PageRenderTime 56ms CodeModel.GetById 19ms app.highlight 28ms RepoModel.GetById 1ms app.codeStats 0ms

/user_guide/general/common_functions.html

Relevant Search: With Applications for Solr and Elasticsearch

For more in depth reading about search, ranking and generally everything you could ever want to know about how lucene, elasticsearch or solr work under the hood I highly suggest this book. Easily one of the most interesting technical books I have read in a long time. If you are tasked with solving search relevance problems even if not in Solr or Elasticsearch it should be your first reference. Amazon Affiliate Link
https://bitbucket.org/bo_hmb/bo_hmb
HTML | 776 lines | 679 code | 96 blank | 1 comment | 0 complexity | d798931e4cfa127b8ca1c3a82a86f95e MD5 | raw file
  1
  2
  3<!DOCTYPE html>
  4<!--[if IE 8]><html class="no-js lt-ie9" lang="en" > <![endif]-->
  5<!--[if gt IE 8]><!--> <html class="no-js" lang="en" > <!--<![endif]-->
  6<head>
  7  <meta charset="utf-8">
  8  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  9  
 10  <title>Common Functions &mdash; CodeIgniter 3.1.8 documentation</title>
 11  
 12
 13  
 14  
 15    <link rel="shortcut icon" href="../_static/ci-icon.ico"/>
 16  
 17
 18  
 19  <link href='https://fonts.googleapis.com/css?family=Lato:400,700,400italic,700italic|Roboto+Slab:400,700|Inconsolata:400,700&subset=latin,cyrillic' rel='stylesheet' type='text/css'>
 20
 21  
 22  
 23    
 24
 25  
 26
 27  
 28  
 29    <link rel="stylesheet" href="../_static/css/citheme.css" type="text/css" />
 30  
 31
 32  
 33        <link rel="index" title="Index"
 34              href="../genindex.html"/>
 35        <link rel="search" title="Search" href="../search.html"/>
 36    <link rel="top" title="CodeIgniter 3.1.8 documentation" href="../index.html"/>
 37        <link rel="up" title="General Topics" href="index.html"/>
 38        <link rel="next" title="Compatibility Functions" href="compatibility_functions.html"/>
 39        <link rel="prev" title="Auto-loading Resources" href="autoloader.html"/> 
 40
 41  
 42  <script src="https://cdnjs.cloudflare.com/ajax/libs/modernizr/2.6.2/modernizr.min.js"></script>
 43
 44</head>
 45
 46<body class="wy-body-for-nav" role="document">
 47
 48  <div id="nav">
 49  <div id="nav_inner">
 50    
 51    
 52    
 53      <div id="pulldown-menu" class="ciNav">
 54        <ul>
 55<li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
 56</ul>
 57<ul>
 58<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
 59<li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
 60<li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
 61<li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
 62<li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
 63</ul>
 64</li>
 65</ul>
 66<ul>
 67<li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
 68<li class="toctree-l2"><a class="reference internal" href="../overview/getting_started.html">Getting Started</a></li>
 69<li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
 70<li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
 71<li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
 72<li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
 73<li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
 74</ul>
 75</li>
 76</ul>
 77<ul>
 78<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
 79<li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
 80<li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
 81<li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
 82<li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
 83</ul>
 84</li>
 85</ul>
 86<ul>
 87<li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
 88<li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
 89<li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
 90</ul>
 91</li>
 92</ul>
 93<ul class="current">
 94<li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
 95<li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
 96<li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
 97<li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
 98<li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
 99<li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
100<li class="toctree-l2"><a class="reference internal" href="helpers.html">Helpers</a></li>
101<li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
102<li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
103<li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
104<li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
105<li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
106<li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
107<li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
108<li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
109<li class="toctree-l2 current"><a class="current reference internal" href="#">Common Functions</a></li>
110<li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
111<li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
112<li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
113<li class="toctree-l2"><a class="reference internal" href="caching.html">Caching</a></li>
