How can we return value from ruby script?
#!/usr/bin/env ruby
a = "test"
a
How can we access the value of 'a' in Ubuntu terminal or java or c?
2 Answers
print your variable within ruby/python script, it can then be read from a shell script by example :
#!/bin/bash
ruby_var=$(ruby myrubyscript.rb)
python_var=$(python mypythonscript.py)
echo "$ruby_var"
echo "$python_var"
take care your ruby/python script only print this variable ( there are more complicated ways with named pipes by example for more interaction ).
1 Comment
philippe lhardy
thanks for +1 but my answer is out of subject given it is ruby. anyway , print in ruby or in python is the very same way.
If the value is an integer between 0 and 255, you can use the exit status
$ ruby -e 'var=42; exit var'
$ val=$?
$ echo $val
42
5 Comments
krunal shah
Is it possible to return the filename? Is there any other way to access the filename ?
Ajedi32
Note that an exit status of anything other than zero indicates an error.
glenn jackman
@krunalshah, you want philippe lhardy's answer to return a string from the child process to the shell.
glenn jackman
@Ajedi32, by convention yes. But since there are 256 possible exit status, it can convey more information than the binary "success|failure" status.
Ajedi32
@glennjackman Well, it's a little more than just convention. There are many commonly used Unix commands and processes into which this convention is heavily ingrained. For example, try running
set -e in your terminal, then try that example in your answer again. My point is, while you technically can use the exit status to return values from Unix commands, I wouldn't recommend using it in a real application for anything other than error codes.
$stdout. This will output to the standard output stream. You could also right the results to a file and parse the file after the script completes. Here is a nice little post on the subject of IO in Ruby