ereg_replace

(PHP 4, PHP 5)

ereg_replaceSustituye una expresión regular

Advertencia

Esta función está OBSOLETA en PHP 5.3.0, por lo tanto, será ELIMINADA en PHP 7.0.0.

Las alternativas a esta función son:

Descripción

ereg_replace ( string $pattern , string $replacement , string $string ) : string

Esta función busca en string coincidencias de pattern, después reemplaza el texto coincidido con replacement.

Parámetros

pattern

Una expresión regular POSIX extendido.

replacement

Si pattern contiene sub-cadenas entre paréntesis, replacement puede contener sub-cadenas de la forma \dígito, las cuales serán sustituidas por el texto que coincida con la sub-cadena entre paréntesis que coincida con el número marcado por dígito; \0 producirá el contenido completo de la cadena. Se pueden usar hasta nueve sub-cadenas. Los paréntesis se pueden anidar, en cuyo caso son contados por los paréntesis de apertura.

string

La cadena de entrada.

Valores devueltos

Se devuelve la cadena modificada. Si no se encontraron coincidencias en string, éste será devuelto sin cambios.

Ejemplos

Por ejemplo, el siguiente trozo de código imprime "Esto era una prueba" tres veces:

Ejemplo #1 Ejemplo de ereg_replace()

<?php

$cadena 
"Esto es una prueba";
echo 
str_replace(" es"" era"$cadena);
echo 
ereg_replace("( )es""\\1era"$cadena);
echo 
ereg_replace("(( )es)""\\2era"$cadena);

?>

Una cosa a tener en cuenta es que si se usa un valor entero como el parámetro replacement, puede no obtenerse los resultados que se esperaban. Esto es a causa de que ereg_replace() interpretará el número como el valor ordinal de un carácter, y lo aplica. Por ejemplo:

Ejemplo #2 Ejemplo de ereg_replace()

<?php
/* Esto no funcionará como se esperaba. */
$número 4;
$cadena "Esta cadena tiene cuatro palabras.";
$cadena ereg_replace('cuatro'$número$cadena);
echo 
$cadena;   /* Salida: 'Esta cadena tiene   palabras.' */

/* Estó funcionará. */
$número '4';
$cadena "Esta cadena tiene cuatro palabras.";
$cadena ereg_replace('cuatro'$número$cadena);
echo 
$cadena;   /* Salida: 'Esta cadena tiene 4 palabras.' */
?>

Ejemplo #3 Sustituye URLs por vínculos

<?php
$texto 
ereg_replace("[[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/]",
                     
"<a href=\"\0\">\0</a>"$texto);
?>

Ver también

  • ereg() - Comparación de una expresión regular
  • eregi() - Comparación de una expresión regular de forma insensible a mayúsculas-minúsculas
  • eregi_replace() - Sustituye una expresión regular de forma insensible a mayúsculas-minúsculas
  • str_replace() - Reemplaza todas las apariciones del string buscado con el string de reemplazo
  • preg_replace() - Realiza una búsqueda y sustitución de una expresión regular
  • quotemeta() - Escapa meta caracteres

add a note add a note

User Contributed Notes 23 notes

up
1
bjwarshaw2 at yahoo dot com
17 years ago
It's worth mentioning for ultimate clarity that you're safest using double quotes when matching a pattern, since without them, metacharacters will be interpreted as a backslash plus another character.

Granted, this is part of the language syntax for the string type, but it might not be quite so obvious when dealing with patterns in this function, which is taking the pattern as a parameter.

So if you find that '[\n]' is taking the 'n' out of your string and leaving the new lines alone, switch to doubles before changing anything else.
up
1
zaczek at gmail dot com
19 years ago
If you want the function to process query strings, such as:

http://www.php.net/index.php?id=10%32&wp=test

modify the function as follows:

function hyperlink(&$text)
{
   // match protocol://address/path/
   $text = ereg_replace("[a-zA-Z]+://([-]*[.]?[a-zA-Z0-9_/-?&%])*", "<a href=\"\\0\">\\0</a>", $text);

   // match www.something
   $text = ereg_replace("(^| )(www([-]*[.]?[a-zA-Z0-9_/-?&%])*)", "\\1<a href=\"http://\\2\">\\2</a>", $text);
}
up
0
Real PHP Geek
15 years ago
This function makes links unclickable, read the comments:

<?php
function strip_urls($text, $repPat)
{
    if(!
$repPat){
       
$repPat = "text [url]";
    }
   
$aimpstr = 'PHP_STRIP_URLS_FUNCTION_BY_REAL-PHP-GEEK';
   
//change $aimpstr to anything you want.
   
