Menu
I want to create a Bash file that returns a value. Meaning, in script script_a.bash I have a certain calculation, and script script_b.bash will call it.
script_a.bash:
return $1*5
script_b.bash:
a_value=./script_a.bash 3
when a_value will be 15.
I read a little bit about that, and saw that there's no "return" in bash, but something like this can be done in functions using "echo". I don't want to use functions, I need a generic script to use in multiple places.
Is it possible to return a value from a different script? Thanks!
931
Return Values Unlike functions in “real” programming languages, Bash functions don't allow you to return a value when called. When a bash function completes, its return value is the status of the last statement executed in the function, 0 for success and non-zero decimal number in the 1 - 255 range for failure.
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.
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.
Use command substitution to capture the output of echo, and use arithmetic expression to count the result:
script_a.bash:
echo $(( $1 * 5 ))
script_b.bash
a_value=$( script_a.bash 3 )
Don't use return or exit, as they're for indicating the success/failure of a script, not the output.
Write your script like this:
#!/bin/bash
echo $(( $1 * 5 ))
Access the value:
a_value=$(./script_a.bash 3)
That is, use a $(command substitution) in the consuming code to capture the output of the script.
45
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
