Edit each line in a file in Ruby

Question

I\'m trying to find a simple way of editing each line in a file, and I\'m having some trouble understanding how to use the File class to do so.

The file

Answer 1

The problem with the accepted answer is that it modifies file permissions and ownership (pay attention to that).

Another approach is to use inplace editing inside Ruby (not from the command line):

#!/usr/bin/ruby

def inplace_edit(file, bak, &block)
    old_stdout = $stdout
    argf = ARGF.clone

    argf.argv.replace [file]
    argf.inplace_mode = bak
    argf.each_line do |line|
        yield line
    end
    argf.close

    $stdout = old_stdout
end

inplace_edit 'test.txt', '.bak' do |line|
    line = line.gsub(/search1/,"replace1")
    line = line.gsub(/search2/,"replace2")
    print line unless line.match(/something/)
end

If you don't want to create a backup then change '.bak' to ''.