Question

I would like to know how to pass single quotations as an argument in matlab. I am running a bash script that takes in a string of integers and creates an array from it. The bash program is like this:

read -a array <<< "$1"
for i in ${array[@]}
do
    echo $i
done

In the matlab GUI I want to test this function by doing this:

>> string = '1 2 3 4 5'
>> unix(['script.sh ' string]) 

and it gives

1

ans =

 0

but it does not print out the entire array! In bash if I do…

script.sh '1 2 3 4 5'

I get

1
2
3
4
5

My theory is that matlab is taking in the numbers, and the bash script is just reading the first argument ‘1’ into the array and printing it. So if I could somehow pass the string encapsulated by single quotations then it should work.

Answer 1

The issue is that Matlab’s unix() command only returns a status variable by default. You have to tell it to return the standard output as well, which is mentioned in the Matlab documentation for this function. The 0 value you are seeing is the status variable, and 0 means “success.”

What you want to do is:

 [status, result] = unix(['script.sh ' string]);
 disp(result);

Also, here is a link that helps explain string formatting in Matlab and includes the example of adding a single quote into a string. This is achieved by repeating the single quote symbol twice consecutively inside the string. So ”” yields ', because inside of the two outer single-quotes, I have placed two consecutive single quotes. This is different than using the double-quote keystroke on the keyboard, which produces a double quote. So you can write the array string as:

>> string = '''1 2 3 4 5'''
string = '1 2 3 4 5'