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For 2023 (and 2024 ...) - we are now fully retired from IT training.
We have made many, many friends over 25 years of teaching about Python, Tcl, Perl, PHP, Lua, Java, C and C++ - and MySQL, Linux and Solaris/SunOS too. Our training notes are now very much out of date, but due to upward compatability most of our examples remain operational and even relevant ad you are welcome to make us if them "as seen" and at your own risk.

Lisa and I (Graham) now live in what was our training centre in Melksham - happy to meet with former delegates here - but do check ahead before coming round. We are far from inactive - rather, enjoying the times that we are retired but still healthy enough in mind and body to be active!

I am also active in many other area and still look after a lot of web sites - you can find an index ((here))
PHP preg functions - examples and comparision

preg_match('%CheckUpdateTime(.*?)Main content end%s',$stuff,$gotten);
preg_match_all('%(<td class="destination">.*?)</tr>%s',$gotten[1],$service);
foreach ($service[1] as $train) {
  $teapot = preg_split('%</td>%',$train);
  foreach ($teapot as $element) {
    $el = preg_replace('%\s+%',' ',trim(strip_tags($element)));
    print "$el\n";
    }
  print "-----------\n";
  }


For this week's course, I have been doing some quite complex data extraction in PHP ... and the example code above uses a number of the major PHP regular expression functions,

Firstly, PHP has an "ereg" family using POSIX regular expressions, and a "preg" family using Perl style. I have used the latter - a little harder to understand at first, but more powerful and stated to be quicker. You may as well take the bull by the horns if you're jumping in!

preg_match creates an array - the whole matched string in the first element, and parts that match bracketed sections of the regular expression in the second (number 1!) and subsequent elements.

preg_match_all works like preg_match but creates a whole array for each element. Slightly surprisingly, the first array within the array is all the full strings, the second array is all the fist matches, etc.

The return values from preg_match and preg_match_all are simply reports of success and not the matched parts, which are in the named array passed in as the third parameter.

preg_split throws away each occurrence of a matching string and returns, as an array, the unmatching string sections in between

preg_replace takes an incoming string and replaces all matches to a particular pattern with an alternative string.

See full source of the example above, which pulls back data from Transport for London and tells you about the next departures from your local tube station!
(written 2009-07-08, updated 2009-07-10)

 
Associated topics are indexed as below, or enter http://melksh.am/nnnn for individual articles
H312 - PHP - Tips and Techniques
  [789] Hot answers in PHP - (2006-07-02)
  [917] Syntax checking in PHP - (2006-11-07)
  [1010] Dates, times, clickable diarys in PHP - (2006-12-28)
  [1270] PHP Standalone - keyboard to screen - (2007-07-18)
  [1649] Easy conversion - image formats, currencies and distances - (2008-05-21)
  [1667] Checking server performance for PHP generated pages - (2008-06-06)
  [1684] Two PHP include files to make easy web site indexing and navigation - (2008-06-21)
  [1958] PHP - Parse error: syntax error, unexpected $end ... - (2008-12-23)
  [1983] Keeping PHP code in database and running it - (2009-01-09)
  [2025] Injection Attack if register_globals in on - PHP - (2009-02-04)
  [2478] How did I do THAT? - (2009-10-26)
  [2981] How to set up short and meaningfull alternative URLs - (2010-10-02)
  [4074] A comment on comments in PHP - (2013-04-28)
  [4310] Problem ... I want to print a series of numbered forms - (2014-10-05)
  [4319] PHP - some quick fixes if scripts have issues, and how to use our support - (2014-11-19)
  [4426] FileMaker Day to Unix Time conversion - (2015-02-15)
  [4621] The power of scripting - (2016-01-12)

H106 - PHP - Arrays
  [409] Functions and commands with dangerous names - (2005-08-11)
  [603] PHP - setting sort order with an associative array - (2006-02-13)
  [773] Breaking bread - (2006-06-22)
  [832] Displaying data at 5 items per line on a web page - (2006-08-14)
  [1116] PHP adding arrays / summing arrays - (2007-03-23)
  [1199] Testing for one of a list of values. - (2007-05-22)
  [1451] More PHP sample and demonstration programs - (2007-12-01)
  [1614] When an array is not an array - (2008-04-17)
  [2215] If nothing, make it nothing. - (2009-06-02)
  [2915] Looking up a value by key - associative arrays / Hashes / Dictionaries - (2010-08-11)
  [2920] Sorting - naturally, or into a different order - (2010-08-14)
  [3004] Increment operators for counting - Perl, PHP, C and others - (2010-10-18)
  [3379] Sorting data the way YOU want it sorted - (2011-08-05)
  [3534] Learning to program in PHP - Regular Expression and Associative Array examples - (2011-12-01)
  [4068] Arrays in PHP - contain different and even mixed data types - (2013-04-24)
  [4072] Splitting the difference with PHP - (2013-04-27)
  [4244] Disambiguation - PHP List - (2014-03-07)


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Python classes / courses - what version do we train on?
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Debugging multipage (session based) PHP applications
PHP preg functions - examples and comparision
Three recent questions on Tomcat Convertors
Monitoring and loading tools for testing Apache Tomcat
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This is a page archived from The Horse's Mouth at http://www.wellho.net/horse/ - the diary and writings of Graham Ellis. Every attempt was made to provide current information at the time the page was written, but things do move forward in our business - new software releases, price changes, new techniques. Please check back via our main site for current courses, prices, versions, etc - any mention of a price in "The Horse's Mouth" cannot be taken as an offer to supply at that price.

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