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strtok
(PHP 3, PHP 4, PHP 5)
strtok - Разбивает строку
Описание
string strtok ( string arg1, string arg2 )strtok() разбивает строку arg1 на подстроки, используя в качестве разделителей символы из arg2. Например строку "This is an example string" можно разбить на отдельные слова.
Пример 1. Пример использования strtok()
$string = "This is\tan example\nstring";
/* в качестве разделителей используем пробел, табуляцию и перевод строки */
$tok = strtok($string, " \n\t");
while ($tok) {
echo "Word=$tok<br />";
$tok = strtok(" \n\t");
}
Заметьте, что исходная строка передается только при первом вызове этой функции. Последующим вызовам передаются только разделители, так как эта функция сохраняет исходную строку и запоминает позицию в этой строке между вызовами. Для работы с новой строкой нужно снова вызвать функцию с двумя аргументами.
Начиная с PHP 4.1.0, был изменен способ обработки пустых подстрок. До версии 4.1.0 эта функция возвращала пустые подстроки, а начиная с 4.1.0 эти подстроки пропускаются.
Пример 2. Старый способ обработки пустых подстрок функцией strtok()
$first_token = strtok('/something', '/');
$second_token = strtok('/');
var_dump($first_token, $second_token);
Вывод:
Пример 3. Новый способ обработки пустых подстрок функцией strtok()
$first_token = strtok('/something', '/');
$second_token = strtok('/');
var_dump($first_token, $second_token);
Вывод:
Помните также о том, что может быть возвращена подстрока "0". В логических выражениях это значение может соответствовать FALSE.
Пример 4.
/** get leading, trailing, and embedded separator tokens that were 'skipped'
if for some ungodly reason you are using php to implement a simple parser that
needs to detect nested clauses as it builds a parse tree */
$str = "(((alpha(beta))(gamma))";
$seps = '()';
$tok = strtok( $str,$seps ); // return false on empty string or null
$cur = 0;
$dumbDone = FALSE;
$done = (FALSE===$tok);
while (!$done) {
// process skipped tokens (if any at first iteration) (special for last)
$posTok = $dumbDone ? strlen($str) : strpos($str, $tok, $cur );
$skippedMany = substr( $str, $cur, $posTok-$cur ); // false when 0 width
$lenSkipped = strlen($skippedMany); // 0 when false
if (0!==$lenSkipped) {
$last = strlen($skippedMany) -1;
for($i=0; $i<=$last; $i++){
$skipped = $skippedMany[$i];
$cur += strlen($skipped);
echo "skipped: $skipped\n";
}
}
if ($dumbDone) break; // this is the only place the loop is terminated
// process current tok
echo "curr tok: ".$tok."\n";
// update cursor
$cur += strlen($tok);
// get any next tok
if (!$dumbDone){
$tok = strtok($seps);
$dumbDone = (FALSE===$tok);
// you're not really done till you check for trailing skipped
}
};
Пример 5.
#_____________________
# parse_cli($string) /
function parse_cli($string) {
$state = 'space';
$previous = ''; // stores current state when encountering a backslash (which changes $state to 'escaped', but has to fall back into the previous $state afterwards)
$out = array(); // the return value
$word = '';
$type = ''; // type of character
// array[states][chartypes] => actions
$chart = array(
'space' => array('space'=>'', 'quote'=>'q', 'doublequote'=>'d', 'backtick'=>'b', 'backslash'=>'ue', 'other'=>'ua'),
'unquoted' => array('space'=>'w ', 'quote'=>'a', 'doublequote'=>'a', 'backtick'=>'a', 'backslash'=>'e', 'other'=>'a'),
'quoted' => array('space'=>'a', 'quote'=>'w ', 'doublequote'=>'a', 'backtick'=>'a', 'backslash'=>'e', 'other'=>'a'),
'doublequoted' => array('space'=>'a', 'quote'=>'a', 'doublequote'=>'w ', 'backtick'=>'a', 'backslash'=>'e', 'other'=>'a'),
'backticked' => array('space'=>'a', 'quote'=>'a', 'doublequote'=>'a', 'backtick'=>'w ', 'backslash'=>'e', 'other'=>'a'),
'escaped' => array('space'=>'ap', 'quote'=>'ap', 'doublequote'=>'ap', 'backtick'=>'ap', 'backslash'=>'ap', 'other'=>'ap'));
for ($i=0; $i<=strlen($string); $i++) {
$char = substr($string, $i, 1);
$type = array_search($char, array('space'=>' ', 'quote'=>'\'', 'doublequote'=>'"', 'backtick'=>'`', 'backslash'=>'\\'));
if (! $type) $type = 'other';
if ($type == 'other') {
// grabs all characters that are also 'other' following the current one in one go
preg_match("/[ \'\"\`\\\]/", $string, $matches, PREG_OFFSET_CAPTURE, $i);
if ($matches) {
$matches = $matches[0];
$char = substr($string, $i, $matches[1]-$i); // yep, $char length can be > 1
$i = $matches[1] - 1;
}else{
// no more match on special characters, that must mean this is the last word!
// the .= hereunder is because we *might* be in the middle of a word that just contained special chars
$word .= substr($string, $i);
break; // jumps out of the for() loop
}
}
$actions = $chart[$state][$type];
for($j=0; $j<strlen($actions); $j++) {
$act = substr($actions, $j, 1);
if ($act == ' ') $state = 'space';
if ($act == 'u') $state = 'unquoted';
if ($act == 'q') $state = 'quoted';
if ($act == 'd') $state = 'doublequoted';
if ($act == 'b') $state = 'backticked';
if ($act == 'e') { $previous = $state; $state = 'escaped'; }
if ($act == 'a') $word .= $char;
if ($act == 'w') { $out[] = $word; $word = ''; }
if ($act == 'p') $state = $previous;
}
}
if (strlen($word)) $out[] = $word;
return $out;
}
Пример 6.