114<li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
115<li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
116<li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
117<li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
118<li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
119<li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
120<li class="toctree-l2"><a class="reference internal" href="styleguide.html">PHP Style Guide</a></li>
121</ul>
122</li>
123</ul>
124<ul>
125<li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
126<li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
127<li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
128<li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
129<li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
130<li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
131<li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
132<li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
133<li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
134<li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
135<li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
136<li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
137<li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
138<li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
139<li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
140<li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
141<li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
142<li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
143<li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
144<li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
145<li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
146<li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
147<li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
148<li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
149<li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
150<li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
151<li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
152<li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
153<li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
154<li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
155<li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
156</ul>
157</li>
158</ul>
159<ul>
160<li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
161<li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
162<li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
163<li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
164<li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
165<li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
166<li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
167<li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
168<li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
169<li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
170<li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
171<li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
172<li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
173<li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
174<li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
175</ul>
176</li>
177</ul>
178<ul>
179<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
180<li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
181<li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
182<li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
183<li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
184<li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
185<li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
186<li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
187<li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
188<li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
189<li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
190<li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
191<li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
192<li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
193<li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
194<li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
195<li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
196<li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
197<li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
198<li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
199<li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
200<li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
201</ul>
202</li>
203</ul>
204
205      </div>
206    
207      
208  </div>
209</div>
210<div id="nav2">
211  <a href="#" id="openToc">
212    <img src="data:image/jpeg;base64,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" title="Toggle Table of Contents" alt="Toggle Table of Contents" />
213  </a>
214</div>
215
216  <div class="wy-grid-for-nav">
217
218    
219    <nav data-toggle="wy-nav-shift" class="wy-nav-side">
220      <div class="wy-side-nav-search">
221        
222          <a href="../index.html" class="fa fa-home"> CodeIgniter</a>
223        
