Your First Program

Now that your environment is set up and NextStd is installed globally on your system, let’s write your first memory-safe C program.

We are going to replace the traditional, unsafe printf function with NextStd’s type-safe ns_println macro.

The Basic Program

Create a new file named hello.c anywhere on your computer.

Add the following code to print basic text and variables. Notice how we use standard angle brackets for the includes now that NextStd is a system library:

#include <nextstd/ns.h>

int main() {
    // 1. Printing a standard string
    ns_println("Hello, World! Welcome to NextStd.");

    // 2. Printing an integer safely without format specifiers
    int version = 2;
    ns_print("NextStd Version: ");
    ns_println(version); 

    // 3. Printing a floating-point number
    double pi = 3.14159;
    ns_print("Value of Pi: ");
    ns_println(pi);

    return 0;
}

To compile and execute this program, open your terminal and link the necessary NextStd I/O and Error modules:

gcc hello.c -lns_io -lns_error -o hello
./hello

(Note: If you are testing locally inside the cloned repository instead of using the system-wide install, you can still just drop this in examples/hello.c and run make hello)

Adding Terminal Colors

NextStd also provides a dedicated, cross-platform color module to help you build beautiful CLI tools. You don’t need to remember ANSI escape codes; you just include the header and use the macros.

Create a second file named hello_color.c:

#include <nextstd/ns.h>
#include <nextstd/ns_color.h> // Import the color macros

int main() {
    // Printing with a specific color and resetting it afterward
    ns_println(NS_COLOR_GREEN "Success: System initialized safely." NS_COLOR_RESET);

    // Combining styles like bold text with colors
    ns_println(NS_COLOR_CYAN NS_COLOR_BOLD "NextStd is running..." NS_COLOR_RESET);

    // Warning and Error colors
    ns_println(NS_COLOR_YELLOW "Warning: Low memory." NS_COLOR_RESET);
    ns_println(NS_COLOR_RED "Error: Connection lost." NS_COLOR_RESET);

    return 0;
}

Compile and run this exactly like the first one:

gcc hello_color.c -lns_io -lns_error -o hello_color
./hello_color

How It Works

If you are coming from standard C, the code above might look like magic. How does ns_println know whether to print a string, an integer, or a double without you typing %s, %d, or %f?

NextStd leverages C11’s _Generic keyword to inspect the type of the variable at compile time. It then automatically routes your data to the correct, memory-safe Rust backend function (e.g., ns_print_int, ns_print_double, or ns_print_str).

Because there are no format strings, there is zero risk of mismatched types causing undefined behavior or reading garbage memory from the stack. If you try to print a type that NextStd doesn’t support yet, the compiler will safely throw an error before the program ever runs.