To check if a file is empty in a Bash script, you can use the "-s" test, which returns true if the file exists and has a size greater than zero. If you want to check if a file is empty, you would use the "!" (not or negate) operator with "-s" to negate the test. Here...
使用if语句和条件判断来检查一行是否为空。可以使用内置的变量$1来获取输入的行内容,然后判断该变量是否为空。示例代码如下: 代码语言:bash 复制 if [ -z "$1" ]; then echo "该行为空" else echo "该行不为空" fi 使用read命令读取输入的行内容,并判断是否为空。示例代码如下: 代码语言:bash 复制 read...
we are using the Bash instruction to run this Bash file, i.e., empty.sh. On execution, it returns “Empty” because the string “str” is initialized empty in the code, and the “then” part of the “if-else” statement has been executed so far. ...
All the code snippets are written in the MyScript.sh file, while the dummy.txt file contains some sample data we used in our scripts. Using -q Option with grep Use the -q option with grep to check if the grep command result is empty. Use -q Option with grep in MyScript.sh 1 2...
Check to see if a variable is empty or not Create a new bash file, named, and enter the script below. The script above stores the first command-line argument in a variable and then tests the argument in the next statement. This script will print the first argument because it is not em...
To check for a directory, replace the-foperator (which is used for checking if a file exists or not) with the-doperator. Example 1: A traditional approach Usually, the Bash built-in test operators are used in combination with the if conditional, like I demonstrated above. This has two ...
Check if a File Does not Exist Testing for a file returns0(true) if the file exists and1(false) if it does not exist. For some operations, you may want to reverse the logic. It is helpful to write a script to create a particular file only if it doesn’t already exist. ...
echo "File not found" fi Run Below command to check $ sh filecheck.sh /tmp/users.txt Check if file exists if [ -f /tmp/users.txt ]; then echo "File is exist" fi Expressions used with if The table below contains an overview of the so-called “primaries” that make up theTEST-COM...
Method 1: Theif [-f $file]Command Theif [ -f $file ]command is the equivalent of theif [ -d $directory ]command. They are pretty much the same, apart from the-fand-darguments: # Check if the 'my-file.txt' existsfile="/my-file.txt"if[ -f"$file"]then# The 'my-file.txt...
Check if Any File with Extension Exists inbash In all previousbashscript examples, the name of the file to check is pre-determined and known. What if you want to check if any file with a pattern (e.g., with a particular extension) exists? In that case, the name of file(s) to che...