224        
225<div role="search">
226  <form id="rtd-search-form" class="wy-form" action="../search.html" method="get">
227    <input type="text" name="q" placeholder="Search docs" />
228    <input type="hidden" name="check_keywords" value="yes" />
229    <input type="hidden" name="area" value="default" />
230  </form>
231</div>
232      </div>
233
234      <div class="wy-menu wy-menu-vertical" data-spy="affix" role="navigation" aria-label="main navigation">
235        
236          
237          
238              <ul>
239<li class="toctree-l1"><a class="reference internal" href="welcome.html">Welcome to CodeIgniter</a></li>
240</ul>
241<ul>
242<li class="toctree-l1"><a class="reference internal" href="../installation/index.html">Installation Instructions</a><ul>
243<li class="toctree-l2"><a class="reference internal" href="../installation/downloads.html">Downloading CodeIgniter</a></li>
244<li class="toctree-l2"><a class="reference internal" href="../installation/index.html">Installation Instructions</a></li>
245<li class="toctree-l2"><a class="reference internal" href="../installation/upgrading.html">Upgrading From a Previous Version</a></li>
246<li class="toctree-l2"><a class="reference internal" href="../installation/troubleshooting.html">Troubleshooting</a></li>
247</ul>
248</li>
249</ul>
250<ul>
251<li class="toctree-l1"><a class="reference internal" href="../overview/index.html">CodeIgniter Overview</a><ul>
252<li class="toctree-l2"><a class="reference internal" href="../overview/getting_started.html">Getting Started</a></li>
253<li class="toctree-l2"><a class="reference internal" href="../overview/at_a_glance.html">CodeIgniter at a Glance</a></li>
254<li class="toctree-l2"><a class="reference internal" href="../overview/features.html">Supported Features</a></li>
255<li class="toctree-l2"><a class="reference internal" href="../overview/appflow.html">Application Flow Chart</a></li>
256<li class="toctree-l2"><a class="reference internal" href="../overview/mvc.html">Model-View-Controller</a></li>
257<li class="toctree-l2"><a class="reference internal" href="../overview/goals.html">Architectural Goals</a></li>
258</ul>
259</li>
260</ul>
261<ul>
262<li class="toctree-l1"><a class="reference internal" href="../tutorial/index.html">Tutorial</a><ul>
263<li class="toctree-l2"><a class="reference internal" href="../tutorial/static_pages.html">Static pages</a></li>
264<li class="toctree-l2"><a class="reference internal" href="../tutorial/news_section.html">News section</a></li>
265<li class="toctree-l2"><a class="reference internal" href="../tutorial/create_news_items.html">Create news items</a></li>
266<li class="toctree-l2"><a class="reference internal" href="../tutorial/conclusion.html">Conclusion</a></li>
267</ul>
268</li>
269</ul>
270<ul>
271<li class="toctree-l1"><a class="reference internal" href="../contributing/index.html">Contributing to CodeIgniter</a><ul>
272<li class="toctree-l2"><a class="reference internal" href="../documentation/index.html">Writing CodeIgniter Documentation</a></li>
273<li class="toctree-l2"><a class="reference internal" href="../DCO.html">Developer’s Certificate of Origin 1.1</a></li>
274</ul>
275</li>
276</ul>
277<ul class="current">
278<li class="toctree-l1 current"><a class="reference internal" href="index.html">General Topics</a><ul class="current">
279<li class="toctree-l2"><a class="reference internal" href="urls.html">CodeIgniter URLs</a></li>
280<li class="toctree-l2"><a class="reference internal" href="controllers.html">Controllers</a></li>
281<li class="toctree-l2"><a class="reference internal" href="reserved_names.html">Reserved Names</a></li>
282<li class="toctree-l2"><a class="reference internal" href="views.html">Views</a></li>
283<li class="toctree-l2"><a class="reference internal" href="models.html">Models</a></li>
284<li class="toctree-l2"><a class="reference internal" href="helpers.html">Helpers</a></li>
285<li class="toctree-l2"><a class="reference internal" href="libraries.html">Using CodeIgniter Libraries</a></li>
286<li class="toctree-l2"><a class="reference internal" href="creating_libraries.html">Creating Libraries</a></li>
287<li class="toctree-l2"><a class="reference internal" href="drivers.html">Using CodeIgniter Drivers</a></li>
288<li class="toctree-l2"><a class="reference internal" href="creating_drivers.html">Creating Drivers</a></li>
289<li class="toctree-l2"><a class="reference internal" href="core_classes.html">Creating Core System Classes</a></li>
290<li class="toctree-l2"><a class="reference internal" href="ancillary_classes.html">Creating Ancillary Classes</a></li>
291<li class="toctree-l2"><a class="reference internal" href="hooks.html">Hooks - Extending the Framework Core</a></li>
292<li class="toctree-l2"><a class="reference internal" href="autoloader.html">Auto-loading Resources</a></li>
293<li class="toctree-l2 current"><a class="current reference internal" href="#">Common Functions</a></li>
294<li class="toctree-l2"><a class="reference internal" href="compatibility_functions.html">Compatibility Functions</a></li>
295<li class="toctree-l2"><a class="reference internal" href="routing.html">URI Routing</a></li>
