Bash配列-ある要素が配列内にあるかどうかを判断するいくつかの方法

配列arrayを宣言し、テスト対象要素varを宣言します。

array=(
element1
element2
element3
)

var="element1"

次にvarがarrayの要素であるかどうかをいくつかの方法でそれぞれテストします。

判断方法1：

echo "${array[@]}" | grep -wq "$var" &&  echo "Yes" || echo "No"

判断方法2：

for i in ${array[@]}
do
   [ "$i" == "$var" ] && echo "yes"
done

判断方法3:これは個人感覚の最も巧みなテスト方法であり,bash配列の内蔵方法を用いた.

[[ ${array[@]/${var}/} != ${array[@]} ]] && echo "Yes" || echo "No"

デモのテスト

#  array、 var
[root(0)@thatsit ~]# array=(
> element1
> element2
> element3
> )
[root(0)@thatsit ~]#
[root(0)@thatsit ~]# var="element1"
#  
[root(0)@thatsit ~]# echo ${array[@]}
element1 element2 element3
[root(0)@thatsit ~]# echo $var
element1
[root(0)@thatsit ~]#
#  1
[root(0)@thatsit ~]# echo "${array[@]}" | grep -wq "$var" &&  echo "Yes" || echo "No"
Yes
[root(0)@thatsit ~]#
#  2
[root(0)@thatsit ~]# for i in ${array[@]}
> do
>    [ "$i" == "$var" ] && echo "yes"
> done
yes
[root(0)@thatsit ~]#
#  3
[root(0)@thatsit ~]# [[ ${array[@]/${var}/} != ${array[@]} ]] && echo "Yes" || echo "No"
Yes
[root(0)@thatsit ~]#

転載先:https://www.cnblogs.com/thatsit/p/bash-shu-zupan-duan-mou-ge-yuan-su-shi-fou-zai-shu.html