Bash 退出不退出

Question

我想知道为什么即使有明确的退出命令，这个脚本也会继续运行。

我有两个文件:

file1.txt 包含以下内容:

aaaaaabbbbbbccccccddddddeeeeeeffffffgggggg

file2.txt with the following content:

111111aaaaaa222222333333ffffff444444

The script (test.sh) is this, two nested loops checking if any line of the first file contains any line of the second file. If it finds a match, it aborts.

#!/bin/bash
path=`dirname $0`

cat $path/file1.txt | while read line
do  
    echo $line
    cat $RUTA/file2.txt | while read another
    do
        if [ ! -z "`echo $line | grep -i $another`" ]; then
            echo "!!!!!!!!!!"
            exit 0
        fi              
    done
done 

即使它在打印第一个 !!!!!!!!!! 后应该退出，我也会得到以下输出:

aaaaaa!!!!!!!!!!bbbbbbccccccddddddeeeeeeffffff!!!!!!!!!!gggggg

exit 不是应该完全结束脚本的执行吗？

Answer 1

原因是管道创建了子进程。改用输入重定向，它应该可以工作

#!/bin/bash

while read -r line
do
    echo "$line"
     while read -r another
    do
        if  grep -i "$another" <<< "$line" ;then
            echo "!!!!!!!!!!"
            exit 0
        fi
    done < file2.txt
done < file1.txt

在一般情况下，输入来自另一个程序而不是文件，您可以使用 process substitution

while read -r line
do
    echo "$line"
     while read -r another
    do
        if  grep -i "$another" <<< "$line" ;then
            echo "!!!!!!!!!!"
            exit 0
        fi
    done < <(command2)
done < <(command1)