Newb: Search & Replace


#1

Hi all,

I’m implementing build automation in Ruby as a ‘learn Ruby’ exercise.
I wanted to post the following code and solicit feedback on any idioms
I might have missed with regards to text processing with Ruby. The
code works–I’m just wondering if it should be shorter, or smarter,
or…

Thanks,

Art


#!/usr/bin/env ruby

VERSION_HEX=ARGV[0]

File.open(“iDrum_prefix.h.tmp”, “w”) do |ofile|
File.open(“iDrum_prefix.h”) do |file|
file.each do |line|
if line =~ /^#define kIDComponentVersion\t*(.*)/
ofile.puts line.sub($1, “#{VERSION_HEX}”)
else
ofile.puts line
end
end
end
end

File.rename(“iDrum_prefix.h.tmp”, “iDrum_prefix.h”)


#2

On Sat, 31 Dec 2005, Art G. wrote:

    ofile.puts line
  end
end

end
end

File.rename(“iDrum_prefix.h.tmp”, “iDrum_prefix.h”)

with rio, you can edit a file inplace;
this changes all x into y in file z:

#!/usr/bin/ruby
require ‘rubygems’
require ‘rio’
rio(‘z’) < rio(‘z’).read.gsub(/x/,‘y’)


#3

Wybo D. removed_email_address@domain.invalid wrote:

    ofile.puts line.sub($1, "#{VERSION_HEX}")

this changes all x into y in file z:

#!/usr/bin/ruby
require ‘rubygems’
require ‘rio’
rio(‘z’) < rio(‘z’).read.gsub(/x/,‘y’)

Um, rio is not needed:

Robert@Babelfish2 /c/TEMP
$ echo ‘x’ > iDrum_prefix.h

Robert@Babelfish2 /c/TEMP
$ cat iDrum_prefix.h
x

Robert@Babelfish2 /c/TEMP
$ ruby -i.tmp -pe “gsub /x/, ‘y’” iDrum_prefix.h

Robert@Babelfish2 /c/TEMP
$ cat iDrum_prefix.h
y

:-))

robert

#4

On Sat, 31 Dec 2005, Robert K. wrote:

if line =~ /^#define kIDComponentVersion\t*(.*)/
with rio, you can edit a file inplace;
$ echo ‘x’ > iDrum_prefix.h
y

:-))

robert

Uhm… ruby is not needed:

sed -ie ‘s/x/y/g’ iDrum_prefix.h

But I suppose that Art G. wanted to arrange things from a Ruby
script, where he does other things as well… Happy New Year!


#5

On 12/31/05, Art G. removed_email_address@domain.invalid wrote:

Hi all,

I’m implementing build automation in Ruby as a ‘learn Ruby’ exercise.
I wanted to post the following code and solicit feedback on any idioms
I might have missed with regards to text processing with Ruby. The
code works–I’m just wondering if it should be shorter, or smarter,
or…

That is nice and idiomatic from my perspective. In fact I’ve written
code much like that to do what you are doing. While there might be
various tricks and hacks to make it shorter, they probably aren’t
needed.

Ryan


#6

Thanks for the replies, everyone. I wound up with

def do_substitution( filename )
File.open("#{filename}.tmp", “w”) do |ofile|
File.open("#{filename}") do |file|
file.each do |line|
yield ofile, line
end
end
end
File.rename("#{filename}.tmp", “#{filename}”)
end

Which is probably overkill for my needs, but got me learning about
blocks and is flexible. And fun!

Thanks again.

Art