Update README.md

README.md

@@ -1,12 +1,156 @@
 # cHTTP
-This is an HTTP library for C, featuring an HTTP(S) server, HTTP(S) client, and much more!
+cHTTP is an HTTP client and server library distributed as a single file with support for HTTPS, virtual hosts, fully non-blocking operations.
+
+## Quick Start
+
+### Your first request
+
+The simplest way to perform a GET request looks like this:
+
+```c
+#include "chttp.h"
+
+int main(void)
+{
+    CHTTP_Response *response;
+
+    int ret = chttp_get(CHTTP_STR("http://coz.is/"), NULL, 0, &response);
+    if (ret == CHTTP_OK) {
+        printf("Received %d bytes\n", response->body.len);
+        chttp_free_response(response);
+    } else {
+        printf("Request failure: %s\n", chttp_strerror(ret));
+    }
+    return 0;
+}
+```
+
+(Note the `http:` schema. If you want HTTPS, you'll have to enable it explicitly! Refer to the HTTPS section.)
+
+Copy this code to `first_request.c` near `chttp.c` and compile it by running:
+
+```sh
+# Linux
+gcc chttp.c first_request.c -o first_request
+
+# Windows (mingw)
+gcc chttp.c first_request.c -o first_request.exe -lws2_32
+```
+
+Then, run the program
+
+```sh
+# Linux
+./first_request
+
+# Windows
+.\first_request.exe
+```
+
+Done!
+
+### Your first server
+
+The setup for a basic server looks like this:
+
+```c
+#include "chttp.h"
+
+int main(void)
+{
+    int ret;
+
+    CHTTP_Server server;
+    ret = chttp_server_init(&server);
+    if (ret < 0) {
+        fprintf(stderr, "Couldn't initialize server (%s)\n", chttp_strerror(ret));
+        return -1;
+    }
+
+    chttp_server_set_reuse_addr(&server, true);
+    chttp_server_set_trace_bytes(&server, true);
+
+    ret = chttp_server_listen_tcp(&server, CHTTP_STR("127.0.0.1"), 8080);
+    if (ret < 0) {
+        fprintf(stderr, "Couldn't start listening (%s)\n", chttp_strerror(ret));
+        return -1;
+    }
+
+    for (;;) {
+
+        CHTTP_Request *request;
+        CHTTP_ResponseBuilder builder;
+        chttp_server_wait_request(&server, &request, &builder);
+
+        chttp_response_builder_status(builder, 200);
+        chttp_response_builder_body(builder, CHTTP_STR("Hello, world!"));
+        chttp_response_builder_send(builder);
+    }
+
+    chttp_server_free(&server);
+    return 0;
+}
+```
+
+Copy this code to a `first_server.c` file and compile it by running
+
+```sh
+# Linux
+gcc chttp.c first_server.c -o first_server
+
+# Windows (mingw)
+gcc chttp.c first_server.c -o first_server.exe -lws2_32
+```
+
+Then, run the program
+
+```sh
+# Linux
+./first_server
+
+# Windows
+.\first_server.exe
+```
+
+While the program is running, open a browser and visit `http://127.0.0.1:8080/`. You should see the text "Hello, world!" sent by the server and a log of the HTTP requests and responses processed by the server in the console.
+
+## HTTPS
+
+HTTPS is supported via OpenSSL, which is easily available on Linux and less so on Windows.
+
+First, install the OpenSSL development libraries:
+
+```sh
+# Ubuntu/Debian Linux
+sudo apt install libssl-dev gcc
+```
+
+Then, enable HTTPS by compiling your program with the following flags:
+
+```sh
+# Linux
+gcc chttp.c main.c -lssl -lcrypto -DHTTPS_ENABLED
+
+# Windows
+gcc chttp.c main.c -lws2_32 -lssl -lcrypto -DHTTPS_ENABLED
+```
+
+## Development Status
+
+The major limitation of cHTTP is HTTPS on Windows. For that to work correctly it will be necessary to port the OpenSSL code to SChannel.
+
+Other limitations:
+* HTTP client doesn't follow redirections (responses with code 3xx)
+* Support for HTTP client cookies is limited
+* HTTP server adherence to the spec can be improved
 
 ## Contributing
 
 Contributions are welcome! The following are some notes on how to work with the codebase. Don't worry if you get something wrong. I will remind you.
 
-The source code in the `src/` directory is intended to be be amalgamated into a single file before compilation. The amalgamation is not only intended as a distribution method, but also as easy-access documentation, and therefore need to be readable. For this reasons:
-1. You never need need to include other cHTTP source files
-2. All inclusions of third-party headers are to be placed inside `src/includes.h`
-3. All files must start with a single empty line, unless they start with an overview comment of the file, in which case they must have no empty lines at the beginning of the file.
-4. All files must end with a single empty line.
+The source code in the src/ directory is intended to be be amalgamated into a single file before compilation. The amalgamation is not only intended as a distribution method, but also as easy-access documentation, and therefore need to be readable. For this reasons:
+
+* You never need need to include other cHTTP source files
+* All inclusions of third-party headers are to be placed inside src/includes.h
+* All files must start with a single empty line, unless they start with an overview comment of the file, in which case they must have no empty lines at the beginning of the file.
+* All files must end with a single empty line.