strcspn - PHP code example

PHP Function Strcspn - How to Find a String Within a Larger String

php function strcspn is an important and useful tool for finding a string or character within another larger string. This can be useful for a number of reasons, including validating email addresses or verifying the format of a domain name. It’s also a great way to ensure that certain characters are not in a string (like an “@” sign).

There are a few different ways to find a string or character in a larger string. The most common method is to use a string search function, such as srch() or strfind(). These functions are case sensitive, so you will need to make sure that the string or character you want to match is in lowercase.

Other string parsing functions, such as strpos() and strrpos(), return a point in the string where the first occurrence of the character is found. These functions are also case sensitive, so you will need to make

Other methods include using a string replace function, such as preg_replace(str1, str2) or srchreplace(str1, str2). These methods return an array of strings, which can be useful for validating an email address or verifying that a username or password is correct.

strcspn example

$description .= '.';
                }

                $tags['method'][$p] = [$static, $returnType, $signature ?? '()', $description];
                break;
            }
        }

        foreach ($tags['param'] ?? [] as $i => $param) {
            unset($tags['param'][$i]);

            if (\strlen($param) !== strcspn($param, '<{(')) {
                $param = preg_replace('{$([^()]*+|(?R))*$(?: *: *[^ ]++)?|<([^<>]*+|(?R))*>|\{([^{}]*+|(?R))*\}}', '', $param);
            }

            if (false === $i = strpos($param, '$')) {
                continue;
            }

            $type = 0 === $i ? '' : rtrim(substr($param, 0, $i), ' &');
            $param = substr($param, 1 + $i, (strpos($param, ' ', $i) ?: (1 + $i + \strlen($param))) - $i - 1);

            $tags['param'][$param] = $type;
        }

            }

            return $ids;
        }

        public function transliterate(string $string, int $start = 0, int $end = -1): string|false
        {
            $quickCheck = ':' === array_key_first($this->map)[0] ? ':' : self::QUICK_CHECK;

            if (0 === $start && -1 === $end && preg_match('//u', $string)) {
                return \strlen($string) === strcspn($string, $quickCheck) ? $string : strtr($string, $this->map);
            }

            // Here we rely on intl to validate the $string, $start and $end arguments             // and to slice the string. Slicing is done by replacing the part if $string             // between $start and $end by a unique cookie that can be reliably used to             // identify which part of $string should be transliterated.
            static $cookie;
            static $transliterator;

            $cookie ??= hash('xxh128', random_bytes(8));

        return (string) $scalar;
    }

    private static function parseTag(string $value, int &$i, int $flags): ?string
    {
        if ('!' !== $value[$i]) {
            return null;
        }

        $tagLength = strcspn($value, " \t\n[]{},", $i + 1);
        $tag = substr($value, $i + 1, $tagLength);

        $nextOffset = $i + $tagLength + 1;
        $nextOffset += strspn($value, ' ', $nextOffset);

        if ('' === $tag && (!isset($value[$nextOffset]) || \in_array($value[$nextOffset], [']', '}', ','], true))) {
            throw new ParseException('Using the unquoted scalar value "!" is not supported. You must quote it.', self::$parsedLineNumber + 1, $value, self::$parsedFilename);
        }

        // Is followed by a scalar and is a built-in tag         if ('' !== $tag && (!isset($value[$nextOffset]) || !\in_array($value[$nextOffset], ['[', '{'], true)) && ('!' === $tag[0] || \in_array($tag, ['str', 'php/const', 'php/enum', 'php/object'], true))) {

                $values = (array) $values;
            }

            $lcName = strtolower($name);
            $normalizedHeaders[$lcName] = [];

            foreach ($values as $value) {
                $normalizedHeaders[$lcName][] = $value = $name.': '.$value;

                if (\strlen($value) !== strcspn($value, "\r\n\0")) {
                    throw new InvalidArgumentException(sprintf('Invalid header: CR/LF/NUL found in "%s".', $value));
                }
            }
        }

        return $normalizedHeaders;
    }

    /** * @param array|string|resource|\Traversable|\Closure $body * * @return string|resource|\Closure * * @throws InvalidArgumentException When an invalid body is passed */

