Forum: Ruby file size of each item in file list

I am trying to take the contents of a file which contains the results of
a file size search and print those out with ruby.  To obtain the file
size of each line in that file.

#!/usr/bin/ruby

f = File.open("/tmp/lg_files")
contentsArray=[]  # start with an empty array
   f.each_line {|line|
   a = contentsArray.push line
   #b = File.size(a)
   puts a
}


This results in each line in the file /tmp/lg_files printing.

Sloan Ruby wrote in post #1096778:
> I am trying to take the contents of a file which contains the results of
> a file size search and print those out with ruby.  To obtain the file
> size of each line in that file.
>
> #!/usr/bin/ruby
>
> f = File.open("/tmp/lg_files")
do this in a block so it closes the file afterwards:
File.read("/tmp/lg_files") do |f|
> contentsArray=[]  # start with an empty array
>    f.each_line {|line|
>    a = contentsArray.push line
where did "a" come from? You already have a variable storing this 
information: contentsArray.
>    #b = File.size(a)
try "File.size contentsArray.last" instead
>    puts a
> }
>
>
> This results in each line in the file /tmp/lg_files printing.

This is what I have now.   I am not able to print out each line of the 
file /tmp/lg_files.   There is no output.  What am i missing?

#!/usr/bin/ruby

system('find /var -type f -size +20000 >> /tmp/lg_files')
#do this in a block so it closes the file afterwards:
File.read("/tmp/lg_files") do |f|
contentsArray=[]  # start with an empty array
   f.each_line {|line|
   #a = contentsArray.push line
        b = File.size contentsArray.last
   puts b
}
end
#system('> /tmp/lg_files')

On Wed, Feb 13, 2013 at 3:08 PM, Sloan Ruby <lists@ruby-forum.com> 
wrote:
> This is what I have now.   I am not able to print out each line of the
> file /tmp/lg_files.   There is no output.  What am i missing?

> File.read("/tmp/lg_files") do |f|
> contentsArray=[]  # start with an empty array
>    f.each_line {|line|
>    #a = contentsArray.push line
>         b = File.size contentsArray.last
>    puts b
> }
> end

You've commented out the contentsArray.push line which insures
that it's always empty, for one thing :-)

Regardless, you don't need that at all. Something like this:

File.open("/tmp/lg_files","r").readlines.each do |line|
    line.chomp!;
    puts "#{line} #{File.size(line)}"
end

should do what you want with fewer moving parts.

HTH,

On Wed, Feb 13, 2013 at 4:30 PM, Sloan Ruby <lists@ruby-forum.com> 
wrote:
>    #b = File.size(a)
>    puts a
> }
>
>
> This results in each line in the file /tmp/lg_files printing.

Is this just an partial step to doing something else? Because to do
what you originally posted, all that's required is something like
this:

IO.readlines("/tmp/lg_files").each{|l| l.chomp!; puts "#{l} 
#{File.size(l)}" }

On Thu, Feb 14, 2013 at 12:49 AM, Hassan Schroeder
<hassan.schroeder@gmail.com> wrote:
>> }
>> end
>
> You've commented out the contentsArray.push line which insures
> that it's always empty, for one thing :-)

Even worse: File.read will ignore the block.  It's simply never
executed.  Otherwise one would see an error.

> Regardless, you don't need that at all. Something like this:
>
> File.open("/tmp/lg_files","r").readlines.each do |line|

Better use

File.foreach "/tmp/lg_files" do |line|

That avoids reading the whole file into memory.

>     line.chomp!;
>     puts "#{line} #{File.size(line)}"
> end

> should do what you want with fewer moving parts.

I think that approach is still more complicated than necessary.  First
of all, the temporary file can be omitted because with IO.popen and
similar methods one can directly read the output of the find command.

It gets even better: one can also do the file system search in Ruby.
There is no point in doing that externally.  There are actually two
ways:
Find.find()
Pathname#find()

Example:

require 'pathname'

Pathname('/var').find do |file|
  printf "%10d %s\n", file.size, file if file.file? && file.size >= 
20_000
end

Kind regards

robert

Robert Klemme wrote in post #1096937:
> Even worse: File.read will ignore the block.  It's simply never
> executed.  Otherwise one would see an error.

I didn't notice this, it should have been
contentsArray = File.read('/tmp/lg_files').split $/

On Feb 14, 2013, at 12:32 PM, Joel Pearson wrote:

> Robert Klemme wrote in post #1096937:
>> Even worse: File.read will ignore the block.  It's simply never
>> executed.  Otherwise one would see an error.
>
> I didn't notice this, it should have been
> contentsArray = File.read('/tmp/lg_files').split $/

If you want the entire set of lines, just use

contentsArray = File.readlines('/tmp/lg_files')

http://apidock.com/ruby/v1_9_3_125/IO/readlines/class

Hah, Ruby's always one step ahead of me :p