From: Robert Klemme <shortcutter@...>
Date: 2013-04-29T00:42:45+09:00
Subject: Re: Store/Delete a string permanently in Ruby

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On Fri, Apr 26, 2013 at 2:11 PM, cynic limbu <lists@ruby-forum.com> wrote:

> Can you create a program in ruby that can store a string or delete and
> replace them permanently?
>
> Yes I know you can store and change a string that is stored in a
> variable by writing
>
> var1 = "Hello world"
> puts "The string of var1 is #{var1}, To change var1's string type in
> anything"
> var1 = gets.chomp
> print "The string has been changed successfully, The string now is
> #{var1}"
>
>
> But whenever you restart the program again the var1's value changes back
> to Hello world. How can you change or the var1's value or remove it
> permanently?


The most simple way is to store it in a file

$ ls -l data
ls: cannot access data: No such file or directory
$ ./read.rb
"Hello world"
"Hello world ."
$ ./read.rb
"Hello world ."
"Hello world . ."
$ ./read.rb
"Hello world . ."
"Hello world . . ."
$ ls -l data
-rw-r--r--+ 1 Robert None 17 Apr 28 17:41 data
$ cat data
Hello world . . .$ cat -n read.rb
     1  #!/usr/bin/ruby
     2
     3  file_name = ENV['HOME'] + "/data"
     4
     5  var1 = File.read(file_name) rescue "Hello world"
     6
     7  p var1
     8  var1 << " ."
     9  p var1
    10
    11  File.open(file_name, 'w') {|io| io.write(var1)}
    12

Kind regards

robert

-- 
remember.guy do |as, often| as.you_can - without end
http://blog.rubybestpractices.com/

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<div dir=3D"ltr"><br><div class=3D"gmail_extra"><br><br><div class=3D"gmail=
_quote">On Fri, Apr 26, 2013 at 2:11 PM, cynic limbu <span dir=3D"ltr">&lt;=
<a href=3D"mailto:lists@ruby-forum.com" target=3D"_blank">lists@ruby-forum.=
com</a>&gt;</span> wrote:<br>
<blockquote class=3D"gmail_quote" style=3D"margin:0px 0px 0px 0.8ex;border-=
left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;p=
adding-left:1ex">Can you create a program in ruby that can store a string o=
r delete and<br>

replace them permanently?<br>
<br>
Yes I know you can store and change a string that is stored in a<br>
variable by writing<br>
<br>
var1 =3D &quot;Hello world&quot;<br>
puts &quot;The string of var1 is #{var1}, To change var1&#39;s string type =
in<br>
anything&quot;<br>
var1 =3D gets.chomp<br>
print &quot;The string has been changed successfully, The string now is<br>
#{var1}&quot;<br>
<br>
<br>
But whenever you restart the program again the var1&#39;s value changes bac=
k<br>
to Hello world. How can you change or the var1&#39;s value or remove it<br>
permanently?<span class=3D""><font color=3D"#888888"></font></span></blockq=
uote><div><br></div><div style>The most simple way is to store it in a file=
</div><div style><br></div><div>$ ls -l data</div><div>ls: cannot access da=
ta: No such file or directory</div>
<div>$ ./read.rb</div><div>&quot;Hello world&quot;</div><div>&quot;Hello wo=
rld .&quot;</div><div>$ ./read.rb</div><div>&quot;Hello world .&quot;</div>=
<div>&quot;Hello world . .&quot;</div><div>$ ./read.rb</div><div>&quot;Hell=
o world . .&quot;</div>
<div>&quot;Hello world . . .&quot;</div><div>$ ls -l data</div><div>-rw-r--=
r--+ 1 Robert None 17 Apr 28 17:41 data</div><div>$ cat data</div><div>Hell=
o world . . .$ cat -n read.rb</div><div>=A0 =A0 =A01 =A0#!/usr/bin/ruby</di=
v><div>
=A0 =A0 =A02</div><div>=A0 =A0 =A03 =A0file_name =3D ENV[&#39;HOME&#39;] + =
&quot;/data&quot;</div><div>=A0 =A0 =A04</div><div>=A0 =A0 =A05 =A0var1 =3D=
 File.read(file_name) rescue &quot;Hello world&quot;</div><div>=A0 =A0 =A06=
</div><div>=A0 =A0 =A07 =A0p var1</div><div>
=A0 =A0 =A08 =A0var1 &lt;&lt; &quot; .&quot;</div><div>=A0 =A0 =A09 =A0p va=
r1</div><div>=A0 =A0 10</div><div>=A0 =A0 11 =A0File.open(file_name, &#39;w=
&#39;) {|io| io.write(var1)}</div><div>=A0 =A0 12</div><div>=A0<br></div></=
div>Kind regards</div><div class=3D"gmail_extra">
<br></div><div class=3D"gmail_extra">robert<br clear=3D"all"><div><br></div=
>-- <br>remember.guy do |as, often| as.you_can - without end<br><a href=3D"=
http://blog.rubybestpractices.com/">http://blog.rubybestpractices.com/</a>
</div></div>

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