[Erlang危机](4.4)命名管道

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Named Pipes

命名管道(Named Pipes)

A little known way to connect with an Erlang node that requires no explicit distribution is through named pipes. This can be done by starting Erlang with run_erl, which wraps Erlang in a named pipe 5: 还有一种鲜为人知连接Erlang节点的方法：命名管道(named pipes)，可以通过使用run_erl 启动Erlang来完成 (Erlang会被包裹在命名管道内)5。-------------------------------------------------------------------------------------

$ run_erl /tmp/erl_pipe /tmp/log_dir "erl"

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The first argument is the name of the file that will act as the named pipe. The second one is where logs will be saved 6. 第一个参数是指定作为命名管道的文件，第二个是存放日志的目录6。To connect to the node, you use the to_erl program: 你可以使用 to_erl程序连接到节点上：-------------------------------------------------------------------------------------

$ to_erl /tmp/erl_pipe

Attaching to /tmp/erl_pipe (^D to exit)

1>

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And the shell is connected. Closing stdio (with ˆD) will disconnect from the shell while leaving it running. 连接上后，你可以使用ctrl+D来断开远程节点(只是断开，不会终结远程节点).[5] "erl" is the command being run. Additional arguments can be added after it. For example "erl +K true" will turn kernel polling on.
[6] Using this method ends up calling fsync for each piece of output, which may give quite a performance hit if a lot of IO is taking place over standard output.
[注5]：“erl”就是要运行的命令，你也可以在后面加上其它启动选项如"erl +K ture"会把打开内核kernel轮询。
[注6] ：这个方法最终会调用fsync会同步每一块输出，如果有大量的IO操作产生，性能会下降得很厉害。