296<li class="toctree-l2"><a class="reference internal" href="errors.html">Error Handling</a></li>
297<li class="toctree-l2"><a class="reference internal" href="caching.html">Caching</a></li>
298<li class="toctree-l2"><a class="reference internal" href="profiling.html">Profiling Your Application</a></li>
299<li class="toctree-l2"><a class="reference internal" href="cli.html">Running via the CLI</a></li>
300<li class="toctree-l2"><a class="reference internal" href="managing_apps.html">Managing your Applications</a></li>
301<li class="toctree-l2"><a class="reference internal" href="environments.html">Handling Multiple Environments</a></li>
302<li class="toctree-l2"><a class="reference internal" href="alternative_php.html">Alternate PHP Syntax for View Files</a></li>
303<li class="toctree-l2"><a class="reference internal" href="security.html">Security</a></li>
304<li class="toctree-l2"><a class="reference internal" href="styleguide.html">PHP Style Guide</a></li>
305</ul>
306</li>
307</ul>
308<ul>
309<li class="toctree-l1"><a class="reference internal" href="../libraries/index.html">Libraries</a><ul>
310<li class="toctree-l2"><a class="reference internal" href="../libraries/benchmark.html">Benchmarking Class</a></li>
311<li class="toctree-l2"><a class="reference internal" href="../libraries/caching.html">Caching Driver</a></li>
312<li class="toctree-l2"><a class="reference internal" href="../libraries/calendar.html">Calendaring Class</a></li>
313<li class="toctree-l2"><a class="reference internal" href="../libraries/cart.html">Shopping Cart Class</a></li>
314<li class="toctree-l2"><a class="reference internal" href="../libraries/config.html">Config Class</a></li>
315<li class="toctree-l2"><a class="reference internal" href="../libraries/email.html">Email Class</a></li>
316<li class="toctree-l2"><a class="reference internal" href="../libraries/encrypt.html">Encrypt Class</a></li>
317<li class="toctree-l2"><a class="reference internal" href="../libraries/encryption.html">Encryption Library</a></li>
318<li class="toctree-l2"><a class="reference internal" href="../libraries/file_uploading.html">File Uploading Class</a></li>
319<li class="toctree-l2"><a class="reference internal" href="../libraries/form_validation.html">Form Validation</a></li>
320<li class="toctree-l2"><a class="reference internal" href="../libraries/ftp.html">FTP Class</a></li>
321<li class="toctree-l2"><a class="reference internal" href="../libraries/image_lib.html">Image Manipulation Class</a></li>
322<li class="toctree-l2"><a class="reference internal" href="../libraries/input.html">Input Class</a></li>
323<li class="toctree-l2"><a class="reference internal" href="../libraries/javascript.html">Javascript Class</a></li>
324<li class="toctree-l2"><a class="reference internal" href="../libraries/language.html">Language Class</a></li>
325<li class="toctree-l2"><a class="reference internal" href="../libraries/loader.html">Loader Class</a></li>
326<li class="toctree-l2"><a class="reference internal" href="../libraries/migration.html">Migrations Class</a></li>
327<li class="toctree-l2"><a class="reference internal" href="../libraries/output.html">Output Class</a></li>
328<li class="toctree-l2"><a class="reference internal" href="../libraries/pagination.html">Pagination Class</a></li>
329<li class="toctree-l2"><a class="reference internal" href="../libraries/parser.html">Template Parser Class</a></li>
330<li class="toctree-l2"><a class="reference internal" href="../libraries/security.html">Security Class</a></li>
331<li class="toctree-l2"><a class="reference internal" href="../libraries/sessions.html">Session Library</a></li>
332<li class="toctree-l2"><a class="reference internal" href="../libraries/table.html">HTML Table Class</a></li>
333<li class="toctree-l2"><a class="reference internal" href="../libraries/trackback.html">Trackback Class</a></li>
334<li class="toctree-l2"><a class="reference internal" href="../libraries/typography.html">Typography Class</a></li>
335<li class="toctree-l2"><a class="reference internal" href="../libraries/unit_testing.html">Unit Testing Class</a></li>
336<li class="toctree-l2"><a class="reference internal" href="../libraries/uri.html">URI Class</a></li>
337<li class="toctree-l2"><a class="reference internal" href="../libraries/user_agent.html">User Agent Class</a></li>
338<li class="toctree-l2"><a class="reference internal" href="../libraries/xmlrpc.html">XML-RPC and XML-RPC Server Classes</a></li>
339<li class="toctree-l2"><a class="reference internal" href="../libraries/zip.html">Zip Encoding Class</a></li>
340</ul>
341</li>
342</ul>
343<ul>
344<li class="toctree-l1"><a class="reference internal" href="../database/index.html">Database Reference</a><ul>
345<li class="toctree-l2"><a class="reference internal" href="../database/examples.html">Quick Start: Usage Examples</a></li>
346<li class="toctree-l2"><a class="reference internal" href="../database/configuration.html">Database Configuration</a></li>
347<li class="toctree-l2"><a class="reference internal" href="../database/connecting.html">Connecting to a Database</a></li>
348<li class="toctree-l2"><a class="reference internal" href="../database/queries.html">Running Queries</a></li>
