重击:重复字符多次 [英] Bash: repeat character a variable number of times

问题描述

根据以下问题和反省:

https://unix.stackexchange.com/questions/188658/使用-printf命令编写一个字符n次-

和

如何在bash中重复一个字符?

我想学习如何设置一个字符/字符串的重复值.例如，以下代码非常有效:

I would like to learn how one might go about parameterizing the repeat value for a character/string. For example, the followings works spiffingly:

printf "   ,\n%0.s" {1..5}

但是，如果我想参数化"5"，请说:

However, if I wanted to parameterize '5', say:

num=5

我似乎无法正确进行扩展才能完成此工作.例如:

I cannot seem to get the expansion correct to make this work. For instance:

printf "   ,\n%0.s" {1..$((num))}

失败.

任何想法/想法都将受到欢迎-我认为有一种方法可以做到这一点而不必求助于perl或awk，所以只是对poss感到好奇.

Any thoughts/ideas would be most welcome - I reckon there's a way to do this without having to resort to perl or awk so just curious if poss.

谢谢！

推荐答案

如果可以将命令构建为字符串(具有所需的所有参数扩展)，则可以对其进行评估.这将打印X num 次:

If you can build the command as a string -- with all the parameter expansion you want -- then you can evaluate it. This prints X num times:

num=10
eval $(echo printf '"X%0.s"' {1..$num})

这篇关于重击:重复字符多次的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！