I'm having troubles trying to download word documents from a dropbox using an APP controlled by a ruby program. (I would like to have the ability to download any file from a dropbox).
The code they provide is great for "downloading" a .txt file, but if you try using the same code to download a .docx file, the "downloaded" file won't open in word due to "corruption."
The code I'm using:
contents = #client.get_file(path + filename)
open(filename, 'w') {|f| f.puts contents }
For variable examples, path could be '/', and filename could be 'aFile.docx'. This works, but the file, aFile.docx, that is created can not be opened. I am aware that this is simply grabbing the contents of the file and then creating a new file and inserting the contents.
Try this:
open(filename, 'wb') { |f| f.write contents }
Two changes from your code:
I used the file mode wb to specify that I'm going to write binary data. I don't think this makes a difference on Linux and OS X, but it matters on Windows.
I used write instead of puts. I believe puts expects a string, while you're trying to write arbitrary binary data. I assume this is the source of the "corruption."
Related
I have a zip file in Ruby at a particular location on the file system. There is only 1 file in that zip file. I want to read the content of that file. How can I do it (without knowing the name of the file up-front)? I've tried looking at various libraries/ways but the APIs were either outdated, or the libraries weren't maintained for years.
You can use RubyZip:
require 'zip'
a = Zip::File.open(path_to_zip_file) { |z| z.first.get_input_stream.read }
I am trying to read a list of baby names from the year 1880 in CSV format. My program, when run in the terminal on OS X returns an error indicating yob1880.txt doesnt exist.
No such file or directory # rb_sysopen - /names/yob1880.txt (Errno::ENOENT)
from names.rb:2:in `<main>'
The location of both the script and the text file is /Users/*****/names.
lines = []
File.expand_path('../yob1880.txt', __FILE__)
IO.foreach('../yob1880.txt') do |line|
lines << line
if lines.size >= 1000
lines = FasterCSV.parse(lines.join) rescue next
store lines
lines = []
end
end
store lines
If you're running the script from the /Users/*****/names directory, and the files also exist there, you should simply remove the "../" from your pathnames to prevent looking in /Users/***** for the files.
Use this approach to referencing your files, instead:
File.expand_path('yob1880.txt', __FILE__)
IO.foreach('yob1880.txt') do |line|
Note that the File.expand_path is doing nothing at the moment, as the return value is not captured or used for any purpose; it simply consumes resources when it executes. Depending on your actual intent, it could realistically be removed.
Going deeper on this topic, it may be better for the script to be explicit about which directory in which it locates files. Consider these approaches:
Change to the directory in which the script exists, prior to opening files
Dir.chdir(File.dirname(File.expand_path(__FILE__)))
IO.foreach('yob1880.txt') do |line|
This explicitly requires that the script and the data be stored relative to one another; in this case, they would be stored in the same directory.
Provide a specific path to the files
# do not use Dir.chdir or File.expand_path
IO.foreach('/Users/****/yob1880.txt') do |line|
This can work if the script is used in a small, contained environment, such as your own machine, but will be brittle if it data is moved to another directory or to another machine. Generally, this approach is not useful, except for short-lived scripts for personal use.
Never put a script using this approach into production use.
Work only with files in the current directory
# do not use Dir.chdir or File.expand_path
IO.foreach('yob1880.txt') do |line|
This will work if you run the script from the directory in which the data exists, but will fail if run from another directory. This approach typically works better when the script detects the contents of the directory, rather than requiring certain files to already exist there.
Many Linux/Unix utilities, such as cat and grep use this approach, if the command-line options do not override such behavior.
Accept a command-line option to find data files
require 'optparse'
base_directory = "."
OptionParser.new do |opts|
opts.banner = "Usage: example.rb [options]"
opts.on('-d', '--dir NAME', 'Directory name') {|v| base_directory = Dir.chdir(File.dirname(File.expand_path(v))) }
end
IO.foreach(File.join(base_directory, 'yob1880.txt')) do |line|
# do lines
end
This will give your script a -d or --dir option in which to specify the directory in which to find files.
Use a configuration file to find data files
This code would allow you to use a YAML configuration file to define where the files are located:
require 'yaml'
config_filename = File.expand_path("~/yob/config.yml")
config = {}
name = nil
config = YAML.load_file(config_filename)
base_directory = config["base"]
IO.foreach(File.join(base_directory, 'yob1880.txt')) do |line|
# do lines
end
This doesn't include any error handling related to finding and loading the config file, but it gets the point across. For additional information on using a YAML config file with error handling, see my answer on Asking user for information, and never having to ask again.
Final thoughts
You have the tools to establish ways to locate your data files. You can even mix-and-match solutions for a more sophisticated solution. For instance, you could default to the current directory (or the script directory) when no config file exists, and allow the command-line option to manually override the directory, when necessary.
Here's a technique I always use when I want to normalize the current working directory for my scripts. This is a good idea because in most cases you code your script and place the supporting files in the same folder, or in a sub-folder of the main script.
This resets the current working directory to the same folder as where the script is situated in. After that it's much easier to figure out the paths to everything:
# Reset working directory to same folder as current script file
Dir.chdir(File.dirname(File.expand_path(__FILE__)))
After that you can open your data file with just:
IO.foreach('yob1880.txt')
I have a tar.gz file saved on disk and I want to leave it packed there, but I need to open one file within the archive, read from it and save some information somewhere.
