?php
//需要匹配的字符串。date函數(shù)返回當(dāng)前時(shí)間
$content = "Current date and time is ".date("Y-m-d h:i a").", we are learning PHP together.";
//使用通常的方法匹配時(shí)間
if (preg_match ("/\d{4}-\d{2}-\d{2} \d{2}:\d{2} [ap]m/", $content, $m))
{
echo "匹配的時(shí)間是：" .$m[0]. "\n";
}
//由于時(shí)間的模式明顯，也可以簡(jiǎn)單的匹配
if (preg_match ("/([\d-]{10}) ([\d:]{5} [ap]m)/", $content, $m))
{
echo "當(dāng)前日期是：" .$m[1]. "\n";
echo "當(dāng)前時(shí)間是：" .$m[2]. "\n";
}
?>

?php
$username = $_SERVER['REMOTE_USER'];
$filename = $_GET['file'];
//對(duì)文件名進(jìn)行過(guò)濾，以保證系統(tǒng)安全
if (!ereg('^[^./][^/]*$', $userfile))
{
die('這不是一個(gè)非法的文件名！');
}
//對(duì)用戶(hù)名進(jìn)行過(guò)濾
if (!ereg('^[^./][^/]*$', $username))
{
die('這不是一個(gè)無(wú)效的用戶(hù)名');
}
//通過(guò)安全過(guò)濾，拼合文件路徑
$thefile = "/home/$username/$filename";
?>

?php
$subjects = array(
"Mechanical Engineering", "Medicine",
"Social Science", "Agriculture",
"Commercial Science", "Politics"
);
//匹配所有僅由有一個(gè)單詞組成的科目名
$alonewords = preg_grep("/^[a-z]*$/i", $subjects);
?>

?php
//功能：將文本中的鏈接地址轉(zhuǎn)成HTML
//輸入：字符串
//輸出：字符串
function url2html($text)
{
//匹配一個(gè)URL，直到出現(xiàn)空白為止
preg_match_all("/http:\/\/?[^\s]+/i", $text, $links);
//設(shè)置頁(yè)面顯示URL地址的長(zhǎng)度
$max_size = 40;
foreach($links[0] as $link_url)
{
//計(jì)算URL的長(zhǎng)度。如果超過(guò)$max_size的設(shè)置，則縮短。
$len = strlen($link_url);
if($len > $max_size)
{
$link_text = substr($link_url, 0, $max_size)."...";
} else {
$link_text = $link_url;
}
//生成HTML文字
$text = str_replace($link_url,"a href='$link_url'>$link_text/a>",$text);
}
return $text;
}
//運(yùn)行實(shí)例
$str = “這是一個(gè)包含多個(gè)URL鏈接地址的多行文字。歡迎訪問(wèn)https://www.jb51.net”;
print url2html($str);
/*輸出結(jié)果
這是一個(gè)包含多個(gè)URL鏈接地址的多行文字。歡迎訪問(wèn)a >
https://www.jb51.net/a>
*/
?>

?php
$rows = file('php.ini'); //將php.ini文件讀到數(shù)組中
//循環(huán)遍歷
foreach($rows as $line)
{
If(trim($line))
{
//將匹配成功的參數(shù)寫(xiě)入數(shù)組中
if(eregi("^([a-z0-9_.]*) *=(.*)", $line, $matches))
{
$options[$matches[1]] = trim($matches[2]);
}
unset($matches);
}
}
//輸出參數(shù)結(jié)果
print_r($options);
?>

?php
$lines = file('source.php'); //將文件讀入數(shù)組中
for($i=0; $icount($lines); $i++)
{
//將行末以“\\”或“#”開(kāi)頭的注釋去掉
$lines[$i] = eregi_replace("(\/\/|#).*$", "", $lines[$i]);
//將行末的空白消除
$lines[$i] = eregi_replace("[ \n\r\t\v\f]*$", "\r\n", $lines[$i]);
}
//整理后輸出到頁(yè)面
echo htmlspecialchars(join("",$lines));
?>

?php
//字符串
$string = "Name: {Name}br>\nEmail: {Email}br>\nAddress: {Address}br>\n";
//模式
$patterns =array(
"/{Address}/",
"/{Name}/",
"/{Email}/"
);
//替換字串
$replacements = array (
"No.5, Wilson St., New York, U.S.A",
"Thomas Ching",
"tom@emailaddress.com",
);
//輸出模式替換結(jié)果
print preg_replace($patterns, $replacements, $string);
?>

?php
$html_body = “HTML>Body>H1>TEST/H1>My PictureImg src=”my.gif”>/Body>/HTML>”;
//輸出結(jié)果中HTML標(biāo)簽將全部為小寫(xiě)字母
echo preg_replace (
"/(\/?)(\w+)([^>]*>)/e",
"'\\1'.strtolower('\\2').'\\3'", //此處的模式變量\\2將被strtolower轉(zhuǎn)換為小寫(xiě)字符
$html_body);
?>

?php
$date = "08/30/2006";
//分隔符可以是斜線，點(diǎn)，或橫線
list($month, $day, $year) = split ('[/.-]', $date);
//輸出為另一種時(shí)間格式
echo "Month: $month; Day: $day; Year: $yearbr />\n";
?>

?php
$seek = array();
$text = "I have a dream that one day I can make it. So just do it, nothing is impossible!";
//將字符串按空白，標(biāo)點(diǎn)符號(hào)拆分（每個(gè)標(biāo)點(diǎn)后也可能跟有空格）
$words = preg_split("/[.,;!\s']\s*/", $text);
foreach($words as $val)
{
$seek[strtolower($val)] ++;
}
echo "共有大約" .count($words). "個(gè)單詞。";
echo "其中共有" .$seek['i']. "個(gè)單詞“I”。";
?>