How can I resolve the error "cannot execute binary file"?

Usually that error message means Linux doesn't recognize the file as a shell script or as an executable file.

Typically the cause is running an executable on the wrong architecture - if you try to run x86 executables on an ARM CPU, this message comes up.

Did /usr/bin/id get overwritten, possibly?

Try to run it using ./executablefilename instead of using sh executablefilename. It's not a shell script after all.

The problem is running a binary for a different processor architecture. You can use objdump (from binutils) to check architecture of binaries. You can use uname to check architecture of a machine.

e.g. I encountered this error "cannot execute binary file" when installing FF.Communicator - a firefox plugin for chrome (so I can run pages that use java applets).

• objdump shows the binary is 64-bit elf64-x86-64

• uname shows my machine is 32-bit i686

  $ ./FF.Communicator bash: ./FF.Communicator: cannot execute binary file $ uname -mpio i686 i686 i386 GNU/Linux $ objdump -a ./FF.Communicator ./FF.Communicator: file format elf64-x86-64 ./FF.Communicator

• objdump on a working binary on my machine shows it is 32-bit elf32-i386

  $ objdump -a /bin/ls /bin/ls: file format elf32-i386

Using these tools you can check architectures of machines and binaries - not just intel architectures but any processor.

For Mac OSX users, you can find out the architecture info of a specific file using the "file" command:

$ file filename_here

I'm making some wild guesses here, but it looks like the following is happening:

1. You log in over SSH, triggering bash to run your ~/.profile or ~/.bashrc to set up your environment for you (this is normal).
2. At some point it tries to execute /bin/id to get your uid, which fails, causing integer expression error, and terminating the script before it can set up your $PATH.
3. Because your $PATH is not set, bash is only able to run commands with the full path specified.

Use export PATH=/bin:/usr/bin:/sbin:/usr/sbin to fix the $PATH issue until you can fix the root cause of /bin/id failing.

This means that you are trying to execute a binary file using your bash script which is not intended to be run as you trying it to be. It is already a binary file and you are trying your $SHELL to parse and run it.

in a very simple example, if you try to run `w' command like

$ bash w
/usr/bin/w: /usr/bin/w: cannot execute binary file

similarly you might be hitting the same method or as it looks from your code snippet.

While , for the remaining for your commands, Al these halt, shutdown , reboot etc commands are the root owned commands and need super-user prilveges to run and perform the required operation. normal users can't run them another explanation is that these commands are placed at /sbin/ and /usr/sbin , which might not be in your $PATH variable ( which is used to validate commands in your custody )