read读到的内容为空，求解答，谢谢

kangkey

我随便写个文件
a.txt：
      aaaaaaaaaaa
然后写个b.sh文件
b.sh：
  wc -l a.txt | read r t
  echo $r
  echo $t

这样读不到r的值，也读不到t的值。
新手上路求哥哥姐姐帮忙解答下。thank友

mpstat

1. read r t <<<$(wc -l a.txt)

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jils2013

把read 和echo 括起来 用小括号；

1. 
   
2. [root@localhost shell]# echo "one two three" | (read a b c;echo "$a $b $c")
   
3. one two three

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--下面是abs的原话，大概意思 变量只在 subshell里生效

# Note also that an echo to a 'read' works within a subshell.
# However, the value of the variable changes *only* within the subshell.
a=aaa # Starting all over again.
b=bbb
c=ccc
echo; echo
echo "one two three" | ( read a b c;
echo "Inside subshell: "; echo "a = $a"; echo "b = $b"; echo "c = $c" )