SmarterCSV and file encoding issues in Ruby - ruby

I'm working with a file that appears to have UTF-16LE encoding. If I run
File.read(file, :encoding => 'utf-16le')
the first line of the file is:
"<U+FEFF>=\"25/09/2013\"\t18:39:17\t=\"Unknown\"\t=\"+15168608203\"\t\"Message.\"\r\n
If I read the file using something like
csv_text = File.read(file, :encoding => 'utf-16le')
I get an error stating
ASCII incompatible encoding needs binmode (ArgumentError)
If I switch the encoding in the above to
csv_text = File.read(file, :encoding => 'utf-8')
I make it to the SmarterCSV section of the code, but get an error that states
`=~': invalid byte sequence in UTF-8 (ArgumentError)
The full code is below. If I run this in the Rails console, it works just fine, but if I run it using ruby test.rb, it gives me the first error:
require 'smarter_csv'
headers = ["date_of_message", "timestamp_of_message", "sender", "phone_number", "message"]
path = '/path/'
Dir.glob("#{path}*.CSV").each do |file|
csv_text = File.read(file, :encoding => 'utf-16le')
File.open('/tmp/tmp_file', 'w') { |tmp_file| tmp_file.write(csv_text) }
puts 'made it here'
SmarterCSV.process('/tmp/tmp_file', {
:col_sep => "\t",
:force_simple_split => true,
:headers_in_file => false,
:user_provided_headers => headers
}).each do |row|
converted_row = {}
converted_row[:date_of_message] = row[:date_of_message][2..-2].to_date
converted_row[:timestamp] = row[:timestamp]
converted_row[:sender] = row[:sender][2..-2]
converted_row[:phone_number] = row[:phone_number][2..-2]
converted_row[:message] = row[:message][1..-2]
converted_row[:room] = file.gsub(path, '')
end
end
Update - 05/13/15
Ultimately, I decided to encode the file string as UTF-8 rather than diving deeper into the SmarterCSV code. The first problem in the SmarterCSV code is that it does not allow a user to specify binary mode when reading in a file, but after adjusting the source to handle that, a myriad of other encoding-related issues popped-up, many of which related to the handling of various parameters on files that were not UTF-8 encoded. It may have been the easy way out, but encoding everything as UTF-8 before feeding it into SmarterCSV solved my issue.

Add binmode to the File.read call.
File.read(file, :encoding => 'utf-16le', mode: "rb")
"b" Binary file mode
Suppresses EOL <-> CRLF conversion on Windows. And
sets external encoding to ASCII-8BIT unless explicitly
specified.
ref: http://ruby-doc.org/core-2.0.0/IO.html#method-c-read
Now pass the correct encoding to SmarterCSV
SmarterCSV.process('/tmp/tmp_file', {
:file_encoding => "utf-16le", ...
Update
It was found that smartercsv does not support binary mode. After the OP attempted to modify the code with no success it was decided the simple solution was to convert the input to UTF-8 which smartercsv supports.

Unfortunately, you're using a 'flat-file' style of storage and character encoding is going to be an issue on both ends (reading or writing).
I would suggest using something along the lines of str = str.force_encoding("UTF-8") and see if you can get that to work.

Related

ruby: How comes File.read in utf-8 fails to read a valid utf-8 character?

