如果文件存在，则执行 if 块中的代码；如果文件不存在，则执行 else 块中的代码。二. 单/双方括号 在 Bash 脚本中，确定文件是否存在的最简单方法之一是用[ .. .]和选项-e。语法：if [ -e "/path/to/file" ]; then echo "File exists." else echo "File does not e
Check Empty String 1 2 3 4 5 6 1. 2. 3. 4. 5. 6. if [[ -z "$emptyString" ]]then echo "Empty"else echo "Not Empty"fi 1. Here is a reference material from Stackoverflowhttp://stackoverflow.com/questions/3767267/check-if-file-exists 1 2 3 4 5 6 7 8 9 1...
在Bash Shell中,可以使用复合条件来在一个if语句中检查多个条件。复合条件主要有两种形式:逻辑与(&&)和逻辑或(||)。 1. 逻辑与(&&): - 概念:逻辑与用于同时检查多个条件...
7.1.1.4. 检查shell选项 加入到你的Bash配置文件中去: # These lines will print a message if the noclobber option is set: if [ -o noclobber ] then echo "Your files are protected against accidental overwriting using redirection." fi 环境以上的例子将在命令行输入后开始工作: anny ~> if [ -o ...
11. Bash File Testing #!/bin/bash file="./file" if [ -e $file ]; then echo "File exists" else echo "File does not exists" fi 1. 2. 3. 4. 5. 6. 7. Similarly for example we can use while loop to check if file does not exists. This script will sleep until file does exi...
이렇게 세가지는 매우 자주 사용하는 것이니 꼭 외워두어야 겠습니다. 이상 shell script (bash) 에서 file 유무 체크하는 방법과 옵션 (file exist check)에 대한 글 이였습니다....
anny ~> ./msgcheck.sh This scripts checks the existence of the messages file. Checking... /var/log/messages exists. ...done. 7.1.1.4. 检查shell选项 加入到你的Bash配置文件中去: # These lines will print a message if the noclobber option is set: ...
Run one of the following commands to check if the file exists: 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 [[ ...
在脚本中,if语句的不同部分通常是良好分隔的。以下是一些简单的例子: 7.1.1.3. 检查文件 第一个例子检查一个文件是否存在: anny ~> msgcheck.shanny ~> 7.1.1.4. 检查shell选项 加入到你的Bash配置文件中去: # These lines will print a message if the noclobber option is set: ...
问Bash Shell sftp在创建之前检查目录是否存在EN本文主要讲述如何使用Shell脚本判断HDFS文件或目录是否存在，...