如何抢救/捕获“写入文件时出错：管道损坏（Errno）”异常？答案

【问题标题】：How to rescue/catch an "Error writing file: Broken pipe (Errno)" exception?如何抢救/捕获“写入文件时出错：管道损坏（Errno）”异常？
【发布时间】：2019-06-06 07:57:24
【问题描述】：

我的 Crystal 程序输出到 STDOUT，通常通过管道传送到像 less 这样的寻呼机。当用户在查看完整输出之前终止 less 时，应用程序崩溃并出现以下异常：

Unhandled exception: Error writing file: Broken pipe (Errno)
  from /usr/local/Cellar/crystal/0.28.0/src/crystal/system/unix/file_descriptor.cr:79:13 in 'unbuffered_write'
  from /usr/local/Cellar/crystal/0.28.0/src/io/buffered.cr:179:5 in 'flush'
  from /usr/local/Cellar/crystal/0.28.0/src/io/buffered.cr:131:7 in 'write'
  from /usr/local/Cellar/crystal/0.28.0/src/io.cr:481:7 in 'write_utf8'
  from /usr/local/Cellar/crystal/0.28.0/src/string.cr:4254:5 in 'to_s'
  from /usr/local/Cellar/crystal/0.28.0/src/io.cr:184:5 in '<<'
  from /usr/local/Cellar/crystal/0.28.0/src/io.cr:227:5 in 'puts'
  from /usr/local/Cellar/crystal/0.28.0/src/kernel.cr:366:3 in 'puts'
  from lib/log.cr:16:9 in 'print'
  from src/thicket.cr:69:3 in '__crystal_main'
  from /usr/local/Cellar/crystal/0.28.0/src/crystal/main.cr:97:5 in 'main_user_code'
  from /usr/local/Cellar/crystal/0.28.0/src/crystal/main.cr:86:7 in 'main'
  from /usr/local/Cellar/crystal/0.28.0/src/crystal/main.cr:106:3 in 'main'
Failed to raise an exception: END_OF_STACK
[0x1056c232b] *CallStack::print_backtrace:Int32 +107
[0x105692753] __crystal_raise +83
[0x1056ec7cb] *IO::FileDescriptor@Crystal::System::FileDescriptor#unbuffered_write<Slice(UInt8)>:Nil +203
[0x1056ec691] *IO::FileDescriptor@IO::Buffered#flush:IO::FileDescriptor +81
[0x10572899e] *Crystal::main<Int32, Pointer(Pointer(UInt8))>:Int32 +142
[0x10569cfb9] main +9

我找不到一个可以用来解决这个问题的异常类。在 Ruby 中，我会使用 Errno::EPIPE，但 Errno::EPIPE 不是 Crystal 中 Exception 的子类。

如果我救出Errno，未处理的异常就会消失，但其余的仍然存在：

Failed to raise an exception: END_OF_STACK
[0x10d40910b] *CallStack::print_backtrace:Int32 +107
[0x10d3d9533] __crystal_raise +83
[0x10d4335ab] *IO::FileDescriptor@Crystal::System::FileDescriptor#unbuffered_write<Slice(UInt8)>:Nil +203
[0x10d433471] *IO::FileDescriptor@IO::Buffered#flush:IO::FileDescriptor +81
[0x10d46f8fe] *Crystal::main<Int32, Pointer(Pointer(UInt8))>:Int32 +142
[0x10d3e3d99] main +9

【问题讨论】：

标签： crystal-lang epipe

【解决方案1】：

这只是当前版本中的一个错误，您正在点击https://github.com/crystal-lang/crystal/issues/7810

【讨论】：

啊，我不知何故错过了那个问题。谢谢！