ereg

(PHP 4, PHP 5)

ereg — Regular expression match

Description

int ereg ( string $pattern, string $string [, array &$regs] )

Note: preg_match(), which uses a Perl-compatible regular expression syntax, is often a faster alternative to ereg().

Searches a string for matches to the regular expression given in pattern in a case-sensitive way.

If matches are found for parenthesized substrings of pattern and the function is called with the third argument regs, the matches will be stored in the elements of the array regs. $regs[1] will contain the substring which starts at the first left parenthesis; $regs[2] will contain the substring starting at the second, and so on. $regs[0] will contain a copy of the complete string matched.

Note: Up to (and including) PHP 4.1.0 $regs will be filled with exactly ten elements, even though more or fewer than ten parenthesized substrings may actually have matched. This has no effect on ereg()'s ability to match more substrings. If no matches are found, $regs will not be altered by ereg().

Returns the length of the matched string if a match for pattern was found in string, or FALSE if no matches were found or an error occurred. If the optional parameter regs was not passed or the length of the matched string is 0, this function returns 1.

The following code snippet takes a date in ISO format (YYYY-MM-DD) and prints it in DD.MM.YYYY format:

Example 1850. ereg() example


<?php

if (ereg ("([0-9]{4})-([0-9]{1,2})-([0-9]{1,2})", $date, $regs)) {

    echo "$regs[3].$regs[2].$regs[1]";

} else {

    echo "Invalid date format: $date";

}

?>

add a note User Contributed Notes
ereg

jaik at fluidcreativity dot co dot uk
31-Aug-2006 03:41


Here is a fixed version of the UK postcode check function by tomas at phusis dot co dot uk. There was a bug on line 2 of the reg expression where a closing square-bracket was doubled-up ("]]" which should've been "]").



<?php

function IsPostcode($postcode) {

  $postcode = strtoupper(str_replace(chr(32),'',$postcode));

  if(ereg("^(GIR0AA)|(TDCU1ZZ)|((([A-PR-UWYZ][0-9][0-9]?)|"

."(([A-PR-UWYZ][A-HK-Y][0-9][0-9]?)|"

."(([A-PR-UWYZ][0-9][A-HJKSTUW])|"

."([A-PR-UWYZ][A-HK-Y][0-9][ABEHMNPRVWXY]))))"

."[0-9][ABD-HJLNP-UW-Z]{2})$", $postcode))

   return $postcode;

  else

   return FALSE;

}

?>

theppg_001 at hotmail dot com
19-Aug-2006 02:00


Ok well someone else posted this but if didn't work so I made my own.

I used this to check file names that are to be created on a server.

File names that start with a-Z or 0-9 and contain a-Z, 0-9, underscore(_), dash(-), and dot(.) will be accepted.

File names beginning with anything but a-Z or 0-9 will be rejected.

File names  containing anything other than above mentioned will also be rejected.



Here it is.

<?php

$result = ereg("(^[a-zA-Z0-9]+([a-zA-Z\_0-9\.-]*))$" , $filename);

?>

tomas at phusis dot co dot uk
06-Jun-2006 03:41


I could not find a definitive and 100% working function that validates the UK postcodes, so was forced to write one myself.

The authoritative source of information is 



http://www.govtalk.gov.uk/gdsc/html/frames/PostCode.htm



which I amended with the new postcode for Tristan da Cunha.



Here is the ugly beast (don't wanna see regexp's ever again):



<?php

function IsPostcode($postcode) {

  $postcode = strtoupper(str_replace(chr(32),'',$postcode));

  if(ereg("^(GIR0AA)|(TDCU1ZZ)|((([A-PR-UWYZ][0-9][0-9]?)|"

."(([A-PR-UWYZ][A-HK-Y]][0-9][0-9]?)|"

."(([A-PR-UWYZ][0-9][A-HJKSTUW])|"

."([A-PR-UWYZ][A-HK-Y][0-9][ABEHMNPRVWXY]))))"

."[0-9][ABD-HJLNP-UW-Z]{2})$", $postcode))

    return $postcode;

  else

    return FALSE;

}

?>

'morgan'.'galpin'.chr(64).'gmail'.'.com'
11-May-2006 08:16


Try this version instead of the one previously posted.



<?php

  /**

    Returns an array containing each of the sub-strings from text that

    are between openingMarker and closingMarker. The text from 

    openingMarker and closingMarker are not included in the result.

    This function does not support nesting of markers.