'application/CDFV2-encrypted',
            'application/zip',
        );

        /* * If $real_mime doesn't match the content type we're expecting from the file's extension, * we need to do some additional vetting. Media types and those listed in $nonspecific_types are * allowed some leeway, but anything else must exactly match the real content type. */
        if ( in_array( $real_mime, $nonspecific_types, true ) ) {
            // File is a non-specific binary type. That's ok if it's a type that generally tends to be binary.             if ( ! in_array( substr( $type, 0, strcspn( $type, '/' ) ), array( 'application', 'video', 'audio' ), true ) ) {
                $type = false;
                $ext  = false;
            }
        } elseif ( str_starts_with( $real_mime, 'video/' ) || str_starts_with( $real_mime, 'audio/' ) ) {
            /* * For these types, only the major type must match the real value. * This means that common mismatches are forgiven: application/vnd.apple.numbers is often misidentified as application/zip, * and some media files are commonly named with the wrong extension (.mov instead of .mp4) */
            if ( substr( $real_mime, 0, strcspn( $real_mime, '/' ) ) !== substr( $type, 0, strcspn( $type, '/' ) ) ) {
                $type = false;

if ($n > 2) {
            $matches += $this->_matchFragment($fragments[2], $this->cpu);
        }
        if ($n > 3) {
            $matches += $this->_matchFragment($fragments[3], $this->extra);
        }
        return ($matches == $n);
    }

    function _matchFragment($fragment, $value)
    {
        if (strcspn($fragment, '*?') < strlen($fragment)) {
            $expression = str_replace(
                array('*', '?', '/'),
                array('.*', '.', '\\/'),
                $fragment
            );
            $reg = '/^' . $expression . '\\z/';
            return preg_match($reg, $value);
        }
        return ($fragment == '*' || !strcasecmp($fragment, $value));
    }
}

// We fail to fail on non US-ASCII bytes         if ($input === 'US-ASCII')
        {
            static $non_ascii_octects = '';
            if (!$non_ascii_octects)
            {
                for ($i = 0x80; $i <= 0xFF; $i++)
                {
                    $non_ascii_octects .= chr($i);
                }
            }
            $data = substr($data, 0, strcspn($data, $non_ascii_octects));
        }

        // This is first, as behaviour of this is completely predictable         if ($input === 'windows-1252' && $output === 'UTF-8')
        {
            return SimplePie_Misc::windows_1252_to_utf8($data);
        }
        // This is second, as behaviour of this varies only with PHP version (the middle part of this expression checks the encoding is supported).         elseif (function_exists('mb_convert_encoding') && ($return = SimplePie_Misc::change_encoding_mbstring($data, $input, $output)))
        {
            return $return;
         }

$output = '';

        while ($position < $length && ($pos = strpos($string, '(', $position)) !== false)
        {
            $output .= substr($string, $position, $pos - $position);
            $position = $pos + 1;
            if ($pos === 0 || $string[$pos - 1] !== '\\')
            {
                $depth++;
                while ($depth && $position < $length)
                {
                    $position += strcspn($string, '()', $position);
                    if ($string[$position - 1] === '\\')
                    {
                        $position++;
                        continue;
                    }
                    elseif (isset($string[$position]))
                    {
                        switch ($string[$position])
                        {
                            case '(':
                                $depth++;

return false;
        }

        // Then remove the DOCTYPE         $header = preg_replace( '/^<!DOCTYPE[^>]*+>/i', '', substr( $this->message, 0, 200 ), 1 );
        $this->message = trim( substr_replace( $this->message, $header, 0, 200 ) );
        if ( '' == $this->message ) {
            return false;
        }

