1、判断文件夹是否存在 if [ -d /home/q/www ];then echo "true"; else echo "false" ;fi (系统内存在文件夹 /home/q/www) 2、判断文件是否存在 if [ -e /etc/passwd ];then echo "true"; else echo "false" ;fi if [ -f /etc/passwd ];then echo "true"; else echo "false" ;fi 文件存在且大小大于0 if [ -s /etc/passwd ];then echo "true"; else echo "false" ;fi 3、判断文件可读 if [ -r /etc/passwd ];then echo "true"; else echo "false" ;fi 4、判断文件可写 if [ -w /etc/passwd ];then echo "true"; else echo "false" ;fi 5、判断文件可执行 if [ -x /etc/passwd ];then echo "true"; else echo "false" ;fi 6、字符串长度为0,返回真 长度为0 if [ -z "" ];then echo "true"; else echo "false" ;fi 长度不为0 if [ -z "xiaoqiang" ];then echo "true"; else echo "false" ;fi 7、字符串长度不为0,返回真 长度不为0 if [ -n "xiaoqiang" ];then echo "true"; else echo "false" ;fi 长度为0 if [ -n "" ];then echo "true"; else echo "false" ;fi 8、判断字符串相等 if [ "xiaoqiang" = "xiaoqiang" ];then echo "true"; else echo "false" ;fi 9、判断字符串不相等 if [ "xiaoqiang" != "xiaoqiang" ];then echo "true"; else echo "false" ;fi 10、判断整数相等 if [ 1 -eq 1 ];then echo "true"; else echo "false" ;fi 11、判断整数不相等 if [ 1 -ne 1 ];then echo "true"; else echo "false" ;fi 12、判断整数 1 < 2 if [ 1 -lt 2 ];then echo "true"; else echo "false" ;fi 13、判断整数 2 <= 2 if [ 2 -le 2 ];then echo "true"; else echo "false" ;fi 14、判断整数3 > 2 if [ 3 -gt 2 ];then echo "true"; else echo "false" ;fi 15、判断整数 3 >= 3 if [ 3 -ge 3 ];then echo "true"; else echo "false" ;fi 16、逻辑运算 !(非) if [ ! 3 -ge 3 ];then echo "true"; else echo "false" ;fi -a(and) if [ -z "" -a 3 -ge 3 ];then echo "true"; else echo "false" ;fi -o(或) if [ -z "sadfsa" -o 3 -ge 3 ];then echo "true"; else echo "false" ;fi 17、特殊变量 echo "number:$#" 获取参数个数 echo "scname:$0" 获取脚本名称 echo "first:$1" 获取第一个参数 echo "second:$2" 获取第二个参数 echo "argume:[email protected]" 获取所有参数 echo "show parm list :$*" 数据参数的list echo "show process id :$$" 获取进程id echo "show precomm stat:$?" 获取命令执行的结果
时间: 2024-11-05 14:46:46