read data line by line

[Krishna Vutukuru]

could anybody please give me an example of how to read data from a text
file line by line so that manipulations can be made on each and
everyline and copy those to other file?

 

[Harry]

could anybody please give me an example of how to read data from a text
file line by line so that manipulations can be made on each and
everyline and copy those to other file?

http://www.ruby-forum.com/topic/103371#new

Harry

 

[James Edward Gray II]

could anybody please give me an example of how to read data from a
text
file line by line so that manipulations can be made on each and
everyline and copy those to other file?

File.open("output.txt", "w") do |output|
File.foreach("input.txt") do |line|
# change line here...
output << line
end
end

Hope that helps.

James Edward Gray II

 

[Vassilis Rizopoulos]

File.open("output.txt", "w") do |output| File.foreach("input.txt") do
|line| # change line here... output << line end end

Hope that helps.

James Edward Gray II

As well as something like this

lines=File.readlines("filename")
lines.collect!{|l| do something with l and give it back}
File.open("output","w"){|f| f<<lines.join("\n")}

Pedantic, I know
V.-

 

[James Edward Gray II]

As well as something like this

lines=File.readlines("filename")
lines.collect!{|l| do something with l and give it back}
File.open("output","w"){|f| f<<lines.join("\n")}

Pedantic, I know

The problem with your solution is that it slurps all the data into
memory at once. For large data sets, this may not be an option.

My solution only reads one line at a time and thus is a lot more
memory friendly.

James Edward Gray II