In this method, I will be using the-nflag to check whether the variable is empty or not. Here's the simple script which will tell me whether the variable is empty or non-empty: #!/bin/bash variable="" if [ -n "$variable" ]; then echo "Variable is not empty." else echo "Vari...
In this bash script example, we first set the filename, the size_threshold variable and then check if any file exists with the given name using the -e option. If it exists, we use the wc command to get the file size in bytes and store it in the file_size variable. Next, we check...
If the $count variable is zero, the grep output was empty, passed to the wc-1 because the pattern was not matched. The script then outputs the message No match found. to the console using the echo command. That’s all about Bash check if grep result is empty. Was this post helpful?
Here the“-eq”operator is used to check if the“$#”variable is equal to zero or not and if the “$#” variable is equal to zero, the script will display an error message and exit with a status code of 1. Otherwise, the script will continue executing, below I have provided and i...
How to check if a string is in an array? How to use the Bash ternary operator? How to negate an if condition in a Bash if statement? (if not command or if not equal) How to use the BASH_REMATCH variable with the Regular Expression Operator =~?
Check to see if a variable is empty or not Create a new bash file, named, and enter the script below. The script above stores the first command-line argument in a variable and then tests the argument in the next statement. This script will print the first argument because it is not em...
Use the if-else statement with the -v option to check if an environment variable is set in bash. The echo command in the if block will be executed if the will
empty_array=()if[${#empty_array[@]}-eq0];thenecho"Array is empty"elseforiin"${empty_array[@]}"doecho"Processing item:$i"donefi# Output:# Array is empty Bash Copy In this example, we first check if the length of the array is 0, which indicates that the array is empty. If it...
其次,Shell 是一个命令解释器,解释用户输入的命令。它支持变量、条件判断、循环操作等语法,所以用户可以用 Shell 命令写出各种小程序,又称为脚本(script)。这些脚本都通过 Shell 的解释执行,而不通过编译。 最后,Shell 是一个工具箱,提供了各种小工具,供用户方便地使用操作系统的功能。
Using a "do while" loop in bash scripting is simple. Here, ‘-le’ keywords indicate the "less than or equal" sign of a normal programming language. The following script will run until the variable's value is greater than five. #!/bin/bash echo "Do while loop example" a=1 while [...