349<li class="toctree-l2"><a class="reference internal" href="../database/results.html">Generating Query Results</a></li>
350<li class="toctree-l2"><a class="reference internal" href="../database/helpers.html">Query Helper Functions</a></li>
351<li class="toctree-l2"><a class="reference internal" href="../database/query_builder.html">Query Builder Class</a></li>
352<li class="toctree-l2"><a class="reference internal" href="../database/transactions.html">Transactions</a></li>
353<li class="toctree-l2"><a class="reference internal" href="../database/metadata.html">Getting MetaData</a></li>
354<li class="toctree-l2"><a class="reference internal" href="../database/call_function.html">Custom Function Calls</a></li>
355<li class="toctree-l2"><a class="reference internal" href="../database/caching.html">Query Caching</a></li>
356<li class="toctree-l2"><a class="reference internal" href="../database/forge.html">Database Manipulation with Database Forge</a></li>
357<li class="toctree-l2"><a class="reference internal" href="../database/utilities.html">Database Utilities Class</a></li>
358<li class="toctree-l2"><a class="reference internal" href="../database/db_driver_reference.html">Database Driver Reference</a></li>
359</ul>
360</li>
361</ul>
362<ul>
363<li class="toctree-l1"><a class="reference internal" href="../helpers/index.html">Helpers</a><ul>
364<li class="toctree-l2"><a class="reference internal" href="../helpers/array_helper.html">Array Helper</a></li>
365<li class="toctree-l2"><a class="reference internal" href="../helpers/captcha_helper.html">CAPTCHA Helper</a></li>
366<li class="toctree-l2"><a class="reference internal" href="../helpers/cookie_helper.html">Cookie Helper</a></li>
367<li class="toctree-l2"><a class="reference internal" href="../helpers/date_helper.html">Date Helper</a></li>
368<li class="toctree-l2"><a class="reference internal" href="../helpers/directory_helper.html">Directory Helper</a></li>
369<li class="toctree-l2"><a class="reference internal" href="../helpers/download_helper.html">Download Helper</a></li>
370<li class="toctree-l2"><a class="reference internal" href="../helpers/email_helper.html">Email Helper</a></li>
371<li class="toctree-l2"><a class="reference internal" href="../helpers/file_helper.html">File Helper</a></li>
372<li class="toctree-l2"><a class="reference internal" href="../helpers/form_helper.html">Form Helper</a></li>
373<li class="toctree-l2"><a class="reference internal" href="../helpers/html_helper.html">HTML Helper</a></li>
374<li class="toctree-l2"><a class="reference internal" href="../helpers/inflector_helper.html">Inflector Helper</a></li>
375<li class="toctree-l2"><a class="reference internal" href="../helpers/language_helper.html">Language Helper</a></li>
376<li class="toctree-l2"><a class="reference internal" href="../helpers/number_helper.html">Number Helper</a></li>
377<li class="toctree-l2"><a class="reference internal" href="../helpers/path_helper.html">Path Helper</a></li>
378<li class="toctree-l2"><a class="reference internal" href="../helpers/security_helper.html">Security Helper</a></li>
379<li class="toctree-l2"><a class="reference internal" href="../helpers/smiley_helper.html">Smiley Helper</a></li>
380<li class="toctree-l2"><a class="reference internal" href="../helpers/string_helper.html">String Helper</a></li>
381<li class="toctree-l2"><a class="reference internal" href="../helpers/text_helper.html">Text Helper</a></li>
382<li class="toctree-l2"><a class="reference internal" href="../helpers/typography_helper.html">Typography Helper</a></li>
383<li class="toctree-l2"><a class="reference internal" href="../helpers/url_helper.html">URL Helper</a></li>
384<li class="toctree-l2"><a class="reference internal" href="../helpers/xml_helper.html">XML Helper</a></li>
385</ul>
386</li>
387</ul>
388
389          
390        
391      </div>
392      &nbsp;
393    </nav>
394
395    <section data-toggle="wy-nav-shift" class="wy-nav-content-wrap">
396
397      
398      <nav class="wy-nav-top" role="navigation" aria-label="top navigation">
399        <i data-toggle="wy-nav-top" class="fa fa-bars"></i>
400        <a href="../index.html">CodeIgniter</a>
401      </nav>
402
403
404      
405      <div class="wy-nav-content">
406        <div class="rst-content">
407          <div role="navigation" aria-label="breadcrumbs navigation">
408  <ul class="wy-breadcrumbs">
409    <li><a href="../index.html">Docs</a> &raquo;</li>
410      
411        <li><a href="index.html">General Topics</a> &raquo;</li>
412      
413    <li>Common Functions</li>
414    <li class="wy-breadcrumbs-aside">
415      
416    </li>
417    <div style="float:right;margin-left:5px;" id="closeMe">
418      <img title="Classic Layout" alt="classic layout" src="data:image/gif;base64,R0lGODlhFAAUAJEAAAAAADMzM////wAAACH5BAUUAAIALAAAAAAUABQAAAImlI+py+0PU5gRBRDM3DxbWoXis42X13USOLauUIqnlsaH/eY6UwAAOw==" />
419    </div>
420  </ul>
421  <hr/>
422</div>
423          <div role="main" class="document">
424            
425  <div class="section" id="common-functions">
426<h1>Common Functions<a class="headerlink" href="#common-functions" title="Permalink to this headline"></a></h1>
