No such file or directory? But the file exists!

You're probably trying to run a 32-bit binary on a 64-bit system that doesn't have 32-bit support installed.

There are three cases where you can get the message “No such file or directory”:

• The file doesn't exist. I presume you've checked that the file does exist (perhaps because the shell completes it).
• There is a file by that name, but it's a dangling symbolic link.
• The file exists, and you can even read it (for example, the command file shank-linux-120720110-1-bin displays something like “ELF 32-bit LSB executable …”), and yet when you try to execute it you're told that the file doesn't exist.

The error message in this last case is admittedly confusing. What it's telling you is that a key component of the runtime environment necessary to run the program is missing. Unfortunately, the channel through which the error is reported only has room for the error code and not for this extra information that it's really the runtime environment that's to blame. If you want the technical version of this explanation, read Getting “Not found” message when running a 32-bit binary on a 64-bit system.

The file command will tell you just what this binary is. With a few exceptions, you can only run a binary for the processor architecture that your release of Ubuntu is for. The main exception is that you can run 32-bit (x86, a.k.a. IA32) binaries on 64-bit (amd64, a.k.a. x86_64) systems.

In Ubuntu up to 11.04, to run a 32-bit binary on a 64-bit installation, you need to install the ia32-libs package . You may need to install additional libraries (you'll get an explicit error message if you do).

Since 11.10 (oneiric) introduced multiarch support, you can still install ia32-libs, but you can choose a finer-grained approach, it's enough to get libc6-i386 (plus any other necessary library).

64 bit Ubuntu Multiarch systems

Follow this answer only if the output of file file-name shows,

file-name: ELF 32-bit LSB  executable, Intel 80386, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.8, not stripped

To run 32bit executable file in a 64 bit multi-arch Ubuntu system, you have to add i386 architecture and also you have to install libc6:i386,libncurses5:i386,libstdc++6:i386 these three library packages.

sudo dpkg --add-architecture i386
sudo apt-get update
sudo apt-get install libc6:i386 libncurses5:i386 libstdc++6:i386
./file-name

To expand on @Gilles answer, there are at least three scenarios resulting in this error:

1. The file doesn't exist.
2. The file exists but is a dangling symbolic link.
3. The file exists (e.g. file command works), making for a puzzling error message. This may mean there's a problem with the loader.

Categories of loader problems:

1. An executable's loader does not exist. You can check this using the file command and see if the loader does exist. E.g.

   file lmgrd
   lmgrd: ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked, interpreter /lib64/ld-lsb-x86-64.so.3, for GNU/Linux 2.6.18, stripped
   

   Notice interpreter /lib64/ld-lsb-x86-64.so.3; if this file does not exist, you need to install it. For this particular loader on 16.04, the answer turned out to be sudo apt-get install lsb.

2. Issues with a script's loader (see this answer).

3. Missing shared libraries -- use ldd <file-name> to check for any "not found" libraries. See this answer for more info.

The loader not existing could be due to a 32/64 bit mismatch or some other reason. There might be other kinds of loader errors I don't know about.

Here's a transcript showing a bit more about the nature of the problem, and how to fix it as of Ubuntu 16.04. Notice that even though file reports "dynamically linked", ldd reports "not a dynamic executable".

$ ./myprogram
bash: myprogram: No such file or directory

$ file myprogram
myprogram: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), dynamically linked, interpreter /lib/ld-linux.so.2, for GNU/Linux 2.2.5, not stripped

$ ldd myprogram
    not a dynamic executable

Once you install libc6:i386, things start improving...

$ sudo apt-get install libc6:i386 # the initial fix
...

$ ldd myprogram
    linux-gate.so.1 =>  (0xf77fd000)
    libc.so.6 => /lib/i386-linux-gnu/libc.so.6 (0xf7626000)
    /lib/ld-linux.so.2 (0x56578000)

$ ./myprogram
myprogram: error while loading shared libraries: libstdc++.so.6: cannot open shared object file: No such file or directory

To complete the job, you may need to identify and install additional libraries one at a time...

$ sudo apt-get install libstdc++6:i386 ## may require various additional libs

$ ./myprogram
... works correctly ...

I don't know if there is a systematic way of identifying the correct libraries to install. There is a bit of guesswork mapping the error messages to package names (tab completion helps).

By installing the deb for 32 bit I realized I was missing some libraries (in addition to ia32-libs and libc6). I first solved this problem by giving this command:

sudo apt-get install -f          

Then I got another error:

Message: SDL_GL_LoadLibrary 
Error: Failed loading libGL.so.1

Obviously, these libraries were properly installed. Without going into details I had to link the libraries by hand. I realized then that could also an easier solution through Synaptic install the following packages:

libgl1-mesa-glx:i386
libgl1-mesa-dri: i386.

After that the next problem was the black screen while playing, which I solved by replacing the executable in /Shank/bin with this: http://treefort.icculus.org/smb/smb-linux-mesa-hotfix-test.tar.bz2.

I hope it will be useful to someone. If you need more help or more details please feel free to contact me.