I have a bit of code that will add an amount to an array and then print
that back on the right line of a text file. Its basically a recorded
bidding system. However, is it possible to add the file location for
File.open(’/path/to/file/’) dynamically rather than having to create a
new bid.cgi file for every single bid. I have 12 items which need to be
edited so essentially it needs to be able to change to 12 file names and
locations.
Thanks
Adam K
(Will post code if needed)
On Thu, Jan 17, 2013 at 3:53 PM, Adam K. [email protected]
wrote:
I have a bit of code that will add an amount to an array and then print
that back on the right line of a text file. Its basically a recorded
bidding system. However, is it possible to add the file location for
File.open(‘/path/to/file/’) dynamically rather than having to create a
new bid.cgi file for every single bid. I have 12 items which need to be
edited so essentially it needs to be able to change to 12 file names and
locations.
I’m not sure what problems you are having exactly, File.open can
receive a variable:
a = “file.txt”
File.open(File.join(“home”,“jesus”,“temp”,a), “w”) do |f|
#do your stuff
end
You can choose values for a and do the same stuff in different files.
BTW, as you mention cgi I assume this is going to be published on the
internet. I advise you to be careful about how you choose the files
for security reasons. For example, don’t let the files be anywhere in
your filesystem or you might compromise your server.
Jesus.
Hi,
Yeah I have a File.open function opening, a file called david.txt. In
that file it has a few bit of information. One of those pieces of
information is price. £0.00. The code needs to open the text file
david.txt, add it to an array and then save it, displaying the new
price. I can do this fine, but I basically want to have it that when the
user inputs their bid via a form input and submit, it opens the file
dynamically, father than having 12 different bid.cgi files for each text
file.
Hope this explains it a bit better the code is as follows:
#Displaying information
#!/media/Apache/ruby/bin/ruby
#!/usr/local/bin/ruby
#encoding: utf-8
puts “Content-type: text/html\n\n”
#Adds information from david.txt to an array
f = File.open("…/logs/david.txt")
a = f.readlines
puts “”
puts “”
puts “David Quetta - Nothing But the Beat”
puts “”
puts “”
puts “
Name :”
puts a[0]
puts “
Description :”
puts a[1]
puts “
Price :£”
puts a[2]
puts “
Item Number :”
puts a[3]
puts “
#Adding bid (its broken at this stage)
#!/media/Apache/ruby/bin/ruby
#!/usr/local/bin/ruby
#Adds information from david.txt to an array
f = File.open("…/logs/david.txt")
a = f.readlines
#Sets params for form data
require ‘cgi’
cgi = CGI.new()
bid = cgi.params[‘bid’]
a[2] = bid
puts “Content-type: text/html\n\n”
puts “”
puts “<meta http-equiv=“REFRESH”
content=“4;url=/cgi-bin/david.cgi”>”
puts “Thank you”
puts “”
puts “”
puts “
Thank you for your bid, it will now be logged and you will be
redirected now.
In the bid.cgi which is the second file, the f = File.open needs to be
changed automatically.
Thanks
Adam k
On 17.01.2013 15:31, Adam K. wrote:
a = f.readlines
f.puts a[0]
puts “Thank you”
puts “”
puts “”
puts “Thank you for your bid, it will now be logged and you will
”
be
redirected now.