$impstr = md5($aimpstr);
   
$text = str_replace('</a>', '</a>' . $impstr, $text);
   
$text = explode($impstr, $text);
   
$n = 0;
   
$texta = array();
   
$repPat = str_ireplace(array('text', 'url'), array('\\4', '\\2'), $repPat);
    foreach (
$text as $text) {
       
$texta[$n] = ereg_replace("<a(.*)href=\"(.*)\"(.*)>(.*)</a>", $repPat, $text);
       
$n++;
    }
   
$textb = implode("</a>", $texta);
    return
$textb;
}

//EXAMPLES:
$string_of_text = '<a href="http://www.php.net/">PHP</a> rocks. <a href="http://www.apache.org/">Apache</a> also!';
echo
strip_urls($string_of_text, "text");
echo
strip_urls($string_of_text, "url");
echo
strip_urls($string_of_text, "text [url]");
echo
strip_urls($string_of_text, NULL);
?>
up
0
jammin320
16 years ago
Just a quick addition to the last post -

modifying the regular expression for the www clause to include a newline at the begining will allow it to catch URLs that are the first in a line but not the first in a string. The previous version would only catch them if a space preceded the value...

    // match www.something
    $text = ereg_replace("(^| |\n)(www([.]?[a-zA-Z0-9_/-])*)", "\\1<a href=\"http://\\2\">\\2</a>", $text);
up
0
tugla
16 years ago
If you're not relying on regular expressions, str_replace() can be far faster.
up
0
Renjith
16 years ago
Code:

<?php

$s
= "Coding PHP is fun.";

$pattern = "(.*)PHP(.*)";
$replacement = " They say \\1other languages\\2";

print
ereg_replace($pattern, $replacement, $s);

?>

Output:
They say Coding other languages is fun.
Explanation:

"PHP" is replaced with "other languages", and the sentence is changed a little, using \1 and \2 to access the parts within parentheses.
http://php-regex.blogspot.com/
up
0
jarfil at jarfil dot net
17 years ago
For simple patterns like "[a-z]", preg_replace is up to 6 times faster than ereg_replace.
up
0
mephissto at gmail dot com
17 years ago
Your right but you just need to replace by :

<?php
function hyperlink(&$text)
{
   
// match protocol://address/path/
   
$text = ereg_replace("[a-zA-Z]+://([.]?[a-zA-Z0-9_/-])*", "<a href=\"\\0\">\\0</a>", $text);

   
// match www.something
   
$text = ereg_replace("(^| |.)(www([.]?[a-zA-Z0-9_/-])*)", "\\1<a href=\"http://\\2\">\\2</a>", $text);
}
?>
up
0
hoffaboffa (at) hotmail dott com
17 years ago
cristiklein's hyperlink function is nice but works incorrect with a www-string like this

\r\nwww.google.se

then it does not become a hyperlink
up
0
chrish at shield dot on dot ca
18 years ago
I was having problems with Microsoft Outlook viewing forms within email.  I was only able to see the first word of the text box after I used the following code.

If I entered words into the text box and used the enter key to give me a CRLF I could see in the returned data the %0D%0A string, so I assumed if I just used the ereg-replace as below it would just replace the %0D%0A with a single space...

function remove_extra_linebreaks($string) {
   $new_string=ereg_replace("%0D%0A", " ", $string);
  return $new_string;
}

But the form as displayed by Outlook only showed the text upto the first replaced string, then it was blank!
I could view the source of the email and it would show all of the text I expected.

The following will show the correct data in the form

function remove_extra_linebreaks($string) {
   $new_string=ereg_replace("%0D%0A", '+', $string);
  return $new_string;
}
up
0
Chris
18 years ago
I've updated the function a little that was posted below.  I use it to make database field names readable when making a header row.  I needed it to quit putting a space in "GPA" and to put a space in between numbers and letters.

