в 10:37, 26 мая 2010

2010-05-26T10:37:30Z

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2010-05-26T07:07:40Z

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==Capturing with nested parentheses==



<source lang="html4strict">

<?
if (preg_match("/^(\d{5})(-(\d{4}))?$/",$_POST["zip"],$matches)) {
print "The beginning of the ZIP Code is: $matches[1]\n";
if (isset($matches[2])) {
print "The ZIP+4 is: $matches[3]";
}
}
?>

</source>

==Capturing with preg_match()==



<source lang="html4strict">

<?
if (preg_match("/^(\d{5})(-\d{4})?$/",$_POST["zip"],$matches)) {
print "$matches[0] is a valid US ZIP Code\n";
print "$matches[1] is the five-digit part of the ZIP Code\n";
if (isset($matches[2])) {
print "The ZIP+4 is $matches[2];";
} else {
print "There is no ZIP+4";
}
}
$is_bold = preg_match("@([^<]+)@",$html,$matches);
if ($is_bold) {
print "The bold text is: $matches[1]";
}
?>

</source>

==Checking the syntax of an e-mail address==



<source lang="html4strict">

if (! preg_match("/^[^@\s]+@([-a-z0-9]+\.)+[a-z]{2,}$/i", $_POST["email"])) {
$errors[] = "Please enter a valid e-mail address";
}

</source>

==Check quotes in a file==



<source lang="html4strict">

<?php
$file = fopen("data.txt", "r") or die("Cannot open file!\n");
$lineNbr = 0;
while ($line = fgets($file, 1024)) {
$lineNbr++;
if (preg_match("/^[^\"]*\"([^\"]*|([^\"]*\"[^\"]*\"[^\"]*)*)$/", $line)) {
echo "Found match at line " . $lineNbr . ": " . $line;
}
}
fclose($file);
?>

</source>

==Combine patterns with the pipe (|) character to create branches==



<source lang="html4strict">

<?
$test = "www.example.ru";
if ( preg_match( "/www\.example(\.ru|\.co\.uk)/", $test, $array ) ) {
print "it is a $array[1] domain ";
}
?>

</source>

==Detecting ZIP Codes in Strings==



<source lang="html4strict">

<?php
function detect_zipcode($string) {
return preg_match("/\b\d{5}(-\d{4})?\b/", $string);
}
echo "<pre>";
if (detect_zipcode("MD 11101-3883")) {
echo "Test 1: true\n";
}
if (detect_zipcode("The zipcode 26623 is the area in which I grew up.")) {
echo "Test 2: true\n";
}
if (detect_zipcode("The Phone Number is 301-555-1212")) {
echo "Test 3: true\n";
}
if (detect_zipcode("426969-313109")) {
echo "Test 4: true\n";
}
echo "</pre>";
?>

</source>

==Efficiently finding lines that match a pattern==



<source lang="html4strict">

<?
$fh = fopen("/path/to/your/file.txt", "r") or die($php_errormsg);
while (!feof($fh)) {
$line = fgets($fh);
if (preg_match($pattern, $line)) { $ora_books[ ] = $line; }
}
fclose($fh);
?>

</source>

==Finding All Matching Lines in a File==



<source lang="html4strict">

<?php
$file = fopen("testfile.txt", "r") or die("Cannot open file!\n");
while ($line = fgets($file, 1024)) {
if (preg_match("/Hello( World!)?/", $line)) {
echo "Found match: " . $line;
} else {
echo "No match: " . $line;
}
}
fclose($file);
?>

</source>

==Finding Lines with an Odd Number of Quotes==



<source lang="html4strict">

<?php
$file = fopen("data.txt", "r") or die("Cannot open file!\n");
$lineNbr = 0;
while ($line = fgets($file, 1024)) {
$lineNbr++;
if (preg_match("/^[^\"]*\"([^\"]*|([^\"]*\"[^\"]*\"[^\"]*)*)$/", $line)) {
echo "Found match at line " . $lineNbr . ": " . $line;
}
}
fclose($file);
?>

