From: daz <dooby@...10.karoo.co.uk>
Date: 2003-06-14T22:42:19+09:00
Subject: Re: problems with Net::FTP


"John Jenniskens" <John.Jenniskens@xs4all.nl> wrote:

> Hello,
>
> I want to make a program that transfers a lot of files to another computer
> by means of FTP. I want to check if the target directory exist. I want to do
> a chdir, and if I retrieve a status indicating the directory doesn't exist,
> I want to issue a mkdir command.
>
> When I issue a chdir (or even a list) on a non existing file, Ruby stops:
> V:/RUBY/lib/ruby/1.6/net/ftp.rb:129:in `getresp': 550 /abc: The system
> cannot find the file specified.  (Net::FTPPermError)
>         from V:/RUBY/lib/ruby/1.6/net/ftp.rb:137:in `voidresp'
>         from V:/RUBY/lib/ruby/1.6/net/ftp.rb:298:in `retrlines'
>         from V:/RUBY/lib/ruby/1.6/net/ftp.rb:285:in `mon_synchronize'
>         from V:/RUBY/lib/ruby/1.6/net/ftp.rb:285:in `retrlines'
>         from V:/RUBY/lib/ruby/1.6/net/ftp.rb:447:in `list'
>
> How can I avoid this stopping, and getting the status in my program?
>
> I'm using Ruby 1.6.6 on Windows2000.
>
> Kind regards,
>
> John Jenniskens
>
>

Like ruby itself, many libraries provide classes of exceptions
which can be handled by (a) rescue clause(s); usually within a
begin / end block.  Below, only permanent errors are trapped and
the FTP#lastresp method is called to see what the trouble is.
Your result above shows that a '550' response was received from
the server for 'file/dir not found' so, if it's returned, a new
directory is created and the chdir is retried.

I just ran this on my 20MB of free virtual web-space that's doing
nothing but being virtual at the moment with quite spectacular
success.  The Ruby crew (or crubies as they're never called :) who
write these libraries are absolute stars because, without them,
it wouldn't just take longer for us to write a script ..- more
than likely, it wouldn't get started / finished at all.

Thanks in this particular case (Net::FTP) go to Shugo Maeda.


A few changes at the top for folks to make to personalise this.


#<--start-->
### Personal FTP Log-In details  -  ((CHANGE))
MY_WEBSPACE_FTP = 'homepag#s.##########'
ACCOUNT = nil  # I'm a single user account (not used)
USER = 'you'
PASSWORD = 'opensesa-you'
#^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^#
#     ---   S E C U R I T Y   ---     #
#^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^#

Dir.chdir('C:\TEMP') # local temp-file directory ???
TEMP_FILENAME = 'test6.txt'
FTP_DIR_NAME  = 'rbjun14'
# File to browse will be:
#  (Your-www-site)/rbjun14/test6.txt

# If the correct details are entered above,
# the rest of the script should work for most people.

### Create a local text file to upload via FTP
line_t = format("*****  %s  *****", Time.now)
line_b = '*' << '=' * (line_t.length-2) << '*'

File.open(TEMP_FILENAME, 'w') do |tmp|
  tmp.puts(line_b, line_t, line_b)
end

require 'net/ftp'

ftp = Net::FTP.open(MY_WEBSPACE_FTP, USER, PASSWORD, ACCOUNT)

begin
  retries = 1
  begin
    ftp.chdir(FTP_DIR_NAME)
  rescue Net::FTPPermError => err
    puts "Last response = #{ftp.lastresp}"
    puts err
    if ftp.lastresp == '550'  # No such directory
      retries -= 1
      unless retries < 0
        ### Create test directory ###
        puts "Creating #{FTP_DIR_NAME} directory"
        ftp.mkdir(FTP_DIR_NAME)
        ###
        retry
      end
    end
    raise 'Directory unavailable'
  end
  puts "Uploading file #{TEMP_FILENAME}"
  ftp.puttextfile(TEMP_FILENAME, TEMP_FILENAME)
  file_list = ftp.nlst('*')
  puts '-' * 80
  puts file_list

##  ftp.delete(TEMP_FILENAME)
##  ftp.chdir('..')  # parent dir
##  ftp.rmdir(FTP_DIR_NAME)
ensure
  ftp.close ## Close Connection
  File.delete(TEMP_FILENAME) # local (temp) text file
end
#<--end-->


#-> Last response = 550
#-> 550 No such directory.
#-> Creating rbjun14 directory
#-> Uploading file test6.txt
#-> --------------------------------------------------------------------------------
#-> test6.txt


daz