用它的协进程/子进程替换当前进程

Question

我有一个程序P希望收到“你好”并输出“为什么？” 在提供功能之前。此功能被其他程序使用，这些程序不知道以“Hello”开始对话是一种常见的礼貌。因此，我想为P这样的工作编写一个包装器（zsh 语法）：

coproc P
print -p Hello  # Send Hello to P
read -pr line   # Read what P has to say
[[ "$line" = "Why?" ]] && Replace current process with the coprocess.
echo Could not get P's attention.

在部分（类似）中使用cat或 会导致不必要的缓冲。我有哪些选择？ddReplace...cat <&p &; exec cat >&p

Answer 1

能够使用 perl 测试以下代码以避免缓冲，尝试这是否适合您

P 的样本版本

$ cat /tmp/P
#!/bin/bash
read input
if [[ $input = "Hello" ]]
then
    echo "Why?"
else
    exit 1
fi
echo "Got Hello from client, working ..."
sleep 10
echo "Need to read some input"
read x
echo "Got: $x"

包装程序

$ cat /tmp/wrapper 
#!/usr/bin/zsh
coproc /tmp/P
print -p Hello  # Send Hello to P
read -pr line   # Read what P has to say
if [[ "$line" = "Why?" ]]; then
    perl -e '$|=1;print $_ while(<>);' <& p &
    perl -e '$|=1;print $_ while(<>);' >& p
else
    echo "Could not get P's attention."
fi

测试运行

$ /tmp/wrapper 
Got Hello from client, working ...
Need to read some input
hi there P!   <== Typed in at teminal
Got: hi there P!