How to return a value from a shell script in a perl script

Question

I have a perl script which requires a value from a shell script.

Following is the shell script (a.sh):

#!/bin/bash
return_value(){
$value =$(///some unix command)
return $value
}

Following is the perl script: ///

my $answer= `sh  a.sh`;
print("the answer is $answer");

But its not working. please help me out

Barmar · Accepted Answer · 2013-06-19 18:09:00Z

3

#!/bin/bash
return_value(){
  value=$(///some unix command)
  echo "$value"
}

return_value

You can't have any spaces around = in a shell variable assignment.
Don't put $ before the variable name that's the target of the assignment.
Perl's backticks capture the standard output of a command, so you have to echo the value (return sets the exit status of the function, it doesn't produce output).
You have to execute the function.
You should put $value in quotes in case it contains whitespace or filename wildcards.

answered Jun 19, 2013 at 18:09

Barmar

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Comments

Borodin · Accepted Answer · 2013-06-19 18:08:58Z

3

Just write

echo $value

in your bash code and the output will appear as the result of the backticks in the Perl code.

answered Jun 19, 2013 at 18:08

Borodin

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msw · Accepted Answer · 2013-06-19 18:09:14Z

1

Backqoutes substitute the stdout, not the return value (which is just an integer). If you used

echo $value

instead of return $value it would work as you expect. Simpler still would be

some unix command

as the single line in your bash script.

answered Jun 19, 2013 at 18:09

msw

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