427<p>CodeIgniter uses a few functions for its operation that are globally
428defined, and are available to you at any point. These do not require
429loading any libraries or helpers.</p>
430<div class="custom-index container"></div><dl class="function">
431<dt id="is_php">
432<code class="descname">is_php</code><span class="sig-paren">(</span><em>$version</em><span class="sig-paren">)</span><a class="headerlink" href="#is_php" title="Permalink to this definition"></a></dt>
433<dd><table class="docutils field-list" frame="void" rules="none">
434<col class="field-name" />
435<col class="field-body" />
436<tbody valign="top">
437<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
438<li><strong>$version</strong> (<em>string</em>) – Version number</li>
439</ul>
440</td>
441</tr>
442<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE if the running PHP version is at least the one specified or FALSE if not</p>
443</td>
444</tr>
445<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
446</td>
447</tr>
448</tbody>
449</table>
450<p>Determines if the PHP version being used is greater than the
451supplied version number.</p>
452<p>Example:</p>
453<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nx">is_php</span><span class="p">(</span><span class="s1">&#39;5.3&#39;</span><span class="p">))</span>
454<span class="p">{</span>
455        <span class="nv">$str</span> <span class="o">=</span> <span class="nb">quoted_printable_encode</span><span class="p">(</span><span class="nv">$str</span><span class="p">);</span>
456<span class="p">}</span>
457</pre></div>
458</div>
459<p>Returns boolean TRUE if the installed version of PHP is equal to or
460greater than the supplied version number. Returns FALSE if the installed
461version of PHP is lower than the supplied version number.</p>
462</dd></dl>
463
464<dl class="function">
465<dt id="is_really_writable">
466<code class="descname">is_really_writable</code><span class="sig-paren">(</span><em>$file</em><span class="sig-paren">)</span><a class="headerlink" href="#is_really_writable" title="Permalink to this definition"></a></dt>
467<dd><table class="docutils field-list" frame="void" rules="none">
468<col class="field-name" />
469<col class="field-body" />
470<tbody valign="top">
471<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
472<li><strong>$file</strong> (<em>string</em>) – File path</li>
473</ul>
474</td>
475</tr>
476<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE if the path is writable, FALSE if not</p>
477</td>
478</tr>
479<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
480</td>
481</tr>
482</tbody>
483</table>
484<p><code class="docutils literal"><span class="pre">is_writable()</span></code> returns TRUE on Windows servers when you really can’t
485write to the file as the OS reports to PHP as FALSE only if the
486read-only attribute is marked.</p>
487<p>This function determines if a file is actually writable by attempting
488to write to it first. Generally only recommended on platforms where
489this information may be unreliable.</p>
490<p>Example:</p>
491<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="k">if</span> <span class="p">(</span><span class="nx">is_really_writable</span><span class="p">(</span><span class="s1">&#39;file.txt&#39;</span><span class="p">))</span>
492<span class="p">{</span>
493        <span class="k">echo</span> <span class="s2">&quot;I could write to this if I wanted to&quot;</span><span class="p">;</span>
494<span class="p">}</span>
495<span class="k">else</span>
496<span class="p">{</span>
497        <span class="k">echo</span> <span class="s2">&quot;File is not writable&quot;</span><span class="p">;</span>
498<span class="p">}</span>
499</pre></div>
500</div>
501<div class="admonition note">
502<p class="first admonition-title">Note</p>
503<p class="last">See also <a class="reference external" href="https://bugs.php.net/bug.php?id=54709">PHP bug #54709</a> for more info.</p>
504</div>
505</dd></dl>
506
507<dl class="function">
508<dt id="config_item">
509<code class="descname">config_item</code><span class="sig-paren">(</span><em>$key</em><span class="sig-paren">)</span><a class="headerlink" href="#config_item" title="Permalink to this definition"></a></dt>
510<dd><table class="docutils field-list" frame="void" rules="none">
511<col class="field-name" />
512<col class="field-body" />
513<tbody valign="top">
514<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
515<li><strong>$key</strong> (<em>string</em>) – Config item key</li>
516</ul>
517</td>
518</tr>
519<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Configuration key value or NULL if not found</p>
520</td>
521</tr>
522<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">mixed</p>
523</td>
524</tr>
525</tbody>
526</table>
527<p>The <a class="reference internal" href="../libraries/config.html"><span class="doc">Config Library</span></a> is the preferred way of
528accessing configuration information, however <code class="docutils literal"><span class="pre">config_item()</span></code> can be used
529to retrieve single keys. See <a class="reference internal" href="../libraries/config.html"><span class="doc">Config Library</span></a>
