How can I save a string with hexadecimal values to environment variable and later retrieve it in ruby?
Currently, when I retrieve it using ENV[] it will return with slashes escaped. So it retrieves like "\\x12\\x33". How can I make it so that when the environment variable is retrived from ruby then it returns the same exact string "\x12\x33".
Suppose I have a string with hexadecimal characters such as
s = "\x12\x33"
I appreciate any help! Thanks!
TEST='\x34\x33' ruby -e "
puts ENV['TEST'].split('\\x')[1..-1].map(&:to_i).map(&:chr)"
#⇒ "
# !
ok i solved this by first writing the binary to file and then reading it.
Writing
data = "\x12\x33"
File.open("data.bz2", "wb") do |f|
f.write(data)
end
Reading
file = File.open("data.bz2", "rb")
contents = file.read
print contents
Related
I am trying to create a new file and then write some content to it just to create a basic backup of a template.
When I log out the values of filename and file_content they are correct, but when I send the data all I get is a file named after the method (download_include) and a fixnum inside the file, the last one made was 15.
# POST /download_include/:id
def download_include
#include = Include.find(params[:id])
version_to_download = #include.latest_version_record
filename = "#{version_to_download.name}"
file_content = "#{version_to_download.liquid_code.to_s}"
file = File.open(filename, "w") { |f| f.write (file_content) }
send_data file
end
I also tried send_file but that produces the error
no implicit conversion of Fixnum into String
I also tried to just write dummy values like below, and it still produced a file named after the method with a fixnum inside it.
file = File.open("DOES THIS CHANGE THE FILENAME?", "w") { |f| f.write ("FILE CONTENT?") }
I feel I am missing something obvious but I cannot figure it out after looking at many examples here and in blogs.
If you don't end along the filename as an option for send_data, it defaults to the method name.
Secondly, the download wants to read the data from a buffer. My guess is your syntax is just sending a file handle.
Try this...
send_data(file.read, filename: filename)
Or skip the intermediate file and try...
send_data(version_to_download.liquid_code.to_s, filename: filename)
I want to generate a tar from a buch of files.
out_file = File.new('some.tar', 'w')
tar = Gem::Package::TarWriter.new out_file
attachments = #Array of attachment objects
attachments.each{|a|
file = Attachment.new(a).read_file #returns a String
file.force_encoding('UTF-8')
tar.add_file_simple( a[:filename], 777, file.length) do |io|
io.write(file)
end
}
Gem::Package::TarWriter::FileOverflow - You tried to feed more data
than fits in the file.
Has anyone an idea why this happens and how to fix it?
String#length returns the number of characters in the String. Since a UTF-8 character can be represented by more than a single byte, the bytesize of a string is usually larger.
The TarWriter now expects the file size to be given in bytes. Thus, if you use anything else than plain ascii characters in your file, it will overflow.
To solve this, you should thus pass file.bytesize to the add_file_simple method instead of file.size.
I'm having trouble calling image.write with MiniMagick on a decoded base64 image in Rails. Every line seems to be working properly except for image.write. The code below is in my Rails API ImageController, which my React frontend is hitting through a POST request with the encoded image.
def create
uploaded_io = params["image_io"]["base64"] # base64 string + metadata
metadata = uploaded_io.split(',/')[0] + "," # "data:image/jpeg;base64,"
filetype = metadata.split("/")[1].split("base64")[0][0...-1] # "jpeg"
base64_string = uploaded_io[metadata.size..-1] # base64 string w/o metadata
blob = Base64.decode64(base64_string)
image = MiniMagick::Image.read(blob)
image.write `#{Time.new.to_i}.#{filetype}`
storage = Google::Cloud::Storage.new(
project_id: ENV['GOOGLE_CLOUD_PROJECT'],
credentials: JSON.parse(File.read('config/google_cloud_credentials.json'))
)
bucket = storage.bucket "auto-stock-189103.appspot.com"
bucket.create_file image,`test/#{Time.new.to_i}.jpg`
end
I added comments to the first few lines in the code describing their value. base64_string was too long to comment, so here is its value:
"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"
Testing it here renders the correct image (a red square), but when I run the image.write line it returns the following error:
bin/rails: No such file or directory - 1513397345.jpeg
*** NoMethodError Exception: undefined method `write' for nil:NilClass
nil
Here's the return value of image = MiniMagick::Image.read(blob) for reference:
#<MiniMagick::Image:0x00007f9ba76ba1f8 #path="/var/folders/pf/xhvv11092_j08hw47q6rt9z80000gn/T/mini_magick20171215-26353-l2lcyu", #tempfile=#<Tempfile:/var/folders/pf/xhvv11092_j08hw47q6rt9z80000gn/T/mini_magick20171215-26353-l2lcyu (closed)>, #info=#<MiniMagick::Image::Info:0x00007f9ba76ba1d0 #path="/var/folders/pf/xhvv11092_j08hw47q6rt9z80000gn/T/mini_magick20171215-26353-l2lcyu", #info={}>>
Ultimately, my goal is to upload the image to Google Cloud so please let me know if there's a better way to go about this. I'm following this answer from a similar question, which is why I have it structured this way.
