test -e linuxmi.txt || test -e linuxmi.py && echo "linuxmi exists" || echo "linuxmi does not exist" 排除test 关键字 您实际上不需要使用单词test来执行比较。您所要做的就是将语句括在方括号中,如下所示: ⚡ [ -e linux.py ] && echo "linux.py ex
参数可以是以下任意一项:-e: Returns true value, if file exists -f: Return true value, if file exists and regular file -r: Return true value, if file exists and is readable -w: Return true value, if file exists and is writable -x: Return true value, if file exists and is executable...
file="/home/shiyanlou/test.sh" if [ -r $file ] then echo "The file is readable" else echo "The file is not readable" fi if [ -e $file ] then echo "File exists" else echo "File not exists" fi 结果 The file is readable File exists 思考 浮点运算,比如实现求圆的面积和周长。 exp...
test -e linuxmi.txt || test -e linuxmi.py && echo "linuxmi exists" || echo "linuxmi does not exist" 排除test 关键字 您实际上不需要使用单词test来执行比较。您所要做的就是将语句括在方括号中,如下所示: ⚡ [ -e linux.py ] && echo "linux.py exists" || echo "file1 does not e...
test8.sh exists. /> cat > test10.sh for name in $*#读取脚本的命令行参数数组,还可以写成for name的简化形式。 do echo "Hi, $name" done CTRL+D /> . ./test10.sh stephen ann Hi, stephen Hi, ann while循环声明格式: while command #如果command命令的执行结果为0,或条件判断为真时,执行循环...
echo "the user $1 exists" else useradd $1 echo "123456" | passwd --stdin $1 &> /dev/null echo "Add user $1 finished." fi 练习1:通过命令行参数给定两个数字,输出其中较大的数值; 解: #!/bin/bash # if [ $# -lt 2 ];then ...
TestFile1 does not exist or is empty. 现在创建一个空文件用来测试: [student@studentvm1 testdir]$ File="TestFile1" ; touch $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ; fi ...
-g file exists and has its setgid(2) bit set. -G file exists and has the same group ID as this process. -k file exists and has its sticky bit set. -L file exists and is a symbolic link. -n string length is not zero.
错误信息通常如下: iptables: Chain already exists 2...错误原因分析 2.1 链重复创建如果你在规则脚本或配置文件中多次创建同名链,会出现此错误。这通常是由于脚本中存在重复命令或配置文件不正确导致的。...> 3.3 修改脚本以避免重复创建检查并修改你的配置脚本或文件,确保不会重复创建链。...如果链仍被使用...
echo "$1 is exists" fi if ! grep "^$1\> " /etc/passwd &> /dev/null ;then useradd "$1" echo $1 | passwd --stdin $1 &> /dev/null fi exit 222 注意:此shell脚本中有两处exit命令,去掉exit 22,会执行exit 222,用echo $?可以验证,如果在之间有exit 22,则以后的语句就不会再执行了...