PHP 常用字符串处理代码片段

移除 HTML 标签

$text = strip_tags($input, "");

　　返回 $start 和 $end 之间的文本

function GetBetween($content,$start,$end){
    $r = explode($start, $content);
    if (isset($r[1])){
        $r = explode($end, $r[1]);
        return $r[0];
    }
    return '';
}

　　将url转换成链接

$url = "Jean-Baptiste Jung (http://www.webdevcat.com)";
$url = preg_replace("#http://([A-z0-9./-]+)#", '<a href="http://www.catswhocode.com/blog/$1" >$0</a>', $url);

　　切分字符串为140个字符

function split_to_chunks($to,$text){
    $total_length = (140 - strlen($to));
    $text_arr = explode(" ",$text);
    $i=0;
    $message[0]="";
    foreach ($text_arr as $word){
        if ( strlen($message[$i] . $word . ' ') <= $total_length ){
            if ($text_arr[count($text_arr)-1] == $word){
                $message[$i] .= $word;
            } else {
                $message[$i] .= $word . ' ';
            }
        } else {
            $i++;
            if ($text_arr[count($text_arr)-1] == $word){
                $message[$i] = $word;
            } else {
                $message[$i] = $word . ' ';
            }
        }
    }
    return $message;
}

　　删除字符串中的URL

$string = preg_replace('/\b(https?|ftp|file):\/\/[-A-Z0-9+&@#\/%?=~_|$!:,.;]*[A-Z0-9+&@#\/%=~_|$]/i', '', $string);

　　将字符串转成SEO友好的字符串

function slug($str){
    $str = strtolower(trim($str));
    $str = preg_replace('/[^a-z0-9-]/', '-', $str);
    $str = preg_replace('/-+/', "-", $str);
    return $str;
}

　　解析 CSV 文件

$fh = fopen("contacts.csv", "r");
while($line = fgetcsv($fh, 1000, ",")) {
    echo "Contact: {$line[1]}";
}

　　字符串搜索

function contains($str, $content, $ignorecase=true){
    if ($ignorecase){
        $str = strtolower($str);
        $content = strtolower($content);
    }
    return strpos($content,$str) ? true : false;
}

　　检查字符串是否以某个串开始

function String_Begins_With($needle, $haystack {
    return (substr($haystack, 0, strlen($needle))==$needle);
}

　　从字符串中提取email地址

function extract_emails($str){
    // This regular expression extracts all emails from a string:
    $regexp = '/([a-z0-9_\.\-])+\@(([a-z0-9\-])+\.)+([a-z0-9]{2,4})+/i';
    preg_match_all($regexp, $str, $m);

    return isset($m[0]) ? $m[0] : array();
}

$test_string = 'This is a test string...

        test1@example.org

        Test different formats:
        test2@example.org;
        <a href="test3@example.org">foobar</a>
        <test4@example.org>

        strange formats:
        test5@example.org
        test6[at]example.org
        test7@example.net.org.com
        test8@ example.org
        test9@!foo!.org

        foobar
';

print_r(extract_emails($test_string));

　　[PHP]代码

function extract_emails($str){
    // This regular expression extracts all emails from a string:
    $regexp = '/([a-z0-9_\.\-])+\@(([a-z0-9\-])+\.)+([a-z0-9]{2,4})+/i';
    preg_match_all($regexp, $str, $m);

    return isset($m[0]) ? $m[0] : array();
}

$test_string = 'This is a test string...

        test1@example.org

        Test different formats:
        test2@example.org;
        <a href="test3@example.org">foobar</a>
        <test4@example.org>

        strange formats:
        test5@example.org
        test6[at]example.org
        test7@example.net.org.com
        test8@ example.org
        test9@!foo!.org

        foobar
';

print_r(extract_emails($test_string));