  */

  function returnSubstrings($text, $openingMarker, $closingMarker) {

    $openingMarkerLength = strlen($openingMarker);

    $closingMarkerLength = strlen($closingMarker);



    $result = array();

    $position = 0;

    while (($position = strpos($text, $openingMarker, $position)) !== false) {

      $position += $openingMarkerLength;

      if (($closingMarkerPosition = strpos($text, $closingMarker, $position)) !== false) {

        $result[] = substr($text, $position, $closingMarkerPosition - $position);

        $position = $closingMarkerPosition + $closingMarkerLength;

      }

    }

    return $result;

  }

  

  // Example:

  $exampleText = "<b>bonjour</b> à tous, <b>comment</b> allez-vous ?";

  $result = returnSubstrings($exampleText, "<b>", "</b>");

  var_export($result);

  

  // Prints:

  // array (

  //   0 => 'bonjour',

  //   1 => 'comment',

  // )

?>

info at orgied dot com
21-Mar-2006 02:54


Here's a function i've created to return an array of each substring searched in a string.



<?

function Return_Substrings($text, $sopener, $scloser)

                {

                $result = array();

                

                $noresult = substr_count($text, $sopener);

                $ncresult = substr_count($text, $scloser);

                

                if ($noresult < $ncresult)

                        $nresult = $noresult;

                else

                        $nresult = $ncresult;

        

                unset($noresult);

                unset($ncresult);

                

                for ($i=0;$i<$nresult;$i++) 

                        {

                        $pos = strpos($text, $sopener) + strlen($sopener);

                

                        $text = substr($text, $pos, strlen($text));

                

                        $pos = strpos($text, $scloser);

                        

                        $result[] = substr($text, 0, $pos);



                        $text = substr($text, $pos + strlen($scloser), strlen($text));

                        }

                        

                return $result;

                }

?>



Example : 



<?

    $string = "<b>bonjour</b> à tous, <b>comment</b> allez-vous ?";



    $result = Return_Substrings($string, "<b>", "</b>");

?>

psonice (aat) gmail.com
14-Mar-2006 09:39


I wanted a more strict check for UK postcodes, and decided to do it by stripping all whitespace then using ereg:



<?php

$pcode=str_replace(" ","",$in_post_code);

if (!ereg('^[a-zA-Z]{1,2}[0-9]{1,2}[a-zA-Z]{0,1}[0-9]{1}[a-zA-Z]{2}$', $pcode))

{

    return false;

}

?>



Probably could be improved, as I've just started, but it matches everything listed on the post office spec.

ar_cat at shaw dot ca
14-Dec-2005 11:13


I had problem using is_numeric() to verify if user inputs is a number (including optional floating sign and decimals).  Instead I found this expression from http://www.regular-expressions.info/floatingpoint.html and modified it for a bit.



^[+-]?[0-9]*\.?[0-9]+$



/*

3.55      true

-3.55     true

+3.55    true

2456.90  true

34skd    false

23.      false

2dt6      false

*/



Note: mine doesn't have the exponent part; for matching number with exponents, visit the site above :)

net_navard at yahoo dot com
15-Nov-2005 03:35


Hello 



I think this is not clear:



"the matches will be stored in the elements of the array regs. $regs[1] will contain the substring which starts at the first left parenthesis; $regs[2] will contain the substring starting at the second, and so on. $regs[0] will contain a copy of the complete string matched. "



Beacause By "substring," it means the string contained within the parenthesis.



But in that statement it isn't so clearly



With regards



Amir Hossein Estakhrian

Jason Smart knarlin at yahoo dot com dot au
16-Oct-2005 08:13


A common mistake seems to be trying to escape characters within a bracket

expression. Unlike the preg functions, backslash is always taken literally

within a bracket expression using the ereg functions. See

http://php.planetmirror.com/manual/en/function.eregi.php#57824

for more details.



Some of the posts here can be re-written to be much simpler.



16-Feb-2005 10:02

attempts to allow square brackets in a string with

^[a-zA-Z0-9 [.[.] [.].] ]{1,}$

Although this appears to work a less confusing means is

^[]a-zA-Z0-9[]{1,}$

The ] has to be the first character (after a possible ^) but the [ can be

anywhere as long as it is not in the middle of a range of course.



09-Apr-2005 11:52

Says that ereg("hi[:space:]*bob", $string)

doesnt work in php 4 and to use preg_match() instead.



