Linux Shell判断字符串是否存在包含关系

在Pyhton里判断字符串是否存在包含关系非常简单，只要if a in b就行了，但如何在Shell中判断字符串的包含关系呢？

#! /bin/bashvar1="hello"var2="he"#方法1if [ ${var1:0:2} = $var2 ]; then    echo "1:include"fi#方法2echo "$var1" | grep -q "$var2"if [ $? -eq 0 ]; then    echo "2:include"fi#方法3echo "$var1" |grep -q "$var2" && echo "include" ||echo "not"#方法4[[ "${var1/$var2/}" != "$var2" ]] && echo "include" || echo "not"其他方法：expr或awk的index函数${var#...}                  ${var%...}${var/.../...}