Asp Forum - search a file and replace text

phil swenson

4/3/2007 3:48:00 PM

I need to search a specific xml file in a directory, look for:

<port system-property="tangosol.coherence.clusterport">30890</port>

and if the port 30890 is still there replace it with a different
integer.

I know of several ways to do this (like open the file, iterate the
lines until I find the integer, do a gsub! on on the integer). But it
seems like there might be a better way to do it. Is there a search
and replace API I don't know about?

Any thoughts?

7 Answers

Robert Klemme

4/3/2007 4:08:00 PM

On 03.04.2007 17:47, phil.swenson@gmail.com wrote:
> I need to search a specific xml file in a directory, look for:
>
> <port system-property="tangosol.coherence.clusterport">30890</port>
>
> and if the port 30890 is still there replace it with a different
> integer.
>
> I know of several ways to do this (like open the file, iterate the
> lines until I find the integer, do a gsub! on on the integer). But it
> seems like there might be a better way to do it. Is there a search
> and replace API I don't know about?

Look for ruby -pi.bak -e 'gsub ...'

robert

phil swenson

4/3/2007 4:56:00 PM

well I *THOUGHT* I knew how to do it, here's my first crack at it:

file_name = base_config_path + '/Caching/tangosol-
coherence.xml'
File.open(file_name, File::RDWR).each{ |line|
if line.gsub!(/30890/, port.to_s)
puts "tangosol port overridden with %d" % port
break
end
}

The gsub doesn't modify the line, guess it just modifies the string.
How do I actually modify the file itself?

btw, I did look at rexml but it looked like overkill for this. I'll
take another look though.

Robert Klemme

4/3/2007 5:00:00 PM

On 03.04.2007 18:56, phil.swenson@gmail.com wrote:
> well I *THOUGHT* I knew how to do it, here's my first crack at it:
>
> file_name = base_config_path + '/Caching/tangosol-
> coherence.xml'
> File.open(file_name, File::RDWR).each{ |line|
> if line.gsub!(/30890/, port.to_s)
> puts "tangosol port overridden with %d" % port
> break
> end
> }
>
>
> The gsub doesn't modify the line, guess it just modifies the string.

Exactly.

> How do I actually modify the file itself?

Read it, modify it, write it. Or use ruby -pi.bak ...

robert

Robert Evans

4/4/2007 7:39:00 PM

gsub! is destructive - it edits in-place and does not return a value.
You could get a value back from gsub, but then you'd need to do
something with that value.

The following worked, though I don't consider it elegant:

require 'fileutils'

File.open("/tmp/replaceable2.txt", 'w+') do | new_file |
new_file.puts(File.open('/tmp/replaceable.txt', 'r') do |
original_file |
original_file.read.gsub('30890', '44444')
end)
end
FileUtils.mv("/tmp/replaceable2.txt", "/tmp/replaceable.txt")

If you don't want the intermediate file, you could do something like
this:

new_str = File.open('/tmp/replaceable.txt', 'r') { | f | f.read.gsub
('30890', '44444') }
File.open('/tmp/replaceable.txt', w+) { |f| f.puts new_str }

Bob
http://www.junitfa...

On Apr 3, 2007, at 10:00 AM, phil.swenson@gmail.com wrote:

> well I *THOUGHT* I knew how to do it, here's my first crack at it:
>
> file_name = base_config_path + '/Caching/tangosol-
> coherence.xml'
> File.open(file_name, File::RDWR).each{ |line|
> if line.gsub!(/30890/, port.to_s)
> puts "tangosol port overridden with %d" % port
> break
> end
> }
>
>
> The gsub doesn't modify the line, guess it just modifies the string.
> How do I actually modify the file itself?
>
> btw, I did look at rexml but it looked like overkill for this. I'll
> take another look though.
>
>

Robert Evans

4/4/2007 7:45:00 PM

Actually, that was pretty sloppy, by opening the file in read-write
mode, and then rewinding after the read, we can overwrite it with the
changes in a one-liner:

File.open("/tmp/replaceable.txt", 'r+') { |f| newstr = f.read.gsub
('33333', '00000'); f.rewind; f.puts(newstr) }

Bob

On Apr 4, 2007, at 12:39 PM, Robert Evans wrote:

> gsub! is destructive - it edits in-place and does not return a
> value. You could get a value back from gsub, but then you'd need to
> do something with that value.
>
> The following worked, though I don't consider it elegant:
>
> require 'fileutils'
>
> File.open("/tmp/replaceable2.txt", 'w+') do | new_file |
> new_file.puts(File.open('/tmp/replaceable.txt', 'r') do |
> original_file |
> original_file.read.gsub('30890',
> '44444')
> end)
> end
> FileUtils.mv("/tmp/replaceable2.txt", "/tmp/replaceable.txt")
>
> If you don't want the intermediate file, you could do something
> like this:
>
> new_str = File.open('/tmp/replaceable.txt', 'r') { | f | f.read.gsub
> ('30890', '44444') }
> File.open('/tmp/replaceable.txt', w+) { |f| f.puts new_str }
>
> Bob
> http://www.junitfa...
>
>
>
> On Apr 3, 2007, at 10:00 AM, phil.swenson@gmail.com wrote:
>
>> well I *THOUGHT* I knew how to do it, here's my first crack at it:
>>
>> file_name = base_config_path + '/Caching/tangosol-
>> coherence.xml'
>> File.open(file_name, File::RDWR).each{ |line|
>> if line.gsub!(/30890/, port.to_s)
>> puts "tangosol port overridden with %d" % port
>> break
>> end
>> }
>>
>>
>> The gsub doesn't modify the line, guess it just modifies the string.
>> How do I actually modify the file itself?
>>
>> btw, I did look at rexml but it looked like overkill for this. I'll
>> take another look though.
>>
>>
>
>

Robert Evans

4/4/2007 7:50:00 PM

And note, this won't erase any left over old file contents that
extend beyond the length of the current file, e.g., if the port
number is a shorter number of characters than the old port number.

Bob

On Apr 4, 2007, at 12:44 PM, Robert Evans wrote:

> Actually, that was pretty sloppy, by opening the file in read-write
> mode, and then rewinding after the read, we can overwrite it with
> the changes in a one-liner:
>
> File.open("/tmp/replaceable.txt", 'r+') { |f| newstr = f.read.gsub
> ('33333', '00000'); f.rewind; f.puts(newstr) }
>
> Bob
>
>
> On Apr 4, 2007, at 12:39 PM, Robert Evans wrote:
>
>> gsub! is destructive - it edits in-place and does not return a
>> value. You could get a value back from gsub, but then you'd need
>> to do something with that value.
>>
>> The following worked, though I don't consider it elegant:
>>
>> require 'fileutils'
>>
>> File.open("/tmp/replaceable2.txt", 'w+') do | new_file |
>> new_file.puts(File.open('/tmp/replaceable.txt', 'r') do |
>> original_file |
>> original_file.read.gsub('30890',
>> '44444')
>> end)
>> end
>> FileUtils.mv("/tmp/replaceable2.txt", "/tmp/replaceable.txt")
>>
>> If you don't want the intermediate file, you could do something
>> like this:
>>
>> new_str = File.open('/tmp/replaceable.txt', 'r') { | f |
>> f.read.gsub('30890', '44444') }
>> File.open('/tmp/replaceable.txt', w+) { |f| f.puts new_str }
>>
>> Bob
>> http://www.junitfa...
>>
>>
>>
>> On Apr 3, 2007, at 10:00 AM, phil.swenson@gmail.com wrote:
>>
>>> well I *THOUGHT* I knew how to do it, here's my first crack at it:
>>>
>>> file_name = base_config_path + '/Caching/tangosol-
>>> coherence.xml'
>>> File.open(file_name, File::RDWR).each{ |line|
>>> if line.gsub!(/30890/, port.to_s)
>>> puts "tangosol port overridden with %d" % port
>>> break
>>> end
>>> }
>>>
>>>
>>> The gsub doesn't modify the line, guess it just modifies the string.
>>> How do I actually modify the file itself?
>>>
>>> btw, I did look at rexml but it looked like overkill for this. I'll
>>> take another look though.
>>>
>>>
>>
>>
>
>

Emmanuel Oga

4/4/2007 7:54:00 PM

def ChangeOnFile(file, regex_to_find, text_to_put_in_place)
text= File.read file
File.open(file, 'w+'){|f| f << text.gsub(regex_to_find,
text_to_put_in_place)}
end

Then:

ChangeOnFile('/etc/myfile.conf', /30890/, "32737")

Phil Swenson wrote:
> I need to search a specific xml file in a directory, look for:
>
> <port system-property="tangosol.coherence.clusterport">30890</port>
>
> and if the port 30890 is still there replace it with a different
> integer.
>
> I know of several ways to do this (like open the file, iterate the
> lines until I find the integer, do a gsub! on on the integer). But it
> seems like there might be a better way to do it. Is there a search
> and replace API I don't know about?
>
> Any thoughts?

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search a file and replace text

phil swenson

Robert Klemme

phil swenson

Robert Klemme

Robert Evans

Robert Evans

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