Added Http Post Request Example (#56)

* Added Http Post Request Example

* made url variable const

* polish

* fix compile

* fix mmap

---------

Co-authored-by: jiacai2050 <dev@liujiacai.net>

Author: gmcodentech

book-src/05-01-http-requests.md renamed to book-src/05-01-http-get.md

@@ -0,0 +1,13 @@
+## POST
+
+Parses the supplied URL and makes a synchronous HTTP POST request
+with [`request`]. Prints obtained [`Response`] status, and data received from server.
+
+> Note: Since HTTP support is in early stage, it's recommended to use [libcurl](https://curl.se/libcurl/c/) for any complex task.
+
+```zig
+{{#include ../src/05-02.zig }}
+```
+
+[`request`]: https://ziglang.org/documentation/0.11.0/std/src/std/http/Client.zig.html#L992
+[`response`]: https://ziglang.org/documentation/0.11.0/std/src/std/http/Client.zig.html#L322

book-src/05-02-http-post.md

@@ -24,7 +24,8 @@
 
 - [Web Programming]()
 
-  - [Make HTTP requests](./05-01-http-requests.md)
+  - [HTTP Get](./05-01-http-get.md)
+  - [HTTP Post](./05-02-http-post.md)
 
 - [Algorithms]()
 

book-src/SUMMARY.md

@@ -25,15 +25,30 @@ pub fn main() !void {
     const md = try file.metadata();
     try std.testing.expectEqual(md.size(), file_size);
 
-    const ptr = try std.os.mmap(
-        null,
-        20,
-        std.os.PROT.READ | std.os.PROT.WRITE,
-        if (is_zig_11) std.os.MAP.PRIVATE else .{ .TYPE = .PRIVATE },
-        file.handle,
-        0,
-    );
-    defer std.os.munmap(ptr);
+    const ptr = if (is_zig_11)
+        try std.os.mmap(
+            null,
+            20,
+            std.os.PROT.READ | std.os.PROT.WRITE,
+            std.os.MAP.PRIVATE,
+            file.handle,
+            0,
+        )
+    else
+        try std.posix.mmap(
+            null,
+            20,
+            std.posix.PROT.READ | std.posix.PROT.WRITE,
+            .{ .TYPE = .PRIVATE },
+            file.handle,
+            0,
+        );
+
+    defer if (is_zig_11) {
+        std.os.munmap(ptr);
+    } else {
+        defer std.posix.munmap(ptr);
+    };
 
     // Write file via mmap
     const body = "hello zig cookbook";

src/01-02.zig

@@ -8,7 +8,7 @@ pub fn main() !void {
     _ = args.skip();
     const port_value = args.next() orelse {
         print("expect port as command line argument\n", .{});
-        std.os.exit(1);
+        return error.NoPort;
     };
     const port = try std.fmt.parseInt(u16, port_value, 10);
 

src/04-02.zig

@@ -0,0 +1,63 @@
+const std = @import("std");
+const print = std.debug.print;
+const http = std.http;
+const is_zig_11 = @import("builtin").zig_version.minor == 11;
+
+pub fn main() !void {
+    var gpa = std.heap.GeneralPurposeAllocator(.{}){};
+    defer _ = gpa.deinit();
+    const allocator = gpa.allocator();
+
+    var client = http.Client{ .allocator = allocator };
+    defer client.deinit();
+
+    const uri = try std.Uri.parse("http://httpbin.org/anything");
+
+    const payload =
+        \\ {
+        \\  "name": "zig-cookbook",
+        \\  "author": "John"
+        \\ }
+    ;
+
+    var req = if (is_zig_11) blk: {
+        var headers = http.Headers{ .allocator = allocator };
+        defer headers.deinit();
+
+        var req = try client.request(.POST, uri, headers, .{});
+        errdefer req.deinit();
+
+        req.transfer_encoding = .{ .content_length = payload.len };
+
+        try req.start();
+        var wtr = req.writer();
+        try wtr.writeAll(payload);
+        try req.finish();
+        try req.wait();
+
+        break :blk req;
+    } else blk: {
+        var buf: [1024]u8 = undefined;
+        var req = try client.open(.POST, uri, .{ .server_header_buffer = &buf });
+        errdefer req.deinit();
+
+        req.transfer_encoding = .{ .content_length = payload.len };
+
+        try req.send(.{});
+        var wtr = req.writer();
+        try wtr.writeAll(payload);
+        try req.finish();
+        try req.wait();
+
+        break :blk req;
+    };
+    defer req.deinit();
+
+    try std.testing.expectEqual(req.response.status, .ok);
+
+    var rdr = req.reader();
+    const body = try rdr.readAllAlloc(allocator, 1024 * 1024 * 4);
+    defer allocator.free(body);
+
+    print("Body:\n{s}\n", .{body});
+}