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 an
For example, to test if the file/tmp/test.logexists, run the following command: test -f /tmp/test.txtCopy The first line executes the test to see if the file exists. The second command,echo, displays the results. The result0means that the file exists, while1means no file was found....
Check if File Exists inbash The easiest way to check if a file exists is to use thetestcommand. With-f <file-name>option, thetestcommand returns true if the specified file exists. FILE=/etc/pam.conf if test -f $FILE; then echo "$FILE exists" fi Alternatively, you can use thebash'...
In order to check if a file exists in Bash using shorter forms, specify the “-f” option in brackets and append the command that you want to run if it succeeds. [[ -f <file> ]] && echo "This file exists!" [ -f <file> ] && echo "This file exists!" Using the example used ...
Using $1 to check if an input parameter exists in Bash Remember the positional parameters we discussed in the previous section. We can use the first $1 to check if any input parameters were passed, because if there were no input parameters, there$1would be no value in the positional param...
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...
7.1.1.3. 检查文件 第一个例子检查一个文件是否存在: anny ~> cat msgcheck.sh #!/bin/bash echo "This scripts checks the existence of the messages file." echo "Checking..." if [ -f /var/log/messages ] then echo "/var/log/messages exists." fi echo echo "...done." anny ~> ./msg...
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...
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...