在 bash 中循环元组? [英] Loop over tuples in bash?

问题描述

是否可以在 bash 中循环元组?

Is it possible to loop over tuples in bash?

举个例子，如果以下内容有效，那就太好了:

As an example, it would be great if the following worked:

for (i,j) in ((c,3), (e,5)); do echo "$i and $j"; done

是否有一种解决方法可以让我遍历元组?

Is there a workaround that somehow lets me loop over tuples?

推荐答案

$ for i in c,3 e,5; do IFS=","; set -- $i; echo $1 and $2; done
c and 3
e and 5

关于 set 的这种使用(来自 man builtins):

About this use of set (from man builtins):

选项处理后剩余的任何参数都被视为值对于位置参数，并按顺序分配给 $1、$2、... $n

Any arguments remaining after option processing are treated as values for the positional parameters and are assigned, in order, to $1, $2, ... $n

IFS="," 设置字段分隔符，因此每个 $i 都被分割为 $1 和 $2> 正确.

The IFS="," sets the field separator so every $i gets segmented into $1 and $2 correctly.

通过本博客.

更正确的版本，正如@SLACEDIAMOND 所建议的:

more correct version, as suggested by @SLACEDIAMOND:

$ OLDIFS=$IFS; IFS=','; for i in c,3 e,5; do set -- $i; echo $1 and $2; done; IFS=$OLDIFS
c and 3
e and 5

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