Context
Trying to parse with ruby 2.6.3+ a csv file utf-8 encoded
The file contains one character that throws a CSV::MalformedCSVError
After isolating, the character of interest seems to be the SINGLE LOW-9 QUOTATION MARK (U+201A). This one ‚.
That character seems to be supported by UTF-8 (3 bytes, in hex: e2809a or \xe2\x80\x9a) (ref1, ref2)
test.csv file content
"value"
"abc‚d"
Error when parsing with CSV class:
irb(main):001:0> require 'csv'
=> true
irb(main):002:0> CSV.read("test.csv", **{headers: true, skip_blanks: true, encoding: "utf-8"})
Traceback (most recent call last):
2: from C:/ruby/Ruby26-x64/lib/ruby/2.6.0/csv/parser.rb:297:in `parse'
1: from C:/ruby/Ruby26-x64/lib/ruby/2.6.0/csv/parser.rb:711:in `build_scanner'
CSV::MalformedCSVError (Invalid byte sequence in UTF-8 in line 2.)
although \u201a is a utf-8 supported character:
irb(main):001:0> str = "\u201a"
=> "‚"
irb(main):002:0> str.ord.to_s(16)
=> "201a"
irb(main):003:0> str.encoding.name
=> "UTF-8"
irb(main):004:0> str.unpack("H*")
=> ["e2809a"]
Treating encoding errors with scrub
Using String#scrub with a block does not seem to get the SINGLE LOW-9 QUOTATION MARK. See the code below (x82 refers to the original ‚):
irb(main):001:0> content = File.read('test.csv', encoding: 'utf-8')
=> "\"value\"\n\"abc\x82d\"\n"
irb(main):002:0> content.scrub! do |bytes|
irb(main):003:1* "<" + bytes.unpack('H*')[0] + ">"
irb(main):004:1> end
=> "\"value\"\n\"abc<82>d\"\n"
irb(main):005:0> require 'csv'
=> true
irb(main):006:0> CSV.parse(content, **{headers: true, skip_blanks: true, encoding: "utf-8"}).each do |row|
irb(main):007:1* pp row["value"]
irb(main):008:1> end
"abc<82>d"
=> #<CSV::Table mode:col_or_row row_count:2>
As shown above, the SINGLE LOW-9 QUOTATION MARK is replaced by <82>, the hexadecimal representation of the offending bytes. At this point, I am a bit lost.
Question
While it seems consistent that there is a CSV::MalformatedCSVError and that String#scrub fails to find the 3 bytes of the UTF-8 e2809a character (getting one byte instead: 0x82):
If the character \u201a is supported by UTF-8 (as e2809a), what can be the root cause of the error?
Opening the csv file in a text editor (Notepad++), the character is correctly displayed on the text area. When I copy and paste the character (‚) in this Unicode Lookup, it correctly identifies the character. So nothing seems to be wrong with it.
Looking at the code sample above (irb), nothing seems wrong with the usage of CSV.read and File.read. Could you confirm (explain) or discard if the error is related to the usage of those methods?
Perhaps there is nothing to fix, not to be expected, but I am not sure. It seems fairly difficult, if not impossible, to create a generic solution in ruby that correctly spots the offending character.

`scan': invalid byte sequence in UTF-8 (ArgumentError)

I'm trying to read a .txt file in ruby and split the text line-by-line.
Here is my code:
def file_read(filename)
File.open(filename, 'r').read
end
puts f = file_read('alice_in_wonderland.txt')
This works perfectly. But when I add the method line_cutter like this:
def file_read(filename)
File.open(filename, 'r').read
end
def line_cutter(file)
file.scan(/\w/)
end
puts f = line_cutter(file_read('alice_in_wonderland.txt'))
I get an error:
`scan': invalid byte sequence in UTF-8 (ArgumentError)
I found this online for untrusted website and tried to use it for my own code but it's not working. How can I remove this error?
Link to the file: File
The linked text file contains the following line:
Character set encoding: ISO-8859-1
If converting it isn't desired or possible then you have to tell Ruby that this file is ISO-8859-1 encoded. Otherwise the default external encoding is used (UTF-8 in your case). A possible way to do that is:
s = File.read('alice_in_wonderland.txt', encoding: 'ISO-8859-1')
s.encoding # => #<Encoding:ISO-8859-1>
Or even like this if you prefer your string UTF-8 encoded (see utf8everywhere.org):
s = File.read('alice_in_wonderland.txt', encoding: 'ISO-8859-1:UTF-8')
s.encoding # => #<Encoding:UTF-8>
It seems to work if you read the file directly from the page, maybe there's something funny about the local copy you have. Try this:
require 'net/http'
uri = 'http://www.ccs.neu.edu/home/vip/teach/Algorithms/7_hash_RBtree_simpleDS/hw_hash_RBtree/alice_in_wonderland.txt'
scanned = Net::HTTP.get_response(URI.parse(uri)).body.scan(/\w/)

