Run your first program.

C: Start with a complete program that prints one line. Follow the run instructions below.

C snippet.c
#include <stdio.h>
#include <string.h>
#include <stdbool.h>
#include <stdlib.h>

int main(void) {
    puts("Hello, learner!");
    return 0;
}

Expected output EXAMPLE

Hello, learner!

Details

Save as snippet.c; compile with gcc -std=c17 -Wall -Wextra snippet.c -lm -o snippet, then run ./snippet.

✓ Verified

Tested on Ubuntu 24.04.5 LTS · · gcc (Ubuntu 13.3.0-6ubuntu2~24.04.1) 13.3.0 · gcc 4:13.2.0-7ubuntu1

Test inputs, results and environment

The exact published code ran in a dedicated Linux test container with prepared inputs. Unprivileged snippet process, external networking disabled, read-only root filesystem, and a fresh temporary working directory. Fixtures and output records are isolated from the application database. Testing covers this example and its stated checks, not every input, operating system, or runtime version. The Linux container shares its host's kernel; this is not a native Windows test.

Architecture / host kernel
x86_64 / 6.18.54.1-microsoft-standard-WSL2
Snippet identity / locale
uid=65534, gid=65534 (unprivileged) / C.UTF-8
Interpreter invocation
gcc -std=c17 -Wall -Wextra -Werror snippet.c -lm -o snippet && ./snippet
Container image ID
sha256:32dc2d998158b6554c99b73b533f423696a0f3e31e8cbea9db10b5eee9a2fadd
Code SHA-256
338597ff7984681d3483cddca785d99f2d0f0d672078d290a02754537797f789
Dependencies
gcc 4:13.2.0-7ubuntu1

Test input setup

These are the prepared inputs used by the test harness. See Details above for the prerequisites and how to run this example.

# No input files required.

Observed standard output

Hello, learner!

Exit code: 0. Standard error: empty. Validation: Exact stdout comparison. System-dependent values above are one recorded run.