def ip2num(ip):#ip to int num lp = [int(x) for x in ip.split('.')] return lp[0] << 24 | lp[1] << 16 | lp[2] << 8 | lp[3] def num2ip(num):# int num to ip ip = ['', '', '', ''] ip[3] = (num & 0xff) ip[2] = (num & 0xff00) >> 8
需求说明: 在写脚本的时候,有的时候,需要判断一个字符串是否为空,因此,在此写出如何判断一个字符串为空的方法. 简单来说,就是字符串的比较. 测试脚本: 以下的脚本用于测试str_1和str_2是否是空字符串: #!/bin/bash str_1='' str_2=Badboy if [[ -z $str_1 ]]; then echo str_1 is empty. else echo str_1 is not empty. fi if [[ -z v$str_2 ]]; then echo