I think your problem is that you're using backticks where you mean to use double quotes:
image.write `#{Time.new.to_i}.#{filetype}`
# ----------^----------------------------^
Backticks will attempt to execute their contents in the shell. You don't have an executable file named 1513397345.jpeg (which is what #{Time.new.to_i}.#{filetype} evaluates to) so you get an error.
You just want to use plain old double quotes to get the string interpolation you're expecting:
image.write "#{Time.new.to_i}.#{filetype}"
and again a few lines below that:
bucket.create_file image, "test/#{Time.new.to_i}.jpg"
Furthermore, you probably want to store that filename in a variable because Time.new.to_i isn't guaranteed to be the same in both invocation:
name = "#{Time.new.to_i}.#{filetype}
image.write name
#...
bucket.create_file image, name
In my Rails app, I managed to stream large CSV files directly from Postgres based on solutions mentioned in this SO post. My working code looks somewhat like so:
query = <A Long SQL Query String>
response.headers["Cache-Control"] = "no-cache"
response.headers["Content-Type"] = "text/csv; charset=utf-8"
response.headers["Content-Disposition"] =
%(attachment; filename="#{csv_filename}")
response.headers["Last-Modified"] = Time.now.ctime.to_s
conn = ActiveRecord::Base.connection.raw_connection
conn.copy_data("COPY (#{query}) TO STDOUT WITH (FORMAT CSV, HEADER TRUE, FORCE_QUOTE *, ESCAPE E'\\\\');") do
while row = conn.get_copy_data
response.stream.write row
end
end
response.stream.close
end
Some of the columns (VARCHAR) being queried have values as either English or Chinese strings. The CSV file resulting from the above code doesn’t show the Chinese characters as is. Instead, I get something like this:
大大 文文
Am I supposed to change the way I’m using the copy_data function, or is there something I could do to the CSV file to solve this? I’ve tried saving the file as UTF-8 .txt file, as well as trying the convert_to function mentioned in the copy_data documentation, but to no avail.
This depends of the original encoding included in the CSV file.
Do this on Linux :
file -i you_file
Are you sure it's not UTF-16 or GB 18030 ?
And also in what kind of encoding is setup your database ?
do a \l in psql to see this.
So it boiled down to my MS Excel not being able to render the Chinese chars correctly. On MacOS, opening the same .csv file using the Numbers app (or even Atom, for that matter) resolved this issue for me.
I have the following string that needs to be replaced by an empty character in rails. Followed many tutorials and docs. Please help me achieve this.
String:
/home/<someword>/dbdumps/backup.sql
To be replaced as:
backup
To get the file name from a path, I'd use File#basename
File.basename('/home/<someword>/dbdumps/backup.sql', '.sql')
#=> 'backup'
if "someword" is the only thing that changes you dont even need regex.
Assume
path = "/home/<someword>/dbdumps/backup.sql"
then
path.split("/").last.split(".").first
returns
=> "backup"
The easiest solution would be a gsub (string substitution) like so:
string = "home/<someword>/dbdumps/backup.sql"
new_string = string.gsub(%r{home/(.*)/dbdumps/backup.sql}, 'backup' )
This is a simple example of string substitution.
In a rails app i do a Net:SSH:start( ) and run ssh.exec!('ls /home//dbdumps/.sql'). I am ?sending the output to a string and then i have to display the list of the files. For that I am taking the output into a string and trying to do a gsub. Is this the right approach?
I would not consider it pretty (naive code, no error checking, loops with requests) but something like this could do the job for you. It depends if you want to end up with just the backup names or the full path.
ssh.exec!("ls -l /home/") do |channel, stream, data|
directories << data if stream == :stdout
end
directories.each do |dir|
ssh.exec!("ls -l /home/" + dir + "dbdumps") do |channel, stream, data|
backup_names << /home/" + dir + "/" + data if stream == :stdout
end
end
hope this helps