Newb: Search & Replace

ruby-talk
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

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')

···

On Sat, 31 Dec 2005, Art Gillespie wrote:

#!/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")

--
Wybo

3

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

···

On 12/31/05, Art Gillespie <agillesp@gmail.com> 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...

4

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

···

Wybo Dekker <wybo@servalys.nl> wrote:

On Sat, 31 Dec 2005, Art Gillespie wrote:

#!/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")

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')

5

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

···

On 12/31/05, Ryan Leavengood <leavengood@gmail.com> wrote:

On 12/31/05, Art Gillespie <agillesp@gmail.com> 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

Uhm... ruby is not needed:

sed -ie 's/x/y/g' iDrum_prefix.h

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

···

On Sat, 31 Dec 2005, Robert Klemme wrote:

Wybo Dekker <wybo@servalys.nl> wrote:
> On Sat, 31 Dec 2005, Art Gillespie wrote:
>
> > #!/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")
>
> 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')

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

--
Wybo