and we have initialized a string variable “v” with the value “Hello” in it. Then, we started the “if-else” statement to check whether the string is empty. For this, we have used the “-z” option within the square brackets...
The-zBash Operator The-zoperator returnstrueif a string variable is null or empty. How the use the-zBash Operator Afterdeclaring a string variable, use the-zoperator in anif statementto check whether a string is empty or not: MY_STRING="" if [ -z $MYSTRING ] then echo "String is ...
3. By comparing a variable to an empty string As the name suggests, in this method, I will be comparing the variable to an empty string using the[]operator. Here's the simple script: #!/bin/bash if [ "$variable" = "" ]; then echo "Variable is empty." else echo "Variable is ...
Variable is set: /root The -v option returns true if the given variable is set to an empty string, while it returns false if the provided variable is not declared. Use the if-else statement with the -z option to check if the length of the environment variable is 0 in bash. Length ...
bash command if a string is not empty examples of the check when DiskInternals can help you Are you ready? Let's read! Variables that are set and not empty A variable is either defined or not defined. However, when a variable is defined but has no value, then the variable is “Not ...
Check file types and compare values. Returns 0ifthe condition evaluates totrue, 1ifit evaluates tofalse. More information: https://www.gnu.org/software/bash/manual/bash.html#index-_005b_005b. - Testifa given variable is equal/not equal to the specified string: ...
Check file types and compare values. Returns 0 if the condition evaluates to true, 1 if it evaluates to false. More information: https://www.gnu.org/software/bash/manual/bash.html#index-_005b_005b. - Test if a given variable is equal/not equal to the specified string: ...
Now, we can implement the previous example of checking the existence of the"test"substring inside of the"This is a test string."string: Define the target string string="This is a test string."# Define the substringsubstring="test"# Check if the string contains the substringifecho"$string"...
The uses of the “-z” and “-n” option to test the string values using the “if” statement in Bash are shown in this tutorial. Using the “If -Z” Statement Sometimes, it is required to check if a string variable is empty or if it contains a string of zero length. There are...
If the $count variable is zero, the grep output was empty, passed to the wc-1 because the pattern was not matched. The script then outputs the message No match found. to the console using the echo command. That’s all about Bash check if grep result is empty. Was this post helpful?