<?php
/**
*  Converts "fieldcontainingGPAInMyDatabaseFrom2005"
*  To       "Field Containing GPA In My Database From 2005"
*/
function innerCapsToReadableText($text) {
   
$text = ereg_replace("([A-Z]) ", "\\1",ucwords(strtolower(ereg_replace("[A-Z]"," \\0",$text))));
    return
ereg_replace("([A-Za-z])([0-9])", "\\1 \\2", $text);
}
?>
up
0
codergeek42 at users dot sourceforge.net
18 years ago
In response to "php dot net at lenix dot de," a cleaner (easier to read) method would be to type-cast the integer as a string by quoting it. For example:

<?php
$foo
= 42;
echo
ereg_replace ( "bar", "$foo" , "foobar" ); /* Would output "foo42". */
?>
up
0
benlanc at ster dot me dot uk
19 years ago
Quite how I managed to get my previous post so wrong, I don't know. Correction follows:
<?php
/* function to turn InterCaps style strings (i.e. CSS Properties in Javascript) to human readable ones */
function deInterCaps($var){
   return
ucfirst(strtolower(ereg_replace("[A-Z]"," \\0",$var)));
}

$interCapsString = "aLoadOfNonsenseToDemonstrateTheFunction";

echo
deInterCaps($interCapsString);

// output: A load of nonsense to demonstrate the function
?>
up
0
php dot net at lenix dot de
19 years ago
One thing to take note of is that if you use an integer value as the replacement parameter, you may not get the results you expect. This is because ereg_replace() will interpret the number as the ordinal value of a character, and apply that.

If you're ever having trouble with this one there's an easy workarround:

instead of
<?php
$foo
= 23;
echo
ereg_replace ( "bar", $foo , "foobar" );
?>

just do

<?php
$foo
= 23;
echo
ereg_replace ( "bar", "" . $foo , "foobar" );
?>

to replace "bar" inside "foobar" with the string "23".
up
0
cristiklein at yahoo dot com
19 years ago
Sometimes, you would like to match both styles of URL links that are common in chat windows:

http://www.yahoo.com
www.yahoo.com

You can do this by using the following code:

<?php
function hyperlink(&$text)
{
   
// match protocol://address/path/
   
$text = ereg_replace("[a-zA-Z]+://([.]?[a-zA-Z0-9_/-])*", "<a href=\"\\0\">\\0</a>", $text);

   
// match www.something
   
$text = ereg_replace("(^| )(www([.]?[a-zA-Z0-9_/-])*)", "\\1<a href=\"http://\\2\">\\2</a>", $text);
}
?>

You can use this function like this:
<?php
$line
= "Check the links: www.yahoo.com http://www.php.net";
hyperlink($line);
// Now, all text that looks like a link becomes a link
?>
up
0
bgoodman at osogrande dot com
19 years ago
When you are dealing with databases you can end up with quite a few \" to deal with.  To ereg_replace all these with something else it requires you to \ the \ and \ the " so you end up with:

$var1 = '\"';
$var2 = ereg_replace('\\\"','1234',$var1);

print $var2;  //this should print 1234
up
0
eerie at gmx dot net
19 years ago
<?php $path = ereg_replace("\\", "/", $path); ?>
as posted from mmtach at yahoo dot com causes an error because you have to escape the backslash twice, once for the quotation marks and a second time due the posix syntax.
<?php $path = ereg_replace("\\\\", "/", $path); ?>
or
<?php $path = ereg_replace('\\', "/", $path); ?>
should both work as expected. since you don't have to escape the backslash in brackets (posix syntax) his alternative works also.
up
-1
computer_guru
16 years ago
Here is the code I use to make links clickable. The code only works on xxxx:// (i.e. ftp://, http://, etc...). It does not work on www. because that is how I want it. The reason my code has an if condition is that it ignores html links and only modifies non-html urls. (see below)

<?php
function make_clickable($text)
{
   
    if (
ereg("[\"|'][[:alpha:]]+://",$text) == false)
    {
       
$text = ereg_replace('([[:alpha:]]+://[^<>[:space:]]+[[:alnum:]/])', '<a target=\"_new\" href="\\1">\\1</a>', $text);
    }
    return(
$text);
}
?>

My function ignores code like this:

<a href="http://php.net"> php.net </a>

But it would make this one click able:

http://php.net
up
-1
bmcswee at gmail dot com dot invalid
17 years ago
Function to strip an HTML tag out of a string. I use this in part for parsing XML documents.

