Eval!
shell> a=abc shell> b=def shell> $a=ghi ///Wrong ! $a-->only as right value! shell> eval $a=nice /// Right! shell> echo $abc nice shell>eval "string" ///eval 会和后面的字符串合并起来 as a single commnd！
#!/bin/bash #ind-ref.sh: 间接变量引用. #访问一个以另一个变量内容作为名字的变量的值. a=letter_of_alphabet # 变量"a"的值是另一个变量的名字. letter_of_alphabet=z z=abcdef echo # 直接引用. echo "a = $a" # a = letter_of_alphabet # 间接引用. eval a=\$$a echo "Now(one) a = $a" # now a = z # 2次间接引用. #+ 加上上面那一次! eval a=\$$a echo "Now(tow) a = $a" # now a = abcdef echo
