Can bash function return values?

Bash functions, unlike functions in most programming languages do not allow you to return a value to the caller. To return values, you can set a global variable with the result, or use command substitution, or you can pass in the name of a variable to use as the result variable. …

How do you return a function in bash?

A bash function can return a value via its exit status after execution. By default, a function returns the exit code from the last executed command inside the function. It will stop the function execution once it is called. You can use the return builtin command to return an arbitrary number instead.

How do I return a string from a function in bash?

Bash function can return a string value by using a global variable. In the following example, a global variable, ‘retval’ is used. A string value is assigned and printed in this global variable before and after calling the function. The value of the global variable will be changed after calling the function.

How does a shell function return a value?

A function may return a value in one of four different ways:

Change the state of a variable or variables.
Use the exit command to end the shell script.
Use the return command to end the function, and return the supplied value to the calling section of the shell script.

How do you return an array from a function in bash?

This approach involves the following three steps:

Convert the array with ‘declare -p’ and save the output in a variable.
Use the echo builtin to pass the variable to a function or to pass it back from there.
Finally, recreate the array where it is passed to using the eval and the ‘declare -a’ builtins.

Can bash function access global variable?

Global variables They are visible and valid anywhere in the bash script. You can even get its value from inside the function.

What is Retval in shell script?

RETVAL is a system variable, and the -eq is a numeric test for equality. In this case, the return value again determines whether the test is true or false.

How do you return an array in bash?

Can shell script return string?

no, you can’t. You can set a global variable and call it “return”, as I see you do in your scripts.

How does a function return a value in Linux?

return command is used to exit from a shell function. It takes a parameter [N], if N is mentioned then it returns [N] and if N is not mentioned then it returns the status of the last command executed within the function or script. N can only be a numeric value.

What is eval in bash script?

eval is a builtin command of the Bash shell which concatenates its arguments into a single string. Then it joins the arguments with spaces, then executes that string as a bash command. Below is an example of how it works.

What is declare in bash?

‘declare’ is a bash built-in command that allows you to update attributes applied to variables within the scope of your shell. In addition, it can be used to declare a variable in longhand. Lastly, it allows you to peek into variables.

What are function return values?

A return is a value that a function returns to the calling script or function when it completes its task. A return value can be any one of the four variable types: handle, integer, object, or string. The type of value your function returns depends largely on the task it performs.

How to return string from Bash functions?

What is the function of a bash script?

A Bash function is essentially a set of commands that can be called numerous times . The purpose of a function is to help you make your bash scripts more readable and to avoid writing the same code repeatedly. Compared to most programming languages, Bash functions are somewhat limited.

Why does it return undefined values?

A method or statement also returns undefined if the variable that is being evaluated does not have an assigned value. A function returns undefined if a value was not returned. Be careful.