I am not using carrierwave or paperclip for my file upload. I want to find out the file extension and the size in bytes of a file that the user has uploaded? Any ideas on how I can achieve this?
File.size(doc.filename)
Just throw the name of the file into the curly brackets and you should be set.
If you want KB/MB use:
number_to_human_size(File.size(doc.filename))
EDIT:
You can use the exact path or Pathname
1.9.3p125 :005 > x=Pathname.new("/usr/bin/ruby")
=> #<Pathname:/usr/bin/ruby>
1.9.3p125 :006 > File.size(x)
=> 5488
For extension:
File.extname("test.rb") #=> ".rb"
params[:file].size
File.extname(params[:file].original_name)
or params[:file].original_name.match(/\.(\S*)$/).try(:"[]",1)
You can use Ruby's File class methods.
File.size
File.extname
Related
How do I create a checksum (MD5, sha512, whatever) of a file when I upload it, so that when I download (using cache_stored_file!), I can verify that it is indeed the original file that was uploaded?
The Ruby Digest module can help with this.
One way solution would be to read the file on upload and assign it a unique digest with a before_create callback. I would add it as a column on the file table in your database.
Here's some output from IRB to show how it would work:
2.2.2 :001 > require 'digest'
=> true
2.2.2 :002 > f = File.read 'test.rb'
=> "Original content\n"
2.2.2 :003 > Digest::SHA256.hexdigest(f)
=> "646722e7ee99e28d618142b9d3a1bfcbe2196d8332ae632cc867ae5d1c8c57b5"
# (... file modified ...)
2.2.2 :004 > f = File.read 'test.rb'
=> "Original content with more content\n"
2.2.2 :005 > Digest::SHA256.hexdigest(f)
=> "c29f2f77c0777a78dbdf119bf0a58b470c098635dfc8279542e4c49d6f20e62c"
You can use this digest in your download method to check the integrity of the file. If you read the file again, produce a digest, and it matches the original digest, you can be confident the file hasn't been altered since it was uploaded.
Ruby Digest Module
md5 = Digest::MD5.file('path_to_file').hexdigest
This would read file in blocks and avoid reading the whole file in RAM which is done in File.read()
For SHA checksum
Digest::SHA2.hexdigest( File.read("/path/to/my/file.txt") );
OR
Digest::SHA2.file(myFile).hexdigest
=> "fa5880ac744f3c05c649a864739530ac387c8c8b0231a7d008c27f0f6a2753c7"
More details for SHA checksum generation SHA Checksum
I'm uploading my images with Carrierwave and Fog to S3. On the upload I also create a thumbnail version of the image:
version :thumb do
process :resize_to_limit => [90, 80], if: :is_resizable?
end
Now I need a method to check if thumbnail version exists.
The Documentation lists the exists? method. This actually works, if I want to check the existence of the original version:
asset.file.exists? # => true
But when I use the "thumb" version like this:
asset.url(:thumb).file.exists?
it get:
undefined method 'exists?' for #<String:0x007fcd9f9d9620>:
Use this:
asset.thumb.file.exists?
instead of: asset.url(:thumb).file.exists?
The correct answer is:
asset.file.thumb.file.exists?
where file = mounted_uploader and asset = model
I have some issue to allow users download file, which stored in PostgreSQL bytea escaped field (http://www.postgresql.org/docs/current/interactive/datatype-binary.html).
1.9.3p385 :023 > data = PG::Connection.unescape_bytea(m[:data])
=> "JVBERi0xLjMKJcTl8uXrp/Og0MTGCjQgMCBvYmoKPDwgL0xlbmd0aCA1IDAg\r\nUiAvRmlsdGVyIC9GbGF0ZURlY29kZSA+Pgpzd..."
1.9.3p385 :023 > data.encoding.name
=> "ASCII-8BIT"
1.9.3p385 :023 > data.bytesize
=> 3878164
But when I used "send_data" or "send_file" with tempfile, I getting file in invalid format (this is pdf file). It much bigger, than original and not opening by pdf readers.
This data in field is mime part of email. If I build raw email from all this parts (using boundary as separator), this email will contain valid pdf attachment.
How should I convert this data to bytes to allow user download this file separately?
See the following: http://rubyforge.org/tracker/index.php?func=detail&aid=27845&group_id=234&atid=967
The syntax is something like PGConn.unescape_bytea($field);
Depending on your version of pg, you may need to upgrade that gem
I am implementing in Ruby and i am running a project which reads a CSV file to add users.
but when i pick my file it just gives always the same error:
FasterCSV::MalformedCSVError in User importController#match
Illegal quoting on line 1.
my CSV file just exists of :
"RubenPersoon1","test","Bauwens","Ruben","rub#gmail.com",0
anyone who knows what can be wrong?
Try to upgrade your FasterCSV gem version. With the latest version it works:
FasterCSV.parse_line '"RubenPersoon1","test","Bauwens","Ruben","rub#gmail.com",0'
=> ["RubenPersoon1", "test", "Bauwens", "Ruben", "rub#gmail.com", "0"]
ruby-1.8.7-p352 :005 > FasterCSV.parse '"RubenPersoon1","test","Bauwens","Ruben","rub#gmail.com",0'
=> [["RubenPersoon1", "test", "Bauwens", "Ruben", "rub#gmail.com", "0"]]
Also, keep in mind that if you are on Ruby 1.9.2, FasterCSV is already included. Just require 'csv' and use the CSV class.
I am trying to check if a file exists in my rails application.
I am running ruby 1.8.6 and rails 2.1.2 with windows XP.
So, the problem is that the FileTest.exists? method doesn't seem to be working. I have simplified the code to this point :
if FileTest.exists?("/images/header.jpg")
render :text => "yes"
else
render :text => "no <img src='/images/header.jpg' />"
end
If I do that the system displays "no" and then includes the image that displays correctly because /images/header.jpg exists.
I tried FileTest.exists?, FileTest.exist?, File.exists?, File.exist? and nothing seems to be working.
What am I doing wrong ?
Thanks
I'm guessing it's because you're asking whether a file "header.jpg" exists in a directory "images" off of the root directory for your system (which on Windows I'd assume is "c:\"). Try putting the full path (from the filesystem root) to the "/images" directory rather than the URL path.
In particular, as pointed out by #Brian, you should use:
FileTest.exists?(RAILS_ROOT + "/images/header.jpg") # < rails 3.0
FileTest.exists?(Rails.root + "/images/header.jpg") # >= rails 3.0
Add RAILS_ROOT to the filename that you're checking before calling exists?