530documentation for more information.</p>
531</dd></dl>
532
533<dl class="function">
534<dt id="set_status_header">
535<code class="descname">set_status_header</code><span class="sig-paren">(</span><em>$code</em><span class="optional">[</span>, <em>$text = ''</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#set_status_header" title="Permalink to this definition"></a></dt>
536<dd><table class="docutils field-list" frame="void" rules="none">
537<col class="field-name" />
538<col class="field-body" />
539<tbody valign="top">
540<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
541<li><strong>$code</strong> (<em>int</em>) – HTTP Response status code</li>
542<li><strong>$text</strong> (<em>string</em>) – A custom message to set with the status code</li>
543</ul>
544</td>
545</tr>
546<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">void</p>
547</td>
548</tr>
549</tbody>
550</table>
551<p>Permits you to manually set a server status header. Example:</p>
552<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">set_status_header</span><span class="p">(</span><span class="mi">401</span><span class="p">);</span>
553<span class="c1">// Sets the header as:  Unauthorized</span>
554</pre></div>
555</div>
556<p><a class="reference external" href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html">See here</a> for
557a full list of headers.</p>
558</dd></dl>
559
560<dl class="function">
561<dt id="remove_invisible_characters">
562<code class="descname">remove_invisible_characters</code><span class="sig-paren">(</span><em>$str</em><span class="optional">[</span>, <em>$url_encoded = TRUE</em><span class="optional">]</span><span class="sig-paren">)</span><a class="headerlink" href="#remove_invisible_characters" title="Permalink to this definition"></a></dt>
563<dd><table class="docutils field-list" frame="void" rules="none">
564<col class="field-name" />
565<col class="field-body" />
566<tbody valign="top">
567<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
568<li><strong>$str</strong> (<em>string</em>) – Input string</li>
569<li><strong>$url_encoded</strong> (<em>bool</em>) – Whether to remove URL-encoded characters as well</li>
570</ul>
571</td>
572</tr>
573<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">Sanitized string</p>
574</td>
575</tr>
576<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">string</p>
577</td>
578</tr>
579</tbody>
580</table>
581<p>This function prevents inserting NULL characters between ASCII
582characters, like Java\0script.</p>
583<p>Example:</p>
584<div class="highlight-ci"><div class="highlight"><pre><span></span><span class="nx">remove_invisible_characters</span><span class="p">(</span><span class="s1">&#39;Java\\0script&#39;</span><span class="p">);</span>
585<span class="c1">// Returns: &#39;Javascript&#39;</span>
586</pre></div>
587</div>
588</dd></dl>
589
590<dl class="function">
591<dt id="html_escape">
592<code class="descname">html_escape</code><span class="sig-paren">(</span><em>$var</em><span class="sig-paren">)</span><a class="headerlink" href="#html_escape" title="Permalink to this definition"></a></dt>
593<dd><table class="docutils field-list" frame="void" rules="none">
594<col class="field-name" />
595<col class="field-body" />
596<tbody valign="top">
597<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
598<li><strong>$var</strong> (<em>mixed</em>) – Variable to escape (string or array)</li>
599</ul>
600</td>
601</tr>
602<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">HTML escaped string(s)</p>
603</td>
604</tr>
605<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">mixed</p>
606</td>
607</tr>
608</tbody>
609</table>
610<p>This function acts as an alias for PHP’s native <code class="docutils literal"><span class="pre">htmlspecialchars()</span></code>
611function, with the advantage of being able to accept an array of strings.</p>
612<p>It is useful in preventing Cross Site Scripting (XSS).</p>
613</dd></dl>
614
615<dl class="function">
616<dt id="get_mimes">
617<code class="descname">get_mimes</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#get_mimes" title="Permalink to this definition"></a></dt>
618<dd><table class="docutils field-list" frame="void" rules="none">
619<col class="field-name" />
620<col class="field-body" />
621<tbody valign="top">
622<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">An associative array of file types</td>
623</tr>
624<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">array</td>
625</tr>
626</tbody>
627</table>
628<p>This function returns a <em>reference</em> to the MIMEs array from
629<em>application/config/mimes.php</em>.</p>
630</dd></dl>
631
632<dl class="function">
633<dt id="is_https">
634<code class="descname">is_https</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#is_https" title="Permalink to this definition"></a></dt>
635<dd><table class="docutils field-list" frame="void" rules="none">
636<col class="field-name" />
637<col class="field-body" />
638<tbody valign="top">
639<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">TRUE if currently using HTTP-over-SSL, FALSE if not</td>
640</tr>
641<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
642</tr>