Ruby converting string encoding from ISO-8859-1 to UTF-8 not working

I am trying to convert a string from ISO-8859-1 encoding to UTF-8 but I can't seem to get it work. Here is an example of what I have done in irb.
irb(main):050:0> string = 'Norrlandsvägen'
=> "Norrlandsvägen"
irb(main):051:0> string.force_encoding('iso-8859-1')
=> "Norrlandsv\xC3\xA4gen"
irb(main):052:0> string = string.encode('utf-8')
=> "Norrlandsvägen"
I am not sure why Norrlandsvägen in iso-8859-1 will be converted into Norrlandsvägen in utf-8.
I have tried encode, encode!, encode(destinationEncoding, originalEncoding), iconv, force_encoding, and all kinds of weird work-arounds I could think of but nothing seems to work. Can someone please help me/point me in the right direction?
Ruby newbie still pulling hair like crazy but feeling grateful for all the replies here... :)
Background of this question: I am writing a gem that will download an xml file from some websites (which will have iso-8859-1 encoding) and save it in a storage and I would like to convert it to utf-8 first. But words like Norrlandsvägen keep messing me up. Really any help would be greatly appreciated!
[UPDATE]: I realized running tests like this in the irb console might give me different behaviors so here is what I have in my actual code:
def convert_encoding(string, originalEncoding)
puts "#{string.encoding}" # ASCII-8BIT
string.encode(originalEncoding)
puts "#{string.encoding}" # still ASCII-8BIT
string.encode!('utf-8')
end
but the last line gives me the following error:
Encoding::UndefinedConversionError - "\xC3" from ASCII-8BIT to UTF-8
Thanks to #Amadan's answer below, I noticed that \xC3 actually shows up in irb if you run:
irb(main):001:0> string = 'ä'
=> "ä"
irb(main):002:0> string.force_encoding('iso-8859-1')
=> "\xC3\xA4"
I have also tried to assign a new variable to the result of string.encode(originalEncoding) but got an even weirder error:
newString = string.encode(originalEncoding)
puts "#{newString.encoding}" # can't even get to this line...
newString.encode!('utf-8')
and the error is Encoding::UndefinedConversionError - "\xC3" to UTF-8 in conversion from ASCII-8BIT to UTF-8 to ISO-8859-1
I am still quite lost in all of this encoding mess but I am really grateful for all the replies and help everyone has given me! Thanks a ton! :)
You assign a string, in UTF-8. It contains ä. UTF-8 represents ä with two bytes.
string = 'ä'
string.encoding
# => #<Encoding:UTF-8>
string.length
# 1
string.bytes
# [195, 164]
Then you force the bytes to be interpreted as if they were ISO-8859-1, without actually changing the underlying representation. This does not contain ä any more. It contains two characters, Ã and ¤.
string.force_encoding('iso-8859-1')
# => "\xC3\xA4"
string.length
# 2
string.bytes
# [195, 164]
Then you translate that into UTF-8. Since this is not reinterpretation but translation, you keep the two characters, but now encoded in UTF-8:
string = string.encode('utf-8')
# => "ä"
string.length
# 2
string.bytes
# [195, 131, 194, 164]
What you are missing is the fact that you originally don't have an ISO-8859-1 string, as you would from your Web-service - you have gibberish. Fortunately, this is all in your console tests; if you read the response of the website using the proper input encoding, it should all work okay.
For your console test, let's demonstrate that if you start with a proper ISO-8859-1 string, it all works:
string = 'Norrlandsvägen'.encode('iso-8859-1')
# => "Norrlandsv\xE4gen"
string = string.encode('utf-8')
# => "Norrlandsvägen"
EDIT For your specific problem, this should work:
require 'net/https'
uri = URI.parse("https://rusta.easycruit.com/intranet/careerbuilder_se/export/xml/full")
options = {
:use_ssl => uri.scheme == 'https',
:verify_mode => OpenSSL::SSL::VERIFY_NONE
}
response = Net::HTTP.start(uri.host, uri.port, options) do |https|
https.request(Net::HTTP::Get.new(uri.path))
end
body = response.body.force_encoding('ISO-8859-1').encode('UTF-8')
There's a difference between force_encoding and encode. The former sets the encoding for the string, whereas the latter actually transcodes the contents of the string to the new encoding. Consequently, the following code causes your problem:
string = "Norrlandsvägen"
string.force_encoding('iso-8859-1')
puts string.encode('utf-8') # Norrlandsvägen
Whereas the following code will actually correctly encode your contents:
string = "Norrlandsvägen".encode('iso-8859-1')
string.encode!('utf-8')
Here's an example running in irb:
irb(main):023:0> string = "Norrlandsvägen".encode('iso-8859-1')
=> "Norrlandsv\xE4gen"
irb(main):024:0> string.encoding
=> #<Encoding:ISO-8859-1>
irb(main):025:0> string.encode!('utf-8')
=> "Norrlandsvägen"
irb(main):026:0> string.encoding
=> #<Encoding:UTF-8>
The above answer was spot on. Specifically this point here:
There's a difference between force_encoding and encode. The former
sets the encoding for the string, whereas the latter actually
transcodes the contents of the string to the new encoding.
In my situation, I had a text file with iso-8859-1 encoding. By default, Ruby uses UTF-8 encoding, so if you were to try to read the file without specifying the encoding, then you would get an error:
results = File.read(file)
results.encoding
=> #<Encoding:UTF-8>
results.split("\r\n")
ArgumentError: invalid byte sequence in UTF-8
You get an invalid byte sequence error because the characters in different encodings are represented by different byte lengths. Consequently, you would need to specify the encoding to the File API. Think of it like force_encoding:
results = File.read(file, encoding: "iso-8859-1")
So everything is good right? No, not if you want to start parsing the iso-8859-1 string with UTF-8 character encodings:
results = File.read(file, encoding: "iso-8859-1")
results.each do |line|
puts line.split('¬')
end
Encoding::CompatibilityError: incompatible character encodings: ISO-8859-1 and UTF-8
Why this error? Because '¬' is represented as UTF-8. You are using a UTF-8 character sequence against an ISO-8859-1 string. They are incompatible encodings. Consequently, after you read the File as a ISO-8859-1, then you can ask Ruby to encode that ISO-8859-1 into a UTF-8. And now you will be working with UTF-8 strings and thus no problems:
results = File.read(file, encoding: "iso-8859-1").encode('UTF-8')
results.encoding
results = results.split("\r\n")
results.each do |line|
puts line.split('¬')
end
Ultimately, with some Ruby APIs, you do not need to use force_encoding('ISO-8859-1'). Instead, you just specify the expected encoding to the API. However, you must convert it back to UTF-8 if you plan to parse it with UTF-8 strings.

