check if the particular file exists or not. The existence of the file can be checked using the file test operators with the “test” command or without the “test” command. The purposes of different types of file test operators to check the existence of the file are shown in this ...
When writing Shell scripts, you may find yourself in a situation where you need to perform an action based on whether a file exists or not. In Bash, you can use the test command to check whether a file exists and determine the type of the file....
When you are working on a shell script in bash, there are cases where you want to check if a particular file exists (or does not exist) in a directory, and then perform an action based on the condition. In bash, there are several ways to check whether or not a file exists in bash...
exists and [ FILE1 -ot FILE2 ] 如果 FILE1 比 FILE2 要老, 或者 FILE2 存在且 FILE1 不存在则为真。 [ FILE1 -ef FILE2 ] 如果 FILE1 和 FILE2 指向相同的设备和节点号则为真。 [ -o OPTIONNAME ] 如果 shell选项 “OPTIONNAME” 开启则为真。 [ -z STRING ] “STRING” 的长度为零则为...
But here, we used the which command, which is used to locate the executable file that would be executed if a command is run. It is also used to determine if the specified command exists. In the above code, the if statement checks if the wget command exists by running the command which...
Check if file does not exists if [ ! -f /tmp/users.txt ]; then echo "File not found" fi Parameterize file name in script to check if file doesn’t exist filecheck.sh #!/bin/bash FILEPATH=$1 if [ ! -f "$FILEPATH" ]; then ...
test -f /etc/fstab ## true if a regular file test -h /etc/rc.local ## true if a symbolic link [ -x "$HOME/bin/hw" ] ## true if you can execute the file [[ -s $HOME/bin/hw ]] ## true if the file exists and is not empty 整数测试 整数之间的比较使用-eq、-ne、-gt...
is readable-s FILE_NAM # TrueifFILE_NAM existsandisnotempty-w FILE_NAM # TrueifFILE_NAM has write permission-x FILE_NAM # TrueifFILE_NAM is executable#字符串测试操作-z STRING # TrueifSTRING is empty-n STRING # TrueifSTRING isnotemptySTRING1...
/bin/bash # declare STRING variable STRING="Hello World" #print variable on a screen echo $STRING Navigate to a directory where your hello_world.sh is located and make the file executable: $ chmod +x hello_world.sh Now you are ready to execute your first bash script:...
if [ -f /var/log/messages ] then echo "/var/log/messages exists." fi echo echo "...done." 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: ...