while.sh的内容:

cat while.sh

#!/bin/bash

A=1

pstree

cat 1.txt | while read line;do

#起了子进程,看如下pstree

pstree

echo $A

A=${A}_${line}

echo $A

done

echo $A



sh while.sh

├─sshd───sshd───sshd───bash───sh───pstree


├─sshd───sshd───sshd───bash───sh───sh───pstree

1

1_2

1