Why some scripts start with #

[New buDDy]

Hi,
This makes me always confuse. Why some script starts with #. What is the basic explanation behind this. Second thing I have executed a binary compiled file on Linux. Here a error comes up denoting ENOEXEC. The execution command was proper. I was waiting for ENOENT and do have some solution for the same. So what mistake has happened here by me. Any suggestion will be helpful. Thanks.

[Dr. V]

The error is related to Exec Format Error. This means when you try to execute a file the system find it as a invalid executable format and the error is returned. The most commonly format under this category is ELF. Also note down a important part that the files executed under the shell will run ASCII files. Every slight change can make the file invalid.

[MrChris-]

It simply means that the binary compiled executable file has a invalid format. Check that you have given elf format to the same. The shell in your system will claim it as no such file or directory but on the other hand the binary exits. This normally apply to the ELF interpreter. So making some slight changes can resolve your problem.

[Calvin K]

Here when the Unix kernel runs a program it takes a look on the first 16 bit of the file. This first 16 bits are also called as magic number. This number prohibit kernel from doing some wrong execution. If the kernel fails to get this number then the ENOEXEC error returns on the screen. The file is only executable if this numbers are identified by the kernel. Second thing if you move to different executable file format then you have option where the kernel is told not only to execute but also how to execute. But there is a thin line under this option which can get your the above listed error.