From: David Jacobs <david@...>
Date: 2012-09-01T13:42:22+09:00
Subject: Re: Parsing unix filenames from STDIN

FYI I ended up using the following (turns out I didn't need bash expansion because I'll always get that from the previous tool in the pipeline):  

if $stdin.tty?
  # … do something
else
  files = $stdin.each_line.reduce([]) do |list, line|
    list.concat(Shellwords.split(line))
  end


  # … do something with files
end


On Monday, August 27, 2012 at 2:51 AM, Robert Klemme wrote:

> On Sat, Aug 25, 2012 at 11:51 AM, Sean O'Halpin <sean.ohalpin@gmail.com (mailto:sean.ohalpin@gmail.com)> wrote:
> > On Sat, Aug 25, 2012 at 12:57 AM, David Jacobs <david@wit.io (mailto:david@wit.io)> wrote:
> > > How can I parse filenames read from STDIN via the standard Unix parsing rules (without duplicating said rules)? All of the following would be parsed as coherent file names:
> > >  
> > > file.txt
> > > my\ file.txt
> > > "my file.txt"
> > >  
> > > A nice addition would be that *.txt would use Bash expansion to find the appropriate files.
> >  
> > Use Shellwords to handle shell escaped strings and Dir[] to expand wildcards:
> >  
> > require 'shellwords'
> > while line = STDIN.gets
> > filename = Shellwords.shellwords(line).join('')
> > p filename
> > # expand wildcards
> > p Dir[filename]
> > end
>  
>  
>  
> Two additional cents:
>  
> 1. I'd rather use $stdin instead of STDIN, see here for reasoning:
> http://stackoverflow.com/questions/4279604/what-is-the-difference-between-stdin-and-stdin-in-ruby
>  
> 2. One can as well use the usual iteration for reading lines from files.
>  
> =>
>  
> require 'shellwords'
>  
> $stdin.each_line do |line|
> filename = Shellwords.shellwords(line).join('')
> p filename
> # expand wildcards
> p Dir[filename]
> end
>  
> Advantage is also that the scope of "line" is limited to the block
> reducing potential for errors.
>  
> Btw, Sean, are you sure David will join all the shellwords? I am
> asking since he said there were commands as well and he basically
> wants to parse in the same way the shell does. So:
>  
> irb(main):006:0> ['my\\ file.txt', '"my file.txt"', 'ls foo\\
> bar.txt'].each {|s| printf "%p -> %p\n", s, Shellwords.shellwords(s)}
> "my\\ file.txt" -> ["my file.txt"]
> "\"my file.txt\"" -> ["my file.txt"]
> "ls foo\\ bar.txt" -> ["ls", "foo bar.txt"]
> => ["my\\ file.txt", "\"my file.txt\"", "ls foo\\ bar.txt"]
>  
>  
> Kind regards
>  
> robert
>  
> --  
> remember.guy do |as, often| as.you_can - without end
> http://blog.rubybestpractices.com/