From: dblack@...
Date: 2002-10-11T02:17:34+09:00
Subject: Re: undefined method for nil..

Hello --

On Fri, 11 Oct 2002, Enric Lafont wrote:

> #### This is my program, a simple parser for the djbdns flat database ###
> argfile=ARGV[0]
> inFile= (argfile == nil or argfile.upcase == 'STDIN' ) ? STDIN :
> File.new(argfile,'r')
>
> firstChar=''
> inFile.each_line { | line |
>   line.chomp!
>   firstChar=line[0].chr
>   arr=firstChar.to_a + line[1,line.size].split(':')
> # ... More code here, but the interpreter accepts it
> }
>
> The interpreter says that
> dns_process.rb:7: undefined method `chr' for nil (NameError)
>         from dns_process.rb:5:in `each_line'
>         from dns_process.rb:5
>
> It seems that ruby understands that line[0] is a "nil" so he can not
> find the "chr" method, when in fact "line" is a string and "line[0]" is
> an integer, so "chr" is a right method for an integer, but ruby seems
> not to understand this

Well, I think we can pretty confidently say that line[0] is nil :-)

If you have a blank line, and chomp! it, you then have an empty string.
And then, the [0] element will be nil.

So, I suspect there's one or more empty lines in the file.

Try this:

   # ...
   line.chomp!
   next unless line[0]
   # ...


David

-- 
David Alan Black                      | Register for RubyConf 2002!
home: dblack@candle.superlink.net     | November 1-3
work: blackdav@shu.edu                | Seattle, WA, USA
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