This is a short, hopefully comprehensible, HTTP server written in C intended to be used as example code for students.
Some notable characteristics about this implementation:
- The code has been written to run on Linux, using epoll (learn about select, poll, kqueue, io_uring somewhere else.)
- This is an implementation of HTTP 1.0
- This is a single-process, single-threaded, co-operative implementation, we wont be using fork, pthreads, tracing gc's nor any off-brand continouations library.
- We are using c11 (c17) not c98.
- We are not hiding any business logic behind macros or global variables.
- bear
- clang
Use Bear to generate a compile_commands.json
this is used by clangd for development.
bear -- clang -std=c17 -I./http-c/src -o ./httpc-server ./src/main.c
If you do not want to install bear or configure clangd then running the cc command which is given to the bear command will compile the example for you
#include <stdio.h>
#include "httpc.h"
struct httpc_response_t index(struct httpc_request_t *req)
{
struct httpc_response_t response = httpc_response_ok();
size_t n_hit = (size_t)(req->context);
req->context = (void *)(n_hit + 1);
uint8_t *buf = calloc(1024, sizof(uint8_t));
int n_trunc = snprintf(buf, 1024, "Hello, World! %d", n_hit);
response->body = httpc_response_string_owned(buf);
return response;
}
int main()
{
struct httpc_server_t server = {0};
if (httpc_server_new(8080, &server) != 0)
{
perror("fatal: failed to create server");
return EXIT_FAILURE;
}
size_t hits = 0;
httpc_server_add_route_with_context("/", &index, &hits);
for (;;)
{
if (httpc_server_await_once(&server, 1) != 0) // timeout is 1 millisecond.
{
perror("fatal: while waiting on httpc server to handle I/O");
httpc_server_close(&server);
return EXIT_FAILURE;
}
}
httpc_server_close(&server);
return EXIT_SUCCESS;
}