「ShellScript」論理演算子を利用するサンプル

2021年3月3日

使用例

a=13
b=25

#論理演算子! is not
if [ $a != $b ]
then
   echo "$a != $b : a 　not equal b"
else
   echo "$a == $b: a equal b"
fi

#論理演算子 -a and 且つ
if [ $a -lt 100 -a $b -gt 15 ]
then
   echo "$a less than 100 AND $b greater than 15 : 戻り値: true"
else
   echo "$a less than 100 AND $b greater than 15 : 戻り値: false"
fi

#論理演算子　-o or　または
if [ $a -lt 100 -o $b -gt 100 ]
then
   echo "$a less than 100 OR $b greater than 100 : 戻り値: true"
else
   echo "$a less than 100 OR $b greater than 100 : 戻り値: false"
fi
#論理演算子　-o or　または
if [ $a -lt 5 -o $b -gt 100 ]
then
   echo "$a less than 5 OR $b greater than 100 : 戻り値: true"
else
   echo "$a less than 5 OR $b greater than 100 : 戻り値: false"
fi

実行結果
# sh test06.sh
13 != 25 : a 　not equal b
13 less than 100 AND 25 greater than 15 : 戻り値: true
13 less than 100 OR 25 greater than 100 : 戻り値: true
13 less than 5 OR 25 greater than 100 : 戻り値: false