How to avoid getting UndefinedConversionError during decoding a file?

I have somefile which I want to encode using base64
File.open('data/somefile.edf').read.encoding
=> #<Encoding:UTF-8>
base64_string = Base64.encode64(open("data/somefile.edf").to_a.join)
And then I want to decode that file
file = open('new_edf.edf', 'w') do |file|
file << Base64.decode64(base64_string)
end
But I get an error:
Encoding::UndefinedConversionError: "\xE1" from ASCII-8BIT to UTF-8
from (pry):22:in `write'
I believe the problem is that by default the file is opened for writing in text mode. To fix this, open the file using binary mode:
File.open('new_edf.edf', 'wb') { ... }
You can also check out this other question: Ruby 1.9 Base64 encoding write to file error

Ruby CSV UTF8 encoding error while reading

This is what I was doing:
csv = CSV.open(file_name, "r")
I used this for testing:
line = csv.shift
while not line.nil?
puts line
line = csv.shift
end
And I ran into this:
ArgumentError: invalid byte sequence in UTF-8
I read the answer here and this is what I tried
csv = CSV.open(file_name, "r", encoding: "windows-1251:utf-8")
I ran into the following error:
Encoding::UndefinedConversionError: "\x98" to UTF-8 in conversion from Windows-1251 to UTF-8
Then I came across a Ruby gem - charlock_holmes. I figured I'd try using it to find the source encoding.
CharlockHolmes::EncodingDetector.detect(File.read(file_name))
=> {:type=>:text, :encoding=>"windows-1252", :confidence=>37, :language=>"fr"}
So I did this:
csv = CSV.open(file_name, "r", encoding: "windows-1252:utf-8")
And still got this:
Encoding::UndefinedConversionError: "\x8F" to UTF-8 in conversion from Windows-1252 to UTF-8
It looks like you have problem with detecting the valid encoding of your file. CharlockHolmes provide you with useful tip of :confidence=>37 which simply means the detected encoding may not be the right one.
Basing on error messages and test_transcode.rb from https://github.com/MacRuby/MacRuby/blob/master/test-mri/test/ruby/test_transcode.rb I found the encoding that passes through both of your error messages. With help of String#encode it's easy to test:
"\x8F\x98".encode("UTF-8","cp1256") # => "ڈک"
Your issue looks like strictly related to the file and not to ruby.
In case we are not sure which encoding to use and can agree to loose some character we can use :invalid and :undef params for String#encode, in this case:
"\x8F\x98".encode("UTF-8", "CP1250",:invalid => :replace, :undef => :replace, :replace => "?") # => "Ź?"
other way is to use Iconv *//IGNORE option for target encoding:
Iconv.iconv("UTF-8//IGNORE","CP1250", "\x8F\x98")
As a source encoding suggestion of CharlockHolmes should be pretty good.
PS. String.encode was introduced in ruby 1.9. With ruby 1.8 you can use Iconv

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