Custom LLDB command that generates a cURL command from any URLRequest in Swift

.lldbinit

command regex curl 's/(.+)/expr -l Swift -O -- let anyRequest = %1; if let unwrappedRequest = (anyRequest as? URLRequest), let url = unwrappedRequest.url { var baseCommand = #"curl "\#(url.absoluteString)""#; let quote = String(UnicodeScalar(UInt8(39))); if unwrappedRequest.httpMethod == "HEAD" { baseCommand += " --head"; }; var command = [baseCommand]; if let method = unwrappedRequest.httpMethod, (method != "GET" && method != "HEAD") { command.append("-X \(method)"); }; if let headers = unwrappedRequest.allHTTPHeaderFields { for (key, value) in headers where key != "Cookie" { command.append("-H \(quote)\(key): \(value)\(quote)"); }; }; if let data = unwrappedRequest.httpBody, let body = String(data: data, encoding: .utf8) { command.append("-d \(quote)\(body)\(quote)"); }; print(command.joined(separator: " \\\n\t"));}/'

If you haven't created the .lldbinit file yet, you can create it using:

touch ~/.lldbinit

It creates the .lldbinit file in your home directory.

If you already had created the .lldbinit file, just add the command line to your file.

How to use it, once created and added the .lldbinit file, put a breakpoint where you have some URLRequest instance and just type

curl yourURLRequestInstance in the console

The swift code behind this command regex is an adaptation of this @shaps80 code: https://gist.github.com/shaps80/ba6a1e2d477af0383e8f19b87f53661d

Oh this is a cool idea! Then you have it in any project ok that machine. Nice one!!

Thank you for this! Just FYI, this approach will affect the performance of the the app while processing. I tend to print out curl statements as is processing them.

@chrisvanbuskirk please elaborate. Since this is a LLVM console command, I don't see how this version would affect performance at all? Even my original implementation wouldn't affect performance more than generally printing all over the place. But again, logging is standard practice and in most app usage, negligible.