since google took too long to find the right answer ...

needed to do

    arg_dup = ARGV[ 0 ].dup



Since Ruby 2.3 recommended method is to [use the unary plus operator][1], it will return a duplicated mutable string, if a string is frozen.

`+arg`


  [1]: http://ruby-doc.org/core-2.3.0/String.html#method-i-2B-40

I&#39;m creating a simple back-end app through which the user can create/update/delete database rows (in this case, job listings).

When it comes time for the user to edit an existing listing, I&#39;m trying to pre-fill most of the HTML form with the data from that existing row. I&#39;ve done this sucessfully for text inputs using the &quot;value&quot; property, and with selects using a bit of php in each option tag: if([conditionforoption]){echo&#39;selected&#39;}.

The input type that I&#39;m having trouble pre-filling is the textarea... any thoughts on how to get the existing data (a long varchar string) to be present in the textarea input when the user loads the page?

I&#39;m trying to stay away from a javascript solution if at all possible, but I&#39;ll use it if necessary.

How can I &quot;pre-fill&quot; the value of a textarea in an HTML form?

I&#39;d like to embed the text of short python scripts inside of a bash script, for use in say, my `.bash_profile`. What&#39;s the best way to go about doing such a thing?

The solution I have so far is to call the python interpreter with the `-c` option, and tell the interpreter to `exec` whatever it reads from `stdin`. From there, I can build simple tools like the following, allowing me to process text for use in my interactive prompt:

    function pyexec() {
        echo &quot;$(/usr/bin/python -c &#39;import sys; exec sys.stdin.read()&#39;)&quot;
    }
    
    function traildirs() {
        pyexec &lt;&lt;END
    trail=int(&#39;${1:-3}&#39;)
    import os
    home = os.path.abspath(os.environ[&#39;HOME&#39;])
    cwd = os.environ[&#39;PWD&#39;]
    if cwd.startswith(home):
        cwd = cwd.replace(home, &#39;~&#39;, 1)
    parts = cwd.split(&#39;/&#39;)
    joined = os.path.join(*parts[-trail:])
    if len(parts) &lt;= trail and not joined.startswith(&#39;~&#39;):
        joined = &#39;/&#39;+joined
    print joined
    END
    }

    export PS1=&quot;\h [\$(traildirs 2)] % &quot;

This approach smells slightly funny to me though, and I&#39;m wondering what alternatives to doing it this way might be. 

My bash scripting skills are pretty rudimentary, so I&#39;m particularly interested to hear if I&#39;m doing something silly from the bash interpreter&#39;s perspective.


embedding short python scripts inside a bash script

Got 

&gt; ... &#39;[]=&#39;: can&#39;t modify frozen string (TypeError)

when trying to modify what I thought was a copy of ARGV[0].

Same results for each of

    arg = ARGV[ 0 ]
    arg_cloned = ARGV[ 0 ].clone
    arg_to_s = ARGV[ 0 ].to_s

    arg[ &#39;x&#39; ] = &#39;y&#39;
    arg_cloned[ &#39;x&#39; ] = &#39;y&#39;
    arg_to_s[ &#39;x&#39; ] = &#39;y&#39;


Ruby - can&#39;t modify frozen string (TypeError)

Got
> ... '[]=': can't modify frozen string (TypeError)
when trying to modify what I thought was a copy of ARGV[0].
Same results for each of
<pre><code class="hljs language-css">arg = ARGV[ 0 ]
arg_cloned = ARGV[ 0 ].clone
arg_to_s = ARGV[ 0 ].to_s

arg[ 'x' ] = 'y'
arg_cloned[ 'x' ] = 'y'
arg_to_s[ 'x' ] = 'y'
</code></pre>

Inspired by &quot;https://stackoverflow.com/questions/59895/can-a-bash-script-tell-which-directory-it-is-stored-in&quot;, what&#39;s the Ruby way to do this?


Can a Ruby script tell what directory it’s in?

Ruby/Rails does lots of cool stuff when it comes to sugar for basic things, and I think there&#39;s a very common scenario that I was wondering if anyone has done a helper or something similar for.

       a = Array.new(5, 1)
    
       a.each_with_index do |x, i|
         if i == 0
           print x+1
         elsif i == (a.length - 1)
           print x*10
         else
            print x
         end
       end

Pardon the ugliness, but this gets at what one might want... is there a ruby way to do something to the first and last of a loop?

**[EDIT]** I think ideally this would be an extension on Array with parameters (array instance, all elements function, &lt;optional&gt; first elements function, &lt;optional&gt; last elements function)... but I&#39;m open to other thoughts.

Magic First and Last Indicator in a Loop in Ruby/Rails?

I have an array of hashes, @fathers.

    a_father = { &quot;father&quot; =&gt; &quot;Bob&quot;, &quot;age&quot; =&gt;  40 }
    @fathers &lt;&lt; a_father
    a_father = { &quot;father&quot; =&gt; &quot;David&quot;, &quot;age&quot; =&gt;  32 }
    @fathers &lt;&lt; a_father
    a_father = { &quot;father&quot; =&gt; &quot;Batman&quot;, &quot;age&quot; =&gt;  50 }
    @fathers &lt;&lt; a_father 

How can I search this array and return an array of hashes for which a block returns true?

For example:

    @fathers.some_method(&quot;age&quot; &gt; 35) #=&gt; array containing the hashes of bob and batman

Thanks.



How do I search within an array of hashes by hash values in ruby?

I am new to Ruby.  I&#39;m looking to import functions from a module that contains a tool I want to continue using separately.  In Python I would simply do this:

    def a():
        ...
    def b():
        ...
    if __name__ == &#39;__main__&#39;:
        a()
        b()

This allows me to run the program or import it as a module to use `a()` and/or `b()` separately.  What&#39;s the equivalent paradigm in Ruby?

`if __name__ == &#39;__main__&#39;` equivalent in Ruby

What is Rack middleware in Ruby? I couldn&#39;t find any good explanation for what they mean by &quot;middleware&quot;.


Content Type	Original Author	Original Content on Stackoverflow
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Solution 1 - Ruby	Straff	View Answer on Stackoverflow
Solution 2 - Ruby	DirtyF	View Answer on Stackoverflow

Ruby - can't modify frozen string (TypeError)

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embedding short python scripts inside a bash script

How can I "pre-fill" the value of a textarea in an HTML form?

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