The above quoted use is incorrect it should be

<?php ereg("hi[[:space:]]*bob", $string); ?>



I tested this with the following in php 4.3.3 and it works fine

<?php

//The hex codes are space, tab, line feed, vertical tab, form feed, carriage return

 $whitespace = "\x20\x09\x0a\x0b\x0C\x0d";

 $teststring = "hi".$whitespace."bob";

 $result = ereg ("hi[[:space:]]*bob", $teststring, $arr);

echo ('Matches '.$result.' characters');

//Prints Matches 11 characters

?>



23-May-2005 08:22

Says that ereg("^[' A-Za-Z]+$", $cardName); will not work.



The fault with the above is the range a-Z the capital Z comes before small a

and so this will fail. The following works fine

<?php

$cardname = "John 'Doe'";

$result = ereg("^[' A-Za-z]+$", $cardname, $arr);

echo ('Matches '.$result.' characters');

//Prints Matches 10 characters

?>



09-Sep-2005 11:01

Tries to escape with \ in a bracket expression

You cannot with ereg functions (preg you can) so

ereg("^([-a-zA-Z0-9_\.\!@#\$&\*\+\=\|])*$" , $var)

should be

<?php ereg("^([-a-zA-Z0-9_.!@#$&*+=|])*$", $var); ?>

puremango dot co dot uk at gmail dot com
19-Jul-2005 01:34


for constructing regexes, I recommend 



http://www.weitz.de/regex-coach/



-it highlights the match as you type it!!!

Joel Weierman
22-Jun-2005 07:56


While this is relatively simple example, I was unable find a clean method of doing this anywhere else, so I thought I would post it here. 



As part of a file upload package, I wanted to prevent the uploading of double byte character filenames and other special ASCII characters that may not work well on a Windows and/or Linux system. Here is the statement I ended up using which seems to have done the trick. 



ereg("[^a-zA-Z0-9._-]", $file_name)

irlkersten at gmail dot com
22-Jun-2005 06:54


On a small note to email checking:

Recently it is possible to register domains like www.k�che.de



This would also mean that the IsEMail() function from "php at easy2sync dot com" would report an email address like "contact@k�che.de" as false.



To correct this, use the function below:



function IsEMail($e)

{

    if(eregi("^[a-zA-Z0-9]+[_a-zA-Z0-9-]*

(\.[_a-z0-9-]+)*@[a-z������0-9]+

(-[a-z������0-9]+)*(\.[a-z������0-9-]+)*

(\.[a-z]{2,4})$", $e))

    {

        return TRUE;

    }

    return FALSE;

}

php at REMOVEMEkennel17 dot co dot uk
27-Apr-2005 02:00


After a lot of hard work I managed to create the following regular expression, which matches any HTML tag pair (i.e. opening and closing tag), as specified by tagname:



^(.*)(<[ \n\r\t]*tagname(>|[^>]*>))(.*)(<[ \n\r\t]*/[ \n\r\t]*tagname(>|[^>]*>))(.*)$



The expression is deliberately very forgiving of bad HTML - I wanted to match anything that could be reasonably accepted by a forgiving browser, rather than make it standards compliant. Whitespace is allowed between the tagname and the opening and closing tag symbols, and also between the / and the tagname for the closing tag.



For my own use, I have wrapped it in a function call, which you may find useful.  Here it is with a few notes. I hope somebody finds it useful.



- Mark Clements



<?php 



function ereg_MatchedHTMLTags($tagname) {

    return "^(.*)(<[ \\n\\r\\t]*$tagname(>|[^>]*>))(.*)(<[ \\n\\r\\t]*/[ \\n\\r\\t]*$tagname(>|[^>]*>))(.*)$";

}



// Use with eregi to ensure case-insensitive match.

//        e.g. to split an HTML page based on body tag: 

//             eregi(ereg_MatchedHTMLTags('body'), $Source, $Matches) 



// The following values will be held in $Matches

//(marked values are unintended byproducts of the expression)

//           *[0] - the entire string ($Source).

//            [1] - everything before the opening tag

//            [2] - the opening tag, including all contents (i.e. everything between < and >)

//           *[3] - the opening tag from end of the tag name, 

//                      e.g. '<body bgcolor="#000000">' gives ' bgcolor="#000000">'

//            [4] - the tag contents (everything between the opening and closing tag)

//            [5] - the complete closing tag.

//           *[6] - the closing tag from the end of the tag name

//                      e.g. '</body invalid text>' gives ' invalid text>'

//            [7] - everything after the closing tag.



?>

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Last updated: Fri, 01 Jun 2007