Cannot run an executable file although it's right there

Question

I'm completely new to the Unix environment. I've only switched to Ubuntu recently because the program I need doesn't work on the OS that I'm using.

Like the title says: install* won't run. It says no such file or directory, but I know that it is there.

welcome@welcome:~/Downloads/quartus_free$ ls
adm.gz     compare      cyc4gx_we.gz  devinfo_we.gz   gtar     ip.gz         linux.gz    m7k_we.gz     perlsrc.gz   readme.txt   space.txt   stx4_we.gz    version.txt
agx_we.gz  cusp.gz      cycii_we.gz   dsp_builder.gz  gzip     ip_lic.txt    lmf.gz      manifest.txt  qcleanup     sgxii_we.gz  stub.csh    stx_we.gz     
aii_we.gz  cyc3_we.gz   cyc_we.gz     eda.gz          help.gz  libraries.gz  m3k_we.gz   maxii_we.gz   qdesigns.gz  sgx_we.gz    stx2_we.gz  sys_reqs.txt  
common.gz  cyc4e_we.gz  dev_info.txt  gpl_lic.txt     install  license.txt   m7ka_we.gz  md5sum.txt    qt           sopc.g       stx3_we.gz  tutorial.gz   
welcome@welcome:~/Downloads/quartus_free$ ./install
bash: ./install: /bin/csh: bad interpreter: No such file or directory
welcome@welcome:~/Downloads/quartus_free$ 

Answer 1

It's not complaining about the file not being there, it's complaining about the C shell interpreter not being available on your system: you need to install one of the available csh implementations - for example, either

sudo apt-get install tcsh

for the TENEX C Shell ("an enhanced version of Berkeley csh") or

sudo apt-get install csh

for a re-implementation of the original BSD C shell.

Answer 2

The error message could be translated like this:

Hey, I am bash. You ran ./install and this script says I should run it with the interpreter /bin/csh. I can't find this program, though.

So the install script was made for the shell csh and it is not installed on your system.
This is how you can solve that:

sudo apt install csh

When the installation of csh is done, run ./install again.

Answer 3

What the error is saying is that the shell (csh) used to run the executable isn't installed. You can install csh using

sudo apt-get install csh

Answer 4

The error text says ".. /bin/csh: bad interpreter: No such file or directory".

This means that 'install' want's to be executed by '/bin/csh' (has a '#!/bin/csh' in first line), but csh isn't installed.

Run:

sudo apt update
sudo apt install csh

and then rerun ./install