Custom Script and Shared Object

Write your custom script:

Create your custom script (e.g., a shell script) that contains the functionality you want to encapsulate:

#!/bin/bash

echo "Running custom script..."
echo "Hello, world!"

Create a C wrapper function:

Write a C function that will serve as a wrapper for executing your script. This function will use the system() function from the C standard library to execute the script. Create a C source file (e.g., wrapper.c) with the following content:

// wrapper.c

#include <stdlib.h>

void run_custom_script() {
    system("./custom_script.sh");
}

Compile the source code:

Use GCC to compile the source code into a shared object. Use the -shared flag to specify that you want to create a shared object, and -fPIC to generate position-independent code, which is required for shared objects. This command compiles wrapper.c into a shared object named libcustom.so.: gcc -shared -fPIC -o libcustom.so wrapper.c

Use the shared object:

Once you've created the shared object, you can use it in other programs to execute your custom script. You can link it with other programs or dynamically load it at runtime using tools like dlopen in your C/C++ programs. For example, you can create a simple C program that uses the shared object:

// main.c

#include <stdio.h>
#include <dlfcn.h>

int main() {
    void *handle = dlopen("./libcustom.so", RTLD_LAZY);
    if (!handle) {
        fprintf(stderr, "Error: %s\n", dlerror());
        return 1;
    }

    void (*run_custom_script)() = dlsym(handle, "run_custom_script");
    if (!run_custom_script) {
        fprintf(stderr, "Error: %s\n", dlerror());
        dlclose(handle);
        return 1;
    }

    run_custom_script();

    dlclose(handle);
    return 0;
}

Compile main.c and link it with libcustom.so:

gcc -o main main.c -ldl

Now, when you run the main program, it will execute the custom script encapsulated within the shared object libcustom.so.