Hello,

I am working on some feature in linux where I need to call a C function(which does opening a binary file, gets checksum value in the file and do some structure manipulation) to it.


Is it possible to call a C function or C executable binary from linux shell script?

I don't think it is possible to call a function from a library.
But you can write a simple C program that calls that function and then call your program from a shell script.

The latter is very possible; for example, whenever in your script you write 'grep', 'wc' or 'cat', it will execute a binary program.

Just to expand on millgates' comment; any command executed by the shell executes either a shell built-in command, or an external command. The 'command' is simply the name of some executable which could be binary object code (i.e. a compiled program), or a script. The shell or any other part of the system doesn't care whether the program was written in C or any other language.
You can write simple programs in C, which invoke whatever functions you want. Presumably, you want the program to output something related to the action it performs. Data can be written to stdout with the likes of printf(), where it then becomes available to your shell/script, as input to other applications via shell pipes. Also, your program can terminate with an exit() code that can be tested in the calling shell, to convey relative success/failure status of your program. By convention, programs that return zero are indicating 'success', and non-zero return status indicates some sort of error or failure. Collectively, these behaviors contribute to the Linux concept of many small tools that can be combined to create a larger overall application that serves a particular purpose. Such is the beauty and elegance of the Linux standard IO idiom.

--- rod.