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-d: Return true va
[ -d /etc/docker ] && echo "$FILE is a directory." 你也可以使用双括号[[,而不是单括号[。 检查文件是否不存在 与许多其他语言类似,测试表达式可以使用!(感叹号)逻辑非运算符进行否定,例如: FILE=/etc/docker if [ ! -f "$FILE" ]; then echo "$FILE does not exist." fi 或者: [ ! -f ...
9.1. Simple Bash if/else statement Please note the spacing inside the [ and ] brackets! Without the spaces, it won't work! #!/bin/bash directory="./BashScripting" # bash check if directory exists if [ -d $directory ]; then echo "Directory exists" else echo "Directory does not exists...
echo"$1 exists." else echo"$1 is not exists." fi #运行脚本时,后接参数root,youshine,ehhe就是通过$1传递给脚本的 练习中的/dev/null,是黑洞,当我们不需要命令返回信息时,即可指向它。 if语句中通过命令执行的状态返回值(可以在当前命令执行后,echo $?查看)进行判断, 0表示成功执行,1-255表示执行失...
[!-f/etc/docker]&&echo"$FILEdoes not exist" 检查是否存在多个文件 您可以使用-a(或&&与[[)测试是否存在多个文件,而不是使用复杂的嵌套if / else结构: FILE=/etc/dockerif[-f/etc/resolv.conf-a-f/etc/hosts];thenecho"$FILEis a directory"fi ...
Check if a File or Directory Exists Using Code Snippets The previous commands work well for a simple two-line command at a command prompt. However, you can also useBashwith multiple commands. When several commands are strung together, they are called ascript. ...
echo"$FILEdoes not exist." fi #两个括号 if[[ -f"$FILE"]];then echo"$FILEexists." fi 检查文件夹是否存在 使用 -d FILE=/opt/test if[ -d"$FILE"];then echo"$FILEis a directory." fi 检查是否不存在 在前面加个感叹号 ! FILE=/opt/test.txt ...
bash条件判断之if语句 一、条件测试方式: bash命令 [expression] 一个中括号,其中内容为命令,括号两端必须要有空格 [[expression]] 两个中括号,其中内容为关键字,括号两端必须要有空格 test expression 组合测试条件: 与:-a 或:-o 非:! 通常用在[ ],或` `中...
Check if the directory still exists The -d operator allows you to test if a file is a directory. For example, to check if the /etc/filetocheck directory exists, you can use: NOTE: You can also use double brackets [[ instead of [ single brackets. Check if the file doesn’t exist ...
TestFile1 does not exist or is empty. 向文件添加一些内容,然后再测试一次: [student@studentvm1 testdir]$ File="TestFile1" ; echo "This is file $File" > $File ; if [ -s $File ] ; then echo "$File exists and contains data." ; else echo "$File does not exist or is empty." ...