/**
* The TokenIterator class allows you to iterate through string tokens using
* the familiar foreach control structure.
*
* Example:
*
*/
class TokenIterator implements Iterator
{
/**
* The string to tokenize.
* @var string
*/
protected $_string;
/**
* The token delimiters.
* @var string
*/
protected $_delims;
/**
* Stores the current token.
* @var mixed
*/
protected $_token;
/**
* Internal token counter.
* @var int
*/
protected $_counter = 0;
/**
* Constructor.
*
* @param string $string The string to tokenize.
* @param string $delims The token delimiters.
*/
public function __construct($string, $delims)
{
$this->_string = $string;
$this->_delims = $delims;
$this->_token = strtok($string, $delims);
}
/**
* @see Iterator::current()
*/
public function current()
{
return $this->_token;
}
/**
* @see Iterator::key()
*/
public function key()
{
return $this->_counter;
}
/**
* @see Iterator::next()
*/
public function next()
{
$this->_token = strtok($this->_delims);
if ($this->valid()) {
++$this->_counter;
}
}
/**
* @see Iterator::rewind()
*/
public function rewind()
{
$this->_counter = 0;
$this->_token = strtok($this->_string, $this->_delims);
}
/**
* @see Iterator::valid()
*/
public function valid()
{
return $this->_token !== FALSE;
}
}
Пример 7.
$str=str_repeat('foo ',10000);
//explode()
$time=microtime(TRUE);
$arr=explode($str,' ');
$time=microtime(TRUE)-$time;
echo "explode():$time sec.".PHP_EOL;
//strtok()
$time=microtime(TRUE);
$ret=strtok(' ',$str);
while($ret!==FALSE){
$ret=strtok(' ');
}
$time=microtime(TRUE)-$time;
echo "strtok():$time sec.".PHP_EOL;
Пример 8.
for($tok = strtok($str, ' _-.'); $tok!==false; $tok = strtok(' _-.'))
{
echo "$tok </br>";
}
Пример 9.
$text = "13 202 5 This is a long message explaining the error codes.";
$error1 = strtok($text, " "); //13
$error2 = strtok(" "); //202
$error3 = strtok(" "); //5
$error_message = strtok(""); //Notice the different token parameter
echo $error_message; //This is a long message explaining the error codes.
Пример 10.
function tokenize($str, $token_symbols) {
$word = strtok($str, $token_symbols);
while (false !== $word) {
// do something here...
$word = strtok($token_symbols);
}
}
Пример 11.
$token = strtok($keywords,' ');
while ($token) {
// find double quoted tokens
if ($token{0}=='"') { $token .= ' '.strtok('"').'"'; }
// find single quoted tokens
if ($token{0}=="'") { $token .= ' '.strtok("'")."'"; }
$tokens[] = $token;
$token = strtok(' ');
}
Пример 12.
/**
* The string tokenizer class allows an application to break a string into tokens.
* @example The following is one example of the use of the tokenizer. The code:
*/
$str = 'this is:@\t\n a test!';
$delim = ' !@:'\t\n; // remove these chars
$st = new StringTokenizer($str, $delim);
while ($st->hasMoreTokens()) {
echo $st->nextToken() . "\n";
}
prints the following output: this is a test
Пример 13.
header('Content-type: text/plain; charset=utf-8');
/**
* NOTE : use mbstring.func_overload for multi-byte support with this function
*
* @param string $string the string to tokenize
* @param int $offset the starting offset
* @param string $defaultTokenName the default token name if none specified
* @param string $groupDelimiters the characters to delimit token groups
* @param string $groupNameDelimiter the character(s) to delimit token group names
* @return array
*/
function getTokens(
$string,
$offset = 0,
$defaultTokenName = null,
$groupDelimiters = '\'"',
$groupNameDelimiter = ':')
{
if ($offset >= strlen($string)) {
//echo "offset out of range";
return false;
}
$spaces = " \t\n\r"; // space characters
// add group delimiters to spaces...
$groupSpaces = $spaces . $groupNameDelimiter;
$delimiters = $groupSpaces . $groupDelimiters;
//var_dump($groupSpaces);
$string = ltrim(substr($string, $offset), $groupSpaces);
$token_strings = array();
//echo "String is : " . $string . "\n";
// 1. split all tokens...
while ($offset < strlen($string)) {
$lastOffset = $offset;
$escaped = false;
if (false !== strpos($groupDelimiters, $char = $string[$offset])) {
$groupChar = $char;
} else {
$groupChar = null;
}
if (null !== $groupChar) {
while (($offset < strlen($string)) && (($groupChar !== ($char = $string[++$offset])) || $escaped)) {
//$offset++;
$escaped = ('\\' === $char);
}
$offset++;
//echo "*** Grouped : " . substr($string, $lastOffset, $offset - $lastOffset) . "\n";
} else {
while (($offset < strlen($string)) && ((false === strpos($delimiters, $char = $string[$offset])) || $escaped)) {
$offset++;
$escaped = ('\\' === $char);
}
//echo "*** Non-group : " . substr($string, $lastOffset, $offset - $lastOffset) . "\n";
}
//skