Re: [Boost-users] Search and replace in text files with Boost.Xpressive

Subject: Re: [Boost-users] Search and replace in text files with Boost.Xpressive
From: Eric Niebler (eric_at_[hidden])
Date: 2011-04-02 03:13:21

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On 4/2/2011 8:23 AM, Júlio Hoffimann wrote:
<snip>
> As far as i know, Boost.Xpressive treats only std::string and C-like
> strings. 

Not so. Both Boost.Xpressive and Boost.Regex work on bidirectional
iterator.

> What i need to do for work with text files? Put them inside a
> std::string?

That's one way. A more efficient way would be to memory-map the file,
which I think you can do portably using Boost.Interprocess. That should
give you a random-access iterator to the source file.

> About the performance, the files has approximately 10^3
> lines, the search and replace will be an issue?

You should use the version of regex_replace that takes an output
iterator, and either write into a string or vector. They both grow their
capacity exponentially (or should if your STL implementation is worth
anything), so this is quite efficient. Or, with an ofstream iterator,
you can write directly to a temporary output file. I think the latest
version of Boost.Filesystem has a portable way to create temporary
files. Then you can do whatever you want with the temp file.

HTH,

- -- 
Eric Niebler
BoostPro Computing
http://www.boostpro.com
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