linux shell 按行读入文件

#/bin/bash

printf "*************************************\n"
echo " cat file while read line"
cat test.txt |while read line
do
  echo $line;
done

printf "*************************************\n"
echo "while read line <file"
while read line
do
&nbsp; echo $line;
done <test.txt

printf "*************************************\n"
echo "for line in cat test.txt"
SAVEIFS=$IFS
IFS=$(echo -en "\n")
for line in $(cat test.txt)
do
&nbsp; echo &nbsp;$line;
done
IFS=$SAVEIFS