nullglob和数组 [英] nullglob and arrays

问题描述

我可以创建一个数组，然后从该数组中删除

I can create an array, then delete from this array

$ foo=(a b c)

$ unset foo[0]

$ echo ${foo[*]}
b c

但是，如果设置了nullglob，则无法从阵列中删除

However if nullglob is set then I cannot delete from the array

$ shopt -s nullglob

$ foo=(a b c)

$ unset foo[0]

$ echo ${foo[*]}
a b c

推荐答案

unset 'foo[0]'

Bash认为var[1]是一个问题，找不到与之匹配的文件，并且 nullglob的每条指令将其删除，从而导致脚本运行unset 而不是unset var[1]-并没有任何设置.解决此问题的正确方法 问题是引用变量名(并始终显式指定-v): unset -v 'var[1]'.

Bash thinks the var[1] is a glob, doesn't find a file that matches it, and per instruction of nullglob removes it, causing your script to run unset instead of unset var[1] - and nothing gets unset. The correct way to fix this issue is to quote the variable name (and always specify -v explicitly): unset -v 'var[1]'.

§ nullglob

这篇关于nullglob和数组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！