Macos 使用Swift中的NSInputStream从STDIN获取输入

我知道如何使用NSFileHandle从STDIN读取数据，但我想知道（1）是否可以使用NSInputStream从STDIN读取数据。另外，我编写了下面的代码，另外一个问题是（2）为什么它会抛出异常？好像是inputStream！有可用的字节

#!/usr/bin/env xcrun swift

import Foundation

let inputStream             = NSInputStream(fileAtPath: "/dev/stdin")

inputStream!.open()

println(inputStream!.hasBytesAvailable)

if(inputStream!.hasBytesAvailable) {
  let readBufferRef         = UnsafeMutablePointer<UnsafeMutablePointer<UInt8>>()
  let readBufferLengthRef   = UnsafeMutablePointer<Int>()
  let readBufferIsAvailable = inputStream!.getBuffer(readBufferRef, length: readBufferLengthRef)

  if readBufferIsAvailable {
    println("Yay")
  }
}

println("Heck")


$ printf "%d\n%d\n" 1 2 | ./stdin_stdout_2.swift 
true
0  swift                    0x000000010d410b68 llvm::sys::PrintStackTrace(__sFILE*) + 40
1  swift                    0x000000010d411054 SignalHandler(int) + 452
2  libsystem_platform.dylib 0x00007fff9a7bdf1a _sigtramp + 26
3  libsystem_platform.dylib 0x00007fff534ade70 _sigtramp + 3100573552
4  CoreFoundation           0x00007fff8f59fc17 -[__NSCFInputStream getBuffer:length:] + 23
5  CoreFoundation           0x00000001114c4314 -[__NSCFInputStream getBuffer:length:] + 2180138772
6  swift                    0x000000010ca85c39 llvm::JIT::runFunction(llvm::Function*, std::__1::vector<llvm::GenericValue, std::__1::allocator<llvm::GenericValue> > const&) + 329
7  swift                    0x000000010cd320b3 llvm::ExecutionEngine::runFunctionAsMain(llvm::Function*, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&, char const* const*) + 1523
8  swift                    0x000000010c96e6ba swift::RunImmediately(swift::CompilerInstance&, std::__1::vector<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> >, std::__1::allocator<std::__1::basic_string<char, std::__1::char_traits<char>, std::__1::allocator<char> > > > const&, swift::IRGenOptions&, swift::SILOptions const&) + 1066
9  swift                    0x000000010c75764b frontend_main(llvm::ArrayRef<char const*>, char const*, void*) + 5275
10 swift                    0x000000010c754a6d main + 1677
11 libdyld.dylib            0x00007fff98fca5c9 start + 1
12 libdyld.dylib            0x000000000000000d start + 1728272965
Stack dump:
0.  Program arguments: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift -frontend -interpret ./stdin_stdout_2.swift -target x86_64-apple-darwin14.1.0 -target-cpu core2 -sdk /Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk -color-diagnostics -module-name stdin_stdout_2 
Segmentation fault: 11

#/usr/bin/env xcrun swift
进口基金会
让inputStream=NSInputStream（文件路径：“/dev/stdin”）
输入流！。开（）
println（inputStream！.hasbytes可用）
if（inputStream！.hasbytes可用）{
让readBufferRef=UnsafeMutablePointer（）
让readBufferLengthRef=UnsafeMutablePointer（）
让readBufferIsAvailable=inputStream！.getBuffer（readBufferRef，长度：readBufferLengthRef）
如果可读缓冲区可用{
println（“耶”）
}
}
println（“Heck”）
$printf“%d\n%d\n”12 |/stdin\u stdout\u 2.swift
真的
0 swift 0x000000010d410b68 llvm:：sys:：PrintStackTrace（u sFILE*）+40
1 swift 0x000000010d411054信号处理器（内部）+452
2 libsystem_platform.dylib 0x00007fff9a7bdf1a_sigtramp+26
3 libsystem_platform.dylib 0x00007fff534ade70_sigtramp+3100573552
4 CoreFoundation 0x00007fff8f59fc17-[\uu NSCFInputStream getBuffer:length:][23
5 CoreFoundation 0x00000001114c4314-[\uu NSCFInputStream getBuffer:length:+2180138772
6 swift 0x000000010ca85c39 llvm:：JIT:：runFunction（llvm:：Function*，std:：_1:：vector const&+329
7 swift 0x000000010cd320b3 llvm:：ExecutionEngine:：RunFunctionsMain（llvm:：Function*，std:：_1:：vector const&，char const*const*）+1523
8 swift 0x000000010c96e6ba swift:：立即运行（swift:：编译器状态&，标准：：_1:：向量常量&，swift:：IRGenOptions&，swift:：silooptions常量&+1066
9 swift 0x000000010c75764b前端_main（llvm:：ArrayRef，char const*，void*）+5275
10 swift 0x000000010c754a6d干管+1677
11 libdyld.dylib 0x00007fff98fca5c9启动+1
12 libdyld.dylib 0x000000000000000d开始+1728272965
堆栈转储：
0程序参数：/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift-frontend-exploration/stdin\u stdout\u 2.swift-target x86\u 64-apple-darwin14.1.0-target cpu core2-sdk/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.10.sdk-color diagnostics-模块名称标准2
分段错误：11

问题在于对

readBufferRef

使用

unsafemtablepointer（）

和

readBufferLengthRef

使用

unsafemtablepointer（）

修改后的代码

#!/usr/bin/env xcrun swift

import Foundation

let inputStream                = NSInputStream(fileAtPath: "/dev/stdin")

inputStream!.open()

println(inputStream!.hasBytesAvailable)

if(inputStream!.hasBytesAvailable) {
  // var readBufferRef         = UnsafeMutablePointer<UnsafeMutablePointer<UInt8>>()
  var readBufferRef            = UnsafeMutablePointer<UInt8>()
  // var readBufferLengthRef   = UnsafeMutablePointer<Int>()
  var readBufferLengthRef      = 0
  // let readBufferIsAvailable = inputStream!.getBuffer(readBufferRef, length: readBufferLengthRef)
  let readBufferIsAvailable    = inputStream!.getBuffer(&readBufferRef, length: &readBufferLengthRef)

  if readBufferIsAvailable {
    println("Yay")
  }
}

println("Heck")

#/usr/bin/env xcrun swift
进口基金会
让inputStream=NSInputStream（文件路径：“/dev/stdin”）
输入流！。开（）
println（inputStream！.hasbytes可用）
if（inputStream！.hasbytes可用）{
//var readBufferRef=unsafemeutablepointer（）
var readBufferRef=unsafemeutablepointer（）
//var readBufferLengthRef=UnsafeMutablePointer（）
变量readBufferLengthRef=0
//让readBufferIsAvailable=inputStream！.getBuffer（readBufferRef，长度：readBufferLengthRef）
让readBufferIsAvailable=inputStream！.getBuffer（&readBufferRef，长度：&readBufferLengthRef）
如果可读缓冲区可用{
println（“耶”）
}
}
println（“Heck”）