How to do string comparison and check if a string equals to a value? 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...
Since the first argument to this script was4, and 4 is equal to 4, the code within the IF statement was executed. You can pair IF statements with ELSE statements. An ELSE statement only runs if the conditional expression being evaluated by the IF statement is false. Let’s create a simp...
Knowing how conditionals work in bash open up a world of scripting possibilities. We’ll learn the basic syntax, including if, else, and elif. Then we'll look at a few of the "primary" operators you can leverage in a conditional statement such as = for string equality, -eq for numeric...
There is three loop constructs available in bash: for-loop, while-loop, and until-loop. All the bash loop constructs have a return status equals to the exit status of the last command executed in the loop, or zero if no command was executed. The For loop...
and elif. Then we'll look at a few of the "primary" operators you can leverage in a conditional statement such as = for string equality, -eq for numeric equality, and -e to check if a file exists. After that, we'll use conditional statements to create a function that asserts that ...
We’ll be checking whether 1 equals 2. If true, then the output will be “true”. Otherwise, the output will be “false”. $ test 1 -eq 2 && echo“true” || echo“false” Let’s break it down. test: The test command. 1: The first element for comparison. -eq: Comparison ...
filename="bash.string.txt" echo ${filename#*.} echo ${filename%.*} $ ./shortest.sh After deletion of shortest match from front: string.txt After deletion of shortest match from back: bash.string In the first echo statement substring ‘*.’ matches the characters and a dot, and # st...
For example, we can check if the file has a .jpg extension using a conditional statement: $ if [[ "file.jpg" = *.jpg ]]; then echo "is jpg"; fi is jpg There’s also an extended matching system called “extended globbing”. It enables us to constraint wildcards to specific patte...
“echo” statement using the “-n” flag to test if the next string to be inserted in the statement is some character or is empty. The character “*” has been added as a value to be multiplied by the iteration number. The first “for” loop ends and another “echo” statement will...
If the statement is true, the code is executed. if statements in bash script use square brackets for the logical condition and also have support for else and elif (else if) branches. Bash supports standard programming language conditional operators such as equals (==), not equals (!=), ...