getting the last word in each line

[Joe Van Dyk]

Is there a prettier way to read a file and return the last word in each line?

Here's my go:

File.read(some_file).to_a.map { |l| line.split.last }

What if I wanted to search the lines (based on a regex) and return the
last word in each line that satisfied the search criteria?

Joe

 

[Vincent Fourmond]

Hello !

File.read(some_file).to_a.map { |l| line.split.last }

What if I wanted to search the lines (based on a regex) and return the
last word in each line that satisfied the search criteria?

What about

File.read(some_file).to_a.map { |l| line.split.select {|v| v =~
/regex/}.last }

Vince

 

[Ben Bleything]

Is there a prettier way to read a file and return the last word in each
line?

Well, there's #readlines...

File.readlines('somefile').map {|f| f.split.last}

...which is a little nicer.

What if I wanted to search the lines (based on a regex) and return the
last word in each line that satisfied the search criteria?

File.readlines('somefile').map do |f|
next unless f =~ /regex/
f.split.last
end

But you'll have nils everywhere that a line was next'ed over...

File.readlines('somefile').reject{|f| f !~ /regex/}.map {|f| f.split.last}

Someone else might have an elegant solution, but these will work

Ben

 

[Dominique Plante]

in irb:

r = /\w+$/ => /\w+$/
s = "bad boy" => "bad boy"
md = s.match(r)

md[0]

=> "boy"

 

[Joel VanderWerf]

File.read(some_file).to_a.map { |l| line.split.last }

line[/(\w+)\s*$/, 1]

might be faster than line.split.last. Worth trying anway.

 

[nobu]

Hi,

At Wed, 13 Sep 2006 06:57:47 +0900,
Joe Van Dyk wrote in [ruby-talk:214152]:

File.read(some_file).to_a.map { |l| line.split.last }

$ ruby -e 'p open(ARGV[0]){|f|f.grep(/(\w+)\s*$/){$1}}' version.h
["190", "20060912", "1", "9", "0", "2006", "9", "12"]

 

[Logan Capaldo]

What about

File.read(some_file).to_a.map { |l| line.split.select {|v| v =~
/regex/}.last }

That call to_a is unecessary. File.read(some_file).map { ... } will work
just as well.