https://github.com/jcreigno/nodejs-file-extractor

Extract data from text files or log files using regular expressions
https://github.com/jcreigno/nodejs-file-extractor

Last synced: 20 days ago
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Extract data from text files or log files using regular expressions

• Host: GitHub
• URL: https://github.com/jcreigno/nodejs-file-extractor
• Owner: jcreigno
• License: mit
• Created: 2012-05-09T22:22:00.000Z (over 12 years ago)
• Default Branch: master
• Last Pushed: 2016-02-27T20:38:51.000Z (over 8 years ago)
• Last Synced: 2024-10-12T10:10:03.846Z (about 1 month ago)
• Language: JavaScript
• Size: 25.4 KB
• Stars: 16
• Watchers: 3
• Forks: 5
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        

file-extractor [![build status](https://secure.travis-ci.org/jcreigno/nodejs-file-extractor.png)](http://travis-ci.org/jcreigno/nodejs-file-extractor) [![NPM version](https://badge.fury.io/js/file-extractor.png)](https://npmjs.org/package/file-extractor)

=========

> Extract data from text files or log files using regular expressions.

introduction

------------

Extractor scans file line by line. Registred callbacks are notified when a patterm matches current line.

synopsis

--------

Start extracting stdin :

```javascript

    var extractor = require('file-extractor');

    extractor().matches(/;(?!(?:[^",]|[^"],[^"])+")/,function(m){

        console.log(m);

    }).start();

```  

Using multiple patterns :

```javascript

    var extractor = require('file-extractor');

    extractor()

        .matches(/regex1/, cb1)

        .matches(/regex2/, cb2)

        .matches(/regex3/, cb3).start();

```  

Using an accumulator :

```javascript

    var extractor = require('file-extractor'),

        fs = require('fs');

    var s = fs.createReadStream(__dirname + '/sample.csv',{});

    extractor({'count': 0}).matches(/;(?!(?:[^",]|[^"],[^"])+")/,function(m, vars){

        console.log(m);

        vars.count ++;

    }).on('end', function(vars){

        console.log(vars.count + ' matches found.');

    }).start(s);

```  

Using an successive match :

```javascript

    var extractor = require('file-extractor'),

        fs = require('fs');

    var s = fs.createReadStream(__dirname + '/sample.csv',{});

    extractor({'count': 0}).matches(/;(?!(?:[^",]|[^"],[^"])+")/g,function(m, vars, files, firstMatch){

        console.log(m);

        vars.count ++;

    }).on('end', function(vars){

        console.log(vars.count + ' matches found.');

    }).start(s);

```  

Using watch mode :

```javascript

    var extractor = require('file-extractor');

    extractor()

        .matches(/regex1/, cb1)

        .matches(/regex2/, cb2)

        .matches(/regex3/, cb3).watch('sample.txt');

```

This mode supports wildcards in file names :

```javascript

    var extractor = require('file-extractor');

    extractor()

        .matches(/regex1/, cb1)

        .matches(/regex2/, cb2)

        .matches(/regex3/, cb3).watch('/var/log/*.log');

```

In this case an additionnal parameter is passed to the callback function to indicate which file triggered the pattern.

```javascript

    var extractor = require('file-extractor');

    extractor()

        .matches(/regex3/, function(match, vars, file){

          console.log('pattern found in : ' + file);

        }).watch('/var/log/*.log');

```

installation

------------

    $ npm install file-extractor

API

===

extractor(ac={}, options={})

----------------

The constructor function creates a new `extractor`. Optionnaly pass an accumulator as parameter.

Accumulator may be used to share data across callbacks.

Options is an object with the folowing attributes :

* successive: [true|false] to enable/disable multiple match on same line.

.matches(regex, callback)

--------------------------

Register a new matching pattern and corresponding callback. Each match is notified using callback. 

* First callback parameter is regex.exec result.

* Second parameter is the accumulator object.

* optionnaly the third parameter is file name (in watch mode).

Return value is `this` to enable method chaining.

.start(readableStream=process.stdin)

------------------------------------

Start scanning stream and notify callbacks. If `readableStream` is empty use standard input `process.stdin`.

.watch(filename)

------------------------------------

Start watching file `filename` for modification, may contains wildcard (see `minimatch` by @izs). Each new lines will trigger matching callbacks.

.close()

------------------------------------

Clean up method. Remove any watcher on file.

Events

======

'end'

-----

Sent when end of stream is reached. The current accumulator is given as first parameter to the event listener. Only emited in no-watch mode (`start` method).

'error'

-----

Sent when watching files with wildcards (`*`) and an error occurred when selecting files. Only emited in watch mode (`watch` method).