</source>

==Finding Repeated Words==



<source lang="html4strict">

<?php
function showMatchResults($str) {
if (preg_match("/\b(\w+)\s+\\1\b/i", $str)) {
echo "Match successful: "" . $str . ""\n";
} else {
echo "Match failed: "" . $str . ""\n";
}
}
showMatchResults("Hello World!");
?>

</source>

==Finding the nth Occurrence of a Match==



<source lang="html4strict">

<?php
preg_match("/\d/", "1 and 2 and 3 and 4", $matches);
echo "Value: " . $matches[0][2] . "\n";
?>

</source>

==Finding Words Not Followed by Other Words==



<source lang="html4strict">

<?php
$regex = "/\bhello\b(?!\sworld\b)/";
$valid = "hello";
$invalid = "hello world!";
if (preg_match($regex, $valid)) {
echo "Found match: "" . $valid . ""\n";
} else {
echo "No match: "" . $valid . ""\n";
}
if (preg_match($regex, $invalid)) {
echo "Found match: "" . $invalid . ""\n";
} else {
echo "No match: "" . $invalid . ""\n";
}
?>

</source>

==Find the first "p" string and match as many characters as possible until the last possible "t" is reached.==



<source lang="html4strict">

<?
$text = "pot post pat patent";
if (preg_match ( "/p.*t/", $text, $array ) ) {
print "<pre>\n";
print_r( $array );
print "</pre>\n";
}
?>

</source>

==Get the start and end of the string when m is enabled, you should use \A and \z, like this:==



<source lang="html4strict">

preg_match("/\AThis/m", $multitest);
// returns true if the string starts with "This" (true)
preg_match("/symbol\z/m", $multitest);
// returns true if the string ends with "symbol" (false)

</source>

==i renders the regular expression non case sensitive==



<source lang="html4strict">

<?php
$s = "Another beautiful day";
echo (preg_match ("/BEautiFul/i", $s) ? "MATCH" : "NO MATCH") . "\n";
?>

</source>

==Looking for any lowercase alphabetical character or the numbers 3, 4, and 7==



<source lang="html4strict">

<?
if ( preg_match("/[a-z347]+/", "AB asdf123123asdfasdf", $array) ) {
print "<pre>\n";
print_r( $array );
print "</pre>\n";
}
?>

</source>

==Matching Patterns with preg_match()==



<source lang="html4strict">

preg_match() accepts four arguments:
a regular expression string,
a source string,
an array variable (which stores matches),
and an optional fourth flag argument.

preg_match() returns 0 if a match is found and 1 otherwise.
These numbers represent the number of matches the function can make in a string.

<?
print "<pre>\n";
print preg_match("/is/", "this is a test", $array) . "\n";
print_r( $array );
print "</pre>\n";
?>

</source>

==Matching with preg_match()==



<source lang="html4strict">

<?
if (preg_match("/^\d{5}(-\d{4})?$/",$_POST["zip"])) {
print $_POST["zip"] . " is a valid US ZIP Code";
}
$is_bold = preg_match("@[^<]+@",$html);
?>

</source>

==Negate the characters in the character class==



<source lang="html4strict">

<?
if ( preg_match("/[^a-z347]+/","AB asdf123123asdf", $array) ) {
print "<pre>\n";
print_r( $array );
print "</pre>\n";
}
?>

</source>

==Parsing a date with a regular expression==



<source lang="html4strict">

<?php
$date = "2010-12-03 05:12:56";
preg_match("/(\d{4})-(\d{2})-(\d{2}) (\d{2}):(\d{2}):(\d{2})/",$date,$date_parts);
?>

</source>

==preg_match==



<source lang="html4strict">

<?php
$line = "this is a test!";
if (preg_match("/\bis\b/i", $line, $match)) print "Match found!";
?>

</source>

==preg_match( ) calls and what they match==



<source lang="html4strict">

<?
if (preg_match("/php/i", "PHP")) {
print "Got match!\n";
}
?>

</source>

==preg_match() function returns true if pattern exists, and false otherwise.==



<source lang="html4strict">

Its syntax follows: int preg_match (string pattern, string string [, array pattern_array])
<?
$line = "virtual";
if (preg_match("/\bVi\b/i", $line, $match)) :
print "Match found!";
endif;
?>