        // Check that the root tag is valid         $root_tag = substr( $this->message, 0, strcspn( substr( $this->message, 0, 20 ), "> \t\r\n" ) );
        if ( '<!DOCTYPE' === strtoupper( $root_tag ) ) {
            return false;
        }
        if ( ! in_array( $root_tag, array( '<methodCall', '<methodResponse', '<fault' ) ) ) {
            return false;
        }

        // Bail if there are too many elements to parse         $element_limit = 30000;
        if ( function_exists( 'apply_filters' ) ) {
            /** * Filters the number of elements to parse in an XML-RPC response. * * @since 4.0.0 * * @param int $element_limit Default elements limit. */

else
        {
            $this->state = false;
        }
    }

    /** * Parse the reason phrase */
    protected function reason()
    {
        $len = strcspn($this->data, "\x0A", $this->position);
        $this->reason = trim(substr($this->data, $this->position, $len), "\x09\x0D\x20");
        $this->position += $len + 1;
        $this->state = 'new_line';
    }

    /** * Deal with a new line, shifting data around as needed */
    protected function new_line()
    {
        $this->value = trim($this->value, "\x0D\x20");

$this->addAliases($aliases);
    }

    /** * Sets an alias for an existing service. * * @throws InvalidArgumentException if the id is not a string or an Alias * @throws InvalidArgumentException if the alias is for itself */
    public function setAlias(string $alias, string|Alias $id): Alias
    {
        if ('' === $alias || '\\' === $alias[-1] || \strlen($alias) !== strcspn($alias, "\0\r\n'")) {
            throw new InvalidArgumentException(sprintf('Invalid alias id: "%s".', $alias));
        }

        if (\is_string($id)) {
            $id = new Alias($id);
        }

        if ($alias === (string) $id) {
            throw new InvalidArgumentException(sprintf('An alias cannot reference itself, got a circular reference on "%s".', $alias));
        }

$expressions = [];

        // An expression which will never match to replace expressions which cannot match in the crawler         // We cannot drop         $nonMatchingExpression = 'a[name() = "b"]';

        $xpathLen = \strlen($xpath);
        $openedBrackets = 0;
        $startPosition = strspn($xpath, " \t\n\r\0\x0B");

        for ($i = $startPosition; $i <= $xpathLen; ++$i) {
            $i += strcspn($xpath, '"\'[]|', $i);

            if ($i < $xpathLen) {
                switch ($xpath[$i]) {
                    case '"':
                    case "'":
                        if (false === $i = strpos($xpath, $xpath[$i], $i + 1)) {
                            return $xpath; // The XPath expression is invalid                         }
                        continue 2;
                    case '[':
                        ++$openedBrackets;

        }
        else
        {
            $ihost = $this->replace_invalid_with_pct_encoding($ihost, '!$&\'()*+,;=');

            // Lowercase, but ignore pct-encoded sections (as they should             // remain uppercase). This must be done after the previous step             // as that can add unescaped characters.             $position = 0;
            $strlen = strlen($ihost);
            while (($position += strcspn($ihost, 'ABCDEFGHIJKLMNOPQRSTUVWXYZ%', $position)) < $strlen)
            {
                if ($ihost[$position] === '%')
                {
                    $position += 3;
                }
                else
                {
                    $ihost[$position] = strtolower($ihost[$position]);
                    $position++;
                }
            }

    public function import(mixed $resource, string $type = null, bool $ignoreErrors = false, string $sourceResource = null, string|array $exclude = null)
    {
        if (\is_string($resource) && \strlen($resource) !== ($i = strcspn($resource, '*?{[')) && !str_contains($resource, "\n")) {
            $excluded = [];
            foreach ((array) $exclude as $pattern) {
                foreach ($this->glob($pattern, true, $_, false, true) as $path => $info) {
                    // normalize Windows slashes and remove trailing slashes                     $excluded[rtrim(str_replace('\\', '/', $path), '/')] = true;
                }
            }

            $ret = [];
            $isSubpath = 0 !== $i && str_contains(substr($resource, 0, $i), '/');
            foreach ($this->glob($resource, false, $_, $ignoreErrors || !$isSubpath, false, $excluded) as $path => $info) {