File structure:
base_folder
file_i_need.txt
other_folder
other_file
code (it is not much - I tried 10mio different ways and this is what is left)
def self.open_file(file)
uncompressed_file = Gem::Package::TarReader.new(Zlib::GzipReader.open(file))
uncompressed_file.rewind
end
When I run it in a console I get
<Gem::Package::TarReader:0x007fbaac178090>
and I can run commands on the entries. I just haven't figured out how to open an entry and read from it without saving it unpacked to disk. I mainly need the string from the text file.
Any help appreciated. I might just be missing something...
TarReader is Enumerable, returning Entry.
That said, to retrieve the text content from the file by it’s name one might
uncompressed = Gem::Package::TarReader.new(Zlib::GzipReader.open(file))
text = uncompressed.detect do |f|
f.fullname == 'base_folder/file_i_need.txt'
end.read
#⇒ Hello, I’m content of the text file, located inside gzipped tar
Hope it helps.
I am using twitter ruby gem to fetch twitter search result. The example code from Github extracts the information from search result.I am wondering how to save the search result, which is JSON i think, to a separate JSON file.
Here is part of the example code:
results = #search.perform("$aaa", 1000)
aFile = File.new("data.txt", "w")
results.map do |status|
myStr="#{status.from_user}: #{status.text} #{status.created_at}"
aFile.write(myStr)
aFile.write("\n")
end
Is there any way to save all the search result to a separate JSON file instead of writing strings to a file?
Thanks in advance.
If you want to save to a file all you need to do is open the file, write it it, then close it:
File.open("myFileName.txt", "a") do |mFile|
mFile.syswrite("Your content here")
mFile.close
end
When you use open you will create the file if it doesn't exist.
One thing to be aware of is that there are different ways to open file, of which will determine where the program writes to. The "a" indicates that it will append everything you write to the file, to the end of the current content.
Here is some of the options:
r Read-only mode. The file pointer is placed at the beginning of the file. This is the default mode.
r+ Read-write mode. The file pointer will be at the beginning of the file.
w Write-only mode. Overwrites the file if the file exists. If the file does not exist, creates a new file for writing.
w+ Read-write mode. Overwrites the existing file if the file exists. If the file does not exist, creates a new file for reading and writing.
a Write-only mode. The file pointer is at the end of the file if the file exists. That is, the file is in the append mode. If the file does not exist, it creates a new file for writing.
a+ Read and write mode. The file pointer is at the end of the file if the file exists. The file opens in the append mode. If the file does not exist, it creates a new file for reading and writing.
So in your case, you would want to pull out the data you want to save, then write it to a file as I have shown. You can also specify file paths by doing:
File.open("/the/path/to/yourfile/myFileName.txt", "a") do |mFile|
mFile.syswrite("Your content here")
mFile.close
end
Another thing to be aware of is that open does not create directories, so you will either need to create directories yourself, or you can do it with your program. Here is a link that is helpful for file input/output:
http://www.tutorialspoint.com/ruby/ruby_input_output.htm
Hi I'm trying to read a pdf in Ruby, first of all I want to convert it into a txt. path is the path to the PDF, The point is that I get a .txt file empty, and as someone told me is a pdftotext problem, but I don't know how to fix it.
spec = path.sub(/\.pdf$/, '')
`pdftotext #{spec}.pdf`
file = File.new("#{spec}.txt", "w+")
text = []
file.readlines.each do |l|
if l.length > 0
text << l
Rails.logger.info l
end
end
file.close
What's wrong with my code? Thanks!
It's not possible to extract text from every PDF. Some PDF files use a font encoding that makes it impossible to extract text with simple tools such as pdftotext (and some PDF files are even completely immune to direct text extraction with any tool known to me -- in these cases you'll have to apply OCR first to have a chance to extract text...).
So if you test your code with the same "weird" PDF file all the time, it may well happen that you're getting frustrated over your code while in reality the fault lies with the PDF.
First make sure that the commandline usage of pdftotxt works well with a given PDF, then test (and develop further) your code with that PDF.
The problem is you are opening the file in write ("w") mode, whuch truncates the file. You can see a table of file modes and what they mean at http://ruby-doc.org/core-1.9.3/IO.html.
Try something like this, it uses a pdftotext option to send the text to stdout to avoid creating a temporary file and uses blocks for more idiomatic ruby.
text = `pdftotext #{path} -`
text.split.select { |line|
line.length > 0
}.each { |line|
Rails.logger.info(line)
}
You would need to open the txt file with write permission.
file = File.new("#{spec}.txt", "w")
You could consult How to create a file in Ruby
Update: your code is not complete and looks buggy.
Cant say what is path
Looks like you are trying to read the text file to which you intend to write file.readlines.each
spell check length you have it l.lenght
You may want to paste the actual code.
Check this gist https://gist.github.com/4160587
As mentioned, your code is not working because you are reading and writing to the same file.
Example
Ruby code file_write.rb to do the file write operation
pdf_file = File.open("in.txt")
output_file = File.open("out.txt", "w") # file to which you want to write
#iterate over input file and write the content to output file
pdf_file.readlines.each do |l|
output_file.puts(l)
end
output_file.close
pdf_file.close
Sample txt file in.txt
Some text in file
Another line of text
1. Line 1
2. Not really line 2
Once your run file_write.rb you should see new file called out.txt with same content as in.txt You could change the content of input file if you want. In your case you would use pdf reader to get the content and write it to the text file. Basically first line of the code will change.