</source>

==PREG_OFFSET_CAPTURE and preg_match()==



<source lang="html4strict">

<?php
$s = "It is a beautiful day";
preg_match ("/beautiful/", $s, $matches, PREG_OFFSET_CAPTURE);
var_dump ($matches);
?>

</source>

==Put the word boundary character to the test==



<source lang="html4strict">

<?
$text = "pot post pat patent";
if ( preg_match( "/\bp\w+t\b/", $text, $array ) ) {
print "<pre>\n";
print_r( $array );
print "</pre>\n";
}
?>

</source>

==Regular expressions using +, *, and ?==



<source lang="html4strict">

Regexp Result

preg_match("/[A-Z]+/", "123") False

preg_match("/[A-Z][A-Z0-9]+/i", "A123") True

preg_match("/[0-9]?[A-Z]+/", "10GreenBottles") True; matches "0G"

preg_match("/[0-9]?[A-Z0-9]*/i", "10GreenBottles") True

preg_match("/[A-Z]?[A-Z]?[A-Z]*/", "") True; zero or one match, then zero or one match, then zero or more means that an empty string matches

</source>

==Regular expressions using braces==



<source lang="html4strict">

Regexp Result

preg_match("/[A-Z]{3}/", "FuZ") False; the regexp will match precisely three uppercase letters

preg_match("/[A-Z]{3}/i", "FuZ") True; same as above, but case-insensitive this time

preg_match("/[0-9]{3}-[0-9]{4}/", "555-1234") True; precisely three numbers, a dash, then precisely four. This will match local U.S. telephone numbers, for example

preg_match("/[a-z]+[0-9]?[a-z]{1}/", "aaa1") True; must end with one lowercase letter

preg_match("/[A-Z]{1,}99/", "99") False; must start with at least one uppercase letter

preg_match("/[A-Z]{1,5}99/", "FINGERS99") True; "S99", "RS99", "ERS99", "GERS99", and "NGERS99" all fit the criteria

preg_match("/[A-Z]{1,5}[0-9]{2}/i", "adams42") True

</source>

==s modifier: use . to match characters across multiple lines.==



<source lang="html4strict">

//access the first and last words of a string

<?
$text = "start with this line\nand you will reach\na conclusion in the end\n";
if ( preg_match( "/^(\w+).*?(\w+)$/", $text, $array ) ) {
print "<pre>\n";
print_r( $array );
print "</pre>\n";
}
?>

</source>

==Testing the Complexity of Passwords==



<source lang="html4strict">

<?php
$values = array(
"password", // Bad
"P4ssw0rd", // Good
);
foreach ($values as $value) {
if (! preg_match( "/^(?=.*[A-Z])(?=.*[a-z])(?=.*[0-9]).{8,16}/", $value)) {
printf("Bad password: "%s"\n", $value);
} else {
printf("Good password: "%s"!\n", $value);
}
}
?>

</source>

==Use regular expression to check each line of the code==



<source lang="html4strict">

<?php
$file = fopen("data.txt", "r") or die("Cannot open file!\n");
while ($line = fgets($file, 1024)) {
if (preg_match("/Hello( World!)?/", $line)) {
echo "Found match: " . $line;
} else {
echo "No match: " . $line;
}
}
fclose($file);
?>

</source>

==Using preg_match to return an array of matches that start with ple==



<source lang="html4strict">

<?php
$subject = "example";
$pattern = "/^ple/";
preg_match($pattern, $subject, $matches);
print_r($matches);
?>

</source>

==Validating numbers with regular expressions==



<source lang="html4strict">

<?php
if (! preg_match("/^-?\d+$/"$_POST["rating"])) {
print "Your rating must be an integer.";
}
if (! preg_match("/^-?\d*\.?\d+$/",$_POST["temperature"])) {
print "Your temperature must be a number.";
}
?>

</source>

==Words and Whitespace Regexps==



<source lang="html4strict">

$string = "Foolish child!";
preg_match("/[\S]{7}[\s]{1}[\S]{6}/", $string);

</source>

← Предыдущая	Версия 10:37, 26 мая 2010
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PHP/String/preg match - История изменений

в 10:37, 26 мая 2010

Admin: 1 версия