puts “”
puts “”
If I understand your question correctly (and I’m not 100% sure I do!),
one simple way to achieve what you want with your existing code would be
to have a hidden form element in the submit page that your second script
reads and then determines which of your 12 files to edit. E.g: (WARNING
UNTESTED!) Your first script looks like:
#Displaying information
#!/media/Apache/ruby/bin/ruby
#!/usr/local/bin/ruby
#encoding: utf-8
puts “Content-type: text/html\n\n”
#Adds information from david.txt to an array
f = File.open("…/logs/david.txt")
a = f.readlines
puts “”
puts “”
puts “David Quetta - Nothing But the Beat”
puts “”
puts “”
puts “
Name :”
puts a[0]
puts “
Description :”
puts a[1]
puts “
Price :£”
puts a[2]
puts “
Item Number :”
puts a[3]
puts “
And your second script something like:
#!/media/Apache/ruby/bin/ruby
#!/usr/local/bin/ruby
files = {‘David’ => ‘…/logs/david.txt’}
#Sets params for form data
require ‘cgi’
cgi = CGI.new()
bid = cgi.params[‘bid’]
item = cgi.params[‘item’]
#Adds information from david.txt to an array
f = File.open(files[item])
a = f.readlines
a[2] = bid
File.open(files[item], ‘w’) { |f|
f.puts a[0]
f.puts a[1]
f.puts a[2]
f.puts a[3]
}
puts “Content-type: text/html\n\n”
puts “”
puts “<meta http-equiv=“REFRESH”
content=“4;url=/cgi-bin/david.cgi”>”
puts “Thank you”
puts “”
puts “”
puts “
Thank you for your bid, it will now be logged and you will be
redirected now.
I assume this is a learning exercise, but if not you probably want to
start thinking about web frameworks and a database backend as this
system doesn’t really scale in any sensible way. And the puts “”
bits burn my eyes.
EDIT:
Complete working code for adding bid to a file:
#!/media/Apache/ruby/bin/ruby
#!/usr/local/bin/ruby
#Adds information from david.txt to an array
f = File.open("…/logs/david.txt")
a = f.readlines
#Sets params for form data
require ‘cgi’
cgi = CGI.new()
bid = cgi.params[‘bid’]
a[2] = bid
File.open(’…/logs/david.txt’, ‘w’) { |f|
f.puts a[0]
f.puts a[1]
f.puts a[2]
f.puts a[3]
}
puts “Content-type: text/html\n\n”
puts “”
puts “<meta http-equiv=“REFRESH”
content=“4;url=/cgi-bin/david.cgi”>”
puts “Thank you”
puts “”
puts “”
puts “
Thank you for your bid, it will now be logged and you will be
redirected now.
Yeah Its for a uni prodject and I have never used Ruby before so its a
massive learning curve. I know it looks horrible too 
Thanks for the help ill have a look at the code you changed but i
believe this is what im looking for.
Adam K
On Thu, Jan 17, 2013 at 9:03 AM, Alex G.
[email protected] wrote:
I assume this is a learning exercise, but if not you probably want to start
thinking about web frameworks and a database backend as this system doesn’t
really scale in any sensible way. And the puts “” bits burn my eyes.
+1 to that. This whole thing is so painfully un-Rubyish. And this –
#Displaying information
#!/media/Apache/ruby/bin/ruby
#!/usr/local/bin/ruby
#encoding: utf-8
is just nonsensical. A shebang line must be the first line of a file,
and having 2 different ones makes no sense at all.
Yeah thanks Alex for all your help!
After looking at your code, it worked fine. Brought up the correct
information and also enabled me to bid on an item. However, I tried
adding an if function too look something like this:
if item == ‘david’
files = {‘david’ => ‘…/Ablums/david.txt’}
end
As you can see, I’ve changed the location of the files and also the
value from the form is also lowercase d for david.
The reason I am trying to do this is that I have 12 text files which
hold different information about music Albums, I need a function go do
something like this:
if item == form value
change files to {‘david’ => ‘…/Albums/david.txt’}
else
if item == form value
change files to {‘asher’ => …/Albums/asher.txt’}
end
(sorry for the pseudo)
So I need this function to go through 12 different item names and
depending on which one was submitted through the form it needs to open a
different file.
