PHP regular expression pattern matching example tutorial

$sub = "bbs.it-home.org";
$ptn = '/w*.w*.w */';
// Regular expression, metadata, returned data
preg_match($ptn, $sub,$mats);

echo "
";
print_r($mats);
echo "";
?>
//match ip

$str = "my ip is 192.168.10.1sdjlfajdf192 .178.39.4la";
$ptn = '/d+.d+.d+.d+/';
preg_match_all($ptn, $str,$mats);
 echo "
";
print_r($mats);
echo "";
?>

pattern modifier and place it at the end of the regular expression i,m,s,u,e i: ignore case m: Treat as multiple lines s: treated as one line u: Greedy mode, maximum mode e: used when replacing, can be processed with functions, used to match the first parentheses in regular expressions

$str = "Linux and php are lamp or linux is very much";
$ptn = '/linux/i';
preg_match_all($ptn, $str,$mats) ;
echo "";
print_r($mats);
echo "";
?>

mExample m is treated as multiple lines

$str = "Linux and php are lamp or nlinux is very much";
$ptn = '/^linux/im';
preg_match_all($ptn, $str,$mats
echo "";
print_r($mats);
echo "";

$str = "Linux and php are lamp or nlinux is very much"; $ptn = '/.*/s'; preg_match_all($ptn, $str,$mats ); echo "

"; 

Copy code


e usage


$ptn = '/d+s(w+)/e'; 
$rep = 'strtoupper($1)'; 
// preg_match_all ($ptn, $str,$mats); 
echo "
$ptn = '/(d+)(s)(w+)/'; 
$rep = '$3$2$1'; 
// preg_match_all($ptn, $str,$mats); 
echo " pre>";
?>


Copy code


Five commonly used functions
1. String matching and replacement
preg_match();
preg_match_all();
preg_grep(); do a search

2. String replacement
preg_replace();

3. String segmentation
preg_split();
eval allows string expressions to be executed
Preg_grep example, search:


$arr = array( 
"php html", 
" linux redhat rhce", 
$ptn = '/junzaivip/';
//Return the searched content
$arr2 = preg_grep($ptn, $arr);
echo "";
print_r($arr2);
 echo "";
?>


Copy code


4. Mathematical functions
1.max();
2.min();
Note: 1. Multiple numbers, 2. Arrays composed of multiple numbers


echo "
"; 
echo max(array(4,6,8,9)); 
? > 

5.Date function
1.time();
2.date(); //Convert timestamp to date
3.strtotime();//Convert date to timestamp
4.microtime();
 

//calc Open the calculator
The origin of time:

echo time();
echo "";
echo date("Y-m-d H:i-s w t", 0);
?>
Convert time to timestamp
 


cho strtotime("2014-12-12");
?>
 to calculate the specific date of the current time:
 


echo date("Y-m-d H:i:s",time()+8*3600);
?>
Find the current time by modifying the time zone date:
 


//Set China’s time zone as the default time zone
date_default_timezone_set("PRC");
echo date("Y-m-d H:i:s",time());
?>

Note: If each change is troublesome, just modify the php configuration file php.ini file directly, directly modify the date inside, find the timezone and change it to PRC
date parameters:
Y 2014 full year
y In 2014, there were only the last two
m 03 month has leading 0
n March has no leading 0
d 05 date has leading 0
j 5 date without leading 0
H 24 hours
h 12 hours
i 05 minutes
s 05 seconds
w 0-6 Sunday to Saturday
t How many days are there in January 31
L Is it a leap year?
//How to distinguish Pingrun years
It is divisible by 4, and if it is divisible by 100, it must be divisible by 400. At this time, it is a leap year.
 


//Set China’s time zone as the default time zone
date_default_timezone_set("PRC");
$y = "1900/1/1";
$time = strtotime ($y);
echo date("L",$time);
?>


microtime() Microseconds 
Calculate the running time of the script:
 


$stime = microtime(1);//Note that this position must be true, otherwise it cannot participate in the calculation
sleep(1);
$etime = microtime(1);
echo $etime - $stime;
?>
Example: Perpetual calendar
Perpetual calendar technical points
1. Year, month and day
2.Sunday to Saturday
What day of the week is 3.1?
4.How many days are there in this month?
5. Next year and previous year
6.Next month and previous month
Perpetual calendar code:
 


//Modify character encoding
//header("content-type:text/html;charset=utf-8");
date_default_timezone_set("PRC") ;
//Get the current year
$year = $_GET['y']?$_GET['y']:date('Y');
//Get the current month
$month = $_GET['m' ]?$_GET['m']:date('m');
//Get how many days there are in the current month
$days = date('t',strtotime("{$year}-{$month}- 1"));//Double quotes must be used inside
//What day of the week is the current first day?$weeks = date('w',strtotime("{$year}-{$month}-1"));
 //All content is centered
echo ""; //Output header 
echo "{$year}year{$month}month"; 
//Output date Table
echo ""; //Output the first rowecho ""; //The header cell is created by thecho ""; echo ""; echo ""; echo ""; echo ""; echo ""; echo "> ;"; echo ""; //Start laying out the formfor($i = 1 - $weeks;$i echo "";  for ($j=0; $j if ($i > $days || $i echo "";  } else{ echo ""; } $i++; } echo ""; } "; //Realize the previous year and the previous monthif($month == 1){ $prevyear = $year - 1; $prevmonth = 12; } else { $prevyear = $year; $prevmonth = $month -1; } if($month == 12){ $nextyear = $year + 1; $nextmonth = 1; } else{ $ nextyear = $year; $nextmonth = $month + 1; } //Buttons to output the previous month and the next monthecho "
Previous month|Next month
"; echo ""; ?> 
Copy codePHP error deal with
1. Turn off and on error reporting
2. Error reporting level
3. Error reporting place
1), close and enable error reporting
E_ALL
E_ERROR //serious error
E_WARNING //warning error
E_PARSE//Syntax error
E_NOTICE //Prompt error
2), close error
display_error = off
What level of error is reported:
 
error_reporting = E_ALL
error_reporting = E_ALL & ~E_NOTICE //Report all errors except prompt errors
3), where to report errors:
 
//Whether to report an error from the browser
display_error = off
//Whether to output errors to a custom log file
log_errors = on
error_log = d:phplogsphp.log




日
一
二
 three
four
five
six



 

{$i}