<?php

function stripTags($tag, $string) {
       
// Regular expressions only work with strings if the regexp has been pre-concocted
   
$regExp = "<" . "$tag" . "[^>]*>";

   
$string = str_replace("</$tag>", "", $string);
   
$string = ereg_replace($regExp, "", $string);
   
    return
$string;   
}

?>
up
-1
Joe
14 years ago
Since ereg_replace is now deprecated, many users will be coming to this page, in an attempt to troubleshoot and fix broken scripts after a PHP upgrade.

ereg_replace is essentially a search and replace function and it follows a pattern like this:

<?php

$input
= ereg_replace("find this", "replace it with", $output);

?>

You start out by defining the input variable ($input), then the = ereg_replace portion tells php to do a search and replace action on the value of $input, then once the value has been modified with your 'find this' and 'replace with' section, the resulting value is defined as a variable $output which you can then use in other parts of your script or page.

Lets take a real world example.

There is a e-comm site - http://www.example.com - that has millions of item records.  Each item has a name, that is defined as a variable called $title.  Each $title value has spaces, i.e. "Range Cookers" or "Bosch Dishwashers", but we want to convert these into a page url that does not contain spaces, but uses the plus character '+' instead of a space (you can use hyphens '-' or other characters).

If using the deprecated ereg_replace function, it might look something like this:

<?php

$title
=ereg_replace(" ", "+", $itemurl);

?>

But to avoid those deprecated errors, we change the function name to preg_replace and add a set of delimiters, in this case the 2 forward slashes / / where the contents inside that are matched as the 'find this' portion.

<?php

$title
=preg_replace("/ /", "+", $itemurl);

?>

It is not absolutely necessary to use / / as the delimiters, if you are modifying directory names which may naturally contain forward slashes, it could cause it to break because the slashes in the url or directory would be interpreted as the delimiter, so you could use other obscure characters i.e.  ("# #", "+", $itemurl);  instead.  This would give an output like:

http://www.example.com/-Range+Cooker

http://www.example.com/-Bosch+Dishwasher

This would strip out the spaces from the value of $title and give you a variable called $itemurl where all the spaces were replaced with the plus character, so you could potentially use it as a url like above.

So to summarize:  ereg_replace is a deprecated search and replace action where preg_replace can be used instead, and it follows a pattern as described earlier where it takes the input data, finds a match based on what you are looking for, replaces it with something else you define, and then gives you an output data variable that you can use in your script or page.  Hopefully by understanding the process, the php code functions wont seem like voodoo and you could troubleshoot and fix many of the deprecated errors yourself.
up
-2
lvt
14 years ago
Be careful, don't replace all ereg_replace() with str_replace() as many people will likely to recommend if there is regular expression stuffs, or your script will stop running !!!

Example : replace the (.) at the end of the text with (...)

<?php

$text
= "This is a simple text.";

print(
ereg_replace( "\.$", "...", $text ) );

?>

Test with str_replace() you will find it's not working.
up
-2
http://www.bbgames.co.nr
16 years ago
In response to a post above, his coding was a bit wrong.  The correct coding should be :

<?php
function hyperlink($text)
{
   
// match protocol://address/path/
   
$text = ereg_replace("[a-zA-Z]+://([.]?[a-zA-Z0-9_/-])*", "<a href=\"\\0\">\\0</a>", $text);

   
// match www.something
   
$text = ereg_replace("(^| )(www([.]?[a-zA-Z0-9_/-])*)", "\\1<a href=\"http://\\2\">\\2</a>", $text);

   
// return $text
   
return $text;
}
?>

You can use this function like this:
<?php
$line
= "Check the links: www.yahoo.com http://www.php.net";
hyperlink($line);
// Now, all text that looks like a link becomes a link
?>
up
-3
Anonymous
15 years ago
<?php
// highlights the recognized patterns (a good tool for experiments)

$output = ereg_replace("your regexp here", "<font color=red>\\0</font>", $input)
print
$output;
?>
To Top