643</tbody>
644</table>
645<p>Returns TRUE if a secure (HTTPS) connection is used and FALSE
646in any other case (including non-HTTP requests).</p>
647</dd></dl>
648
649<dl class="function">
650<dt id="is_cli">
651<code class="descname">is_cli</code><span class="sig-paren">(</span><span class="sig-paren">)</span><a class="headerlink" href="#is_cli" title="Permalink to this definition"></a></dt>
652<dd><table class="docutils field-list" frame="void" rules="none">
653<col class="field-name" />
654<col class="field-body" />
655<tbody valign="top">
656<tr class="field-odd field"><th class="field-name">Returns:</th><td class="field-body">TRUE if currently running under CLI, FALSE otherwise</td>
657</tr>
658<tr class="field-even field"><th class="field-name">Return type:</th><td class="field-body">bool</td>
659</tr>
660</tbody>
661</table>
662<p>Returns TRUE if the application is run through the command line
663and FALSE if not.</p>
664<div class="admonition note">
665<p class="first admonition-title">Note</p>
666<p class="last">This function checks both if the <code class="docutils literal"><span class="pre">PHP_SAPI</span></code> value is ‘cli’
667or if the <code class="docutils literal"><span class="pre">STDIN</span></code> constant is defined.</p>
668</div>
669</dd></dl>
670
671<dl class="function">
672<dt id="function_usable">
673<code class="descname">function_usable</code><span class="sig-paren">(</span><em>$function_name</em><span class="sig-paren">)</span><a class="headerlink" href="#function_usable" title="Permalink to this definition"></a></dt>
674<dd><table class="docutils field-list" frame="void" rules="none">
675<col class="field-name" />
676<col class="field-body" />
677<tbody valign="top">
678<tr class="field-odd field"><th class="field-name">Parameters:</th><td class="field-body"><ul class="first simple">
679<li><strong>$function_name</strong> (<em>string</em>) – Function name</li>
680</ul>
681</td>
682</tr>
683<tr class="field-even field"><th class="field-name">Returns:</th><td class="field-body"><p class="first">TRUE if the function can be used, FALSE if not</p>
684</td>
685</tr>
686<tr class="field-odd field"><th class="field-name">Return type:</th><td class="field-body"><p class="first last">bool</p>
687</td>
688</tr>
689</tbody>
690</table>
691<p>Returns TRUE if a function exists and is usable, FALSE otherwise.</p>
692<p>This function runs a <code class="docutils literal"><span class="pre">function_exists()</span></code> check and if the
693<cite>Suhosin extension &lt;http://www.hardened-php.net/suhosin/&gt;</cite> is loaded,
694checks if it doesn’t disable the function being checked.</p>
695<p>It is useful if you want to check for the availability of functions
696such as <code class="docutils literal"><span class="pre">eval()</span></code> and <code class="docutils literal"><span class="pre">exec()</span></code>, which are dangerous and might be
697disabled on servers with highly restrictive security policies.</p>
698<div class="admonition note">
699<p class="first admonition-title">Note</p>
700<p class="last">This function was introduced because Suhosin terminated
701script execution, but this turned out to be a bug. A fix
702has been available for some time (version 0.9.34), but is
703unfortunately not released yet.</p>
704</div>
705</dd></dl>
706
707</div>
708
709
710          </div>
711          <footer>
712  
713    <div class="rst-footer-buttons" role="navigation" aria-label="footer navigation">
714      
715        <a href="compatibility_functions.html" class="btn btn-neutral float-right" title="Compatibility Functions">Next <span class="fa fa-arrow-circle-right"></span></a>
716      
717      
718        <a href="autoloader.html" class="btn btn-neutral" title="Auto-loading Resources"><span class="fa fa-arrow-circle-left"></span> Previous</a>
719      
720    </div>
721  
722
723  <hr/>
724
725  <div role="contentinfo">
726    <p>
727        &copy; Copyright 2014 - 2018, British Columbia Institute of Technology.
728      Last updated on Mar 22, 2018.
729    </p>
730  </div>
731
732  Built with <a href="http://sphinx-doc.org/">Sphinx</a> using a <a href="https://github.com/snide/sphinx_rtd_theme">theme</a> provided by <a href="https://readthedocs.org">Read the Docs</a>.
733  
734</footer>
735        </div>
736      </div>
737
738    </section>
739
740  </div>
741  
742
743
744  
745
746    <script type="text/javascript">
747        var DOCUMENTATION_OPTIONS = {
748            URL_ROOT:'../',
749            VERSION:'3.1.8',
750            COLLAPSE_INDEX:false,
751            FILE_SUFFIX:'.html',
752            HAS_SOURCE:  false
753        };
754    </script>
755      <script type="text/javascript" src="../_static/jquery.js"></script>
756      <script type="text/javascript" src="../_static/underscore.js"></script>
757      <script type="text/javascript" src="../_static/doctools.js"></script>
758
759  
760
761  
762  
763    <script type="text/javascript" src="../_static/js/theme.js"></script>
764  
765
766  
767  
768  <script type="text/javascript">
769      jQuery(function () {
770          SphinxRtdTheme.StickyNav.enable();
771      });
772  </script>
773   
774
775</body>
776</html>