How to pass parameters to linux system call?

@lia 

In Linux, system calls are typically made using the C programming language. To pass parameters to a system call, you need to follow these steps:

1. Include the necessary header files: Include the appropriate header file(s) that define the system call you want to use. These header files can vary depending on the system call you are using.
2. Declare variables: Declare variables to hold the values you want to pass to the system call. The variables should have the appropriate types based on the expected parameters of the system call.
3. Populate the variables: Assign values to the variables based on the parameters you want to pass to the system call.
4. Make the system call: Call the system call function and pass the variables as arguments. The order and number of arguments will depend on the specific system call being used.

Here's a basic example of passing parameters to the open() system call, which opens a file:

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#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

int main() {
    // Declare variables
    char filename[] = "example.txt";
    int flags = O_RDONLY;
    mode_t mode = S_IRUSR;

    // Make the system call
    int fileDescriptor = open(filename, flags, mode);

    // Check if open was successful
    if (fileDescriptor == -1) {
        // Handle error
    } else {
        // Use the file descriptor
    }

    return 0;
}

In this example, the open() system call is made with three parameters: filename (name of the file to open), flags (specifying the open mode), and mode (specifying the file permissions).