter Roberson]

What shows up for

ls -ld ./install

[Jonathan Fernow]

xxxxx@localhost:/usr/matlabfiles/matlab_R2018a_glnxa64_trans$ ls -ld ./install

-rw-rw-r-- 1 adlab adlab 8179 Apr 12 13:10 ./install

Answer 1

[Walter Roberson]

sudo sh ./install

[Jonathan Fernow]

I got the below

[sudo] password for adlab:

Preparing installation files ...

Installing ...

---------------------------------------------------------------------------

Error: Installation cannot proceed. You may either:

1. Set an X11 display, and restart the install process

2. Use the silent install feature by specifying the -mode silent option

---------------------------------------------------------------------------

Finished