How do you write if/then statements in bash?

How do you write if/then statements in bash?

The if statement starts with the if keyword followed by the conditional expression and the then keyword. The statement ends with the fi keyword. If the TEST-COMMAND evaluates to True , the STATEMENTS gets executed. If TEST-COMMAND returns False , nothing happens; the STATEMENTS get ignored.

How do I use multiple if in bash?

Bash else-if statement is used for multiple conditions. It is just like an addition to Bash if-else statement. In Bash elif, there can be several elif blocks with a boolean expression for each one of them….Syntax of Bash Else If (elif)

1. if [ condition ];
2. then.
4. elif [ condition ];
5. then.
7. else.

What is option in if condition in shell script?

Options for IF statement in Bash Scripting If statement can accept options to perform a specific task. These options are used for file operations, string operations, etc. In this topic, we shall provide examples for some mostly used options. Example – if -z (to check if string has zero length)

When to use if else statement in shell?

The Shell expression is evaluated in the above syntax. If the resulting value is true, given statement (s) are executed. If the expression is false, then no statement will be executed. The above example can also be written using the if…else statement as follows −

What does the if.else.fi statement do?

The if…else…fi statement is the next form of control statement that allows Shell to execute statements in a controlled way and make the right choice. Syntax. The Shell expression is evaluated in the above syntax. If the resulting value is true, given statement(s) are executed. If the expression is false, then no statement will be executed.

How to do an IF statement from the result of an?

You can do more precise, yet simple, matching with awk. if netstat -lnp | awk ‘$4 ~ /:8080$/ && $7 ~ /java/ {exit (0)} END {exit (1)}’; then … To match the structure of your command more closely, the portable way of doing wildcard matching on a string in a shell is with the case construct.

When to use elif or else in shell script?

The elif (else if) condition tested if the variable was greater than or equal to 5, and the else statement handled the default output in case both the situations were false. But we can also test for multiple conditions and not be limited to just one.