Duktape
如何在C语言中获取网页JavaScript的返回值?
在Python中,你可以使用requests库来获取网页内容,并使用BeautifulSoup或正则表达式来解析和提取JavaScript返回的数据。以下是一个示例代码:,,“python,import requests,from bs4 import BeautifulSoup,,url = ‘http://example.com’,response = requests.get(url),soup = BeautifulSoup(response.content, ‘html.parser’),,# 假设JS数据在一个特定的script标签中,script_tag = soup.find(‘script’, {‘type’: ‘application/json’}),if script_tag:, js_data = script_tag.string, print(js_data),else:, print(“No JavaScript data found”),`,,这段代码首先发送一个HTTP请求到指定的URL,然后使用BeautifulSoup解析HTML内容,最后查找包含JavaScript数据的特定`标签并提取其内容。
如何在C语言中调用JavaScript文件?
在C语言中调用JavaScript文件,可以通过嵌入一个JavaScript引擎(如V8、SpiderMonkey等)来实现。这通常涉及以下几个步骤:,,1. **初始化JavaScript引擎**:加载并初始化JavaScript引擎。,2. **执行JavaScript代码**:通过引擎提供的API执行JavaScript代码。,3. **处理返回值和错误**:获取执行结果或错误信息。,,以下是一个简化的示例,假设使用V8引擎:,,“c,#include,#include,#include,,void ExecuteJavaScript(const char* js_code) {, // Initialize V8., v8::V8::InitializeICUDefaultLocation(“”);, v8::V8::InitializeExternalStartupData(“”);, std::unique_ptr platform = v8::platform::NewDefaultPlatform();, v8::V8::InitializePlatform(platform.get());, v8::V8::Initialize();,, // Create a new Isolate and make it the current one., v8::Isolate::CreateParams create_params;, create_params.array_buffer_allocator = v8::ArrayBuffer::Allocator::NewDefaultAllocator();, v8::Isolate* isolate = v8::Isolate::New(create_params);, {, v8::Isolate::Scope isolate_scope(isolate);,, // Create a stack-allocated handle scope., v8::HandleScope handle_scope(isolate);,, // Create a new context., v8::Local context = v8::Context::New(isolate);,, // Enter the context for compiling and running the script., v8::Context::Scope context_scope(context);,, // Compile the source code., v8::Local source = v8::String::NewFromUtf8(isolate, js_code, v8::NewStringType::kNormal).ToLocalChecked();, v8::Local script = v8::Script::Compile(context, source).ToLocalChecked();,, // Run the script to get the result., v8::Local result = script-˃Run(context).ToLocalChecked();,, // Convert the result to an UTF8 string and print it., v8::String::Utf8Value utf8(isolate, result);, printf(“%s\n”, *utf8);, },, // Dispose the isolate and tear down V8., isolate-˃Dispose();, v8::V8::Dispose();, v8::V8::ShutdownPlatform();, delete create_params.array_buffer_allocator;,},,int main() {, const char* js_code = “function add(a, b) { return a + b; } add(3, 4);”;, ExecuteJavaScript(js_code);, return 0;,},“,,这个示例展示了如何在C程序中嵌入V8引擎,编译并运行一段简单的JavaScript代码。