I keep receiving this error from my error_logs:
`initialize’: can’t convert nil into String (TypeError), referer:
http://localhost:10000/cgi-bin/david.cgi
on line 14 where this is occuring, the line is File.open(files[item])
So basically it seems that my function is being skipped to line 14 then
it can’t find the ‘files’ and stops working. I know this is alot of
writing and i appreciate the help alot. If you have any idea of what is
going I would love to know 
Adam K
Just a quick update have the whole thing put together using an else if
function but everytime I add a bid i get the error:
[Fri Jan 18 15:46:24 2013] [error] [client 127.0.0.1]
/media/Apache/apache2/cgi-bin/bid.cgi:38:in <main>': undefined method files’ for main:Object (NoMethodError), referer:
http://localhost:10000/cgi-bin/david.cgi
dont understand why its doing this!
On 18.01.2013 13:12, Adam K. wrote:
Yeah Its for a uni prodject and I have never used Ruby before so its
a
massive learning curve. I know it looks horrible tooThanks for the help ill have a look at the code you changed but i
believe this is what im looking for.Adam K
IMO, as part of a learning process, generating hand written html is
fine, good even: You’ll understand the fine details of what is happening
better, so when you do come to using a framework that abstracts the
details away you’ll a) be able to debug it when it breaks and b)
appreciate the convenience/beauty factor.
WOW! I did this to begin with then thought I was doing it wrong! How
stupid of me.
Have edited the code correctly and now getting an error for the
File.open(files[item) saying:
26:in `initialize’: can’t convert nil into String (TypeError), referer:
http://localhost:10000/cgi-bin/david.cgi
Will have a look around and see whats going on…
Thanks for you help!
For some reason, it doesnt think that item has been filled from the
Form.
However it has and yet its not working
Any ideas?
On 18.01.2013 14:28, Adam K. wrote:
As you can see, I’ve changed the location of the files and also the
if item == form value
I keep receiving this error from my error_logs:
going I would love to knowAdam K
I think there is a fundamental misunderstanding of the idea behind my
code. Instead of a series of hard-coded if/else statements don’t you
just need a single completely filled out ‘files’ Hash with separate
files for each album? E.g:
files = {‘david’ => ‘…/Albums/david.txt’,
‘asher’ => ‘…/Albums/asher.txt’,
‘snoop’ => ‘…/Albums/snoop.txt’,
‘kennyg’ => ‘…/Albums/kenny.txt’,
‘theknife’ => ‘…/Albums/theknife.txt’}
Then the
File.open(files[item])
line will open the correct file based on the item given.
Yeah sorry its been a long day of coding today.
The code does contain the second ] after item so it does read [item].
I will have a look, ive already output the item from the form and it
does contain a value so its not the form. Its more todo with the Hash.
ill write that if statement into my code and ill see what it outputs.
Thanks Joel 
Right ran the code saying that item is not a hash . Then inspecting the
item outputs:
[“david”]
This is correct as the hidden value is david and the hash outputs all of
the correct names which I have specified in the hash.
The only thing that i can see is that the item is in the format of
[“david”], would this be a problem when the has is looking for “david”
does it could the square brackets as part of the string?
Thanks
Adam k
“files[item” isn’t valid. “files[item]” would be valid code…
It’s case-sensitive, so maybe you have an uppercase string and you’re
trying to compare it to a lowercase one? You’d get “nil” if your hash
doesn’t contain the key you’re entering.
Test that the hash contains the string and fail with a descriptive error
if the conditions aren’t right. Like this:
if files[item].nil?
fail TypeError, “item is not in hash: #{item.inspect}\n#{files.keys}”
end
Possibly.
Try
puts item.class
With regard to the enormous sequence of puts, you might want to look
into this:
http://log.gmarik.info/2007/12/rubys-here-document-heredoc-mini.html
outputs: Array
So confused!
That’s not really an ideal solution, you should probably trace the
origin of “item” and find out why it’s giving you an array rather than a
string.
I suspect that replacing
cgi.params[‘item’]
with
cgi[‘item’]
would return a string, so that you don’t have to format your hash key as
an array.
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