$* vs $@ linux 中的位置变量

Question

linux 中 $* 和 $@ 位置变量有什么区别。我在某处读到使用 $* 是安全风险。是真的吗。

Answer 1

基本上它们是相同的，除非变量用双引号括起来。然后$*扩展为单个单词并$@扩展为单独的单词。我认为声称$*存在安全风险没有任何好处。

从 bash 手册页：

   *      Expands  to  the positional parameters, starting from one.  When
          the expansion occurs within double quotes, it expands to a  sin-
          gle word with the value of each parameter separated by the first
          character of the IFS special variable.  That is, "$*" is equiva-
          lent to "$1c$2c...", where c is the first character of the value
          of the IFS variable.  If IFS is unset, the parameters are  sepa-
          rated  by  spaces.   If  IFS  is null, the parameters are joined
          without intervening separators.
   @      Expands to the positional parameters, starting from  one.   When
          the  expansion  occurs  within  double  quotes,  each  parameter
          expands to a separate word.  That is, "$@" is equivalent to "$1"
          "$2"  ...   If the double-quoted expansion occurs within a word,
          the expansion of the first parameter is joined with  the  begin-
          ning  part  of  the original word, and the expansion of the last
          parameter is joined with the last part  of  the  original  word.
          When  there  are no positional parameters, "$@" and $@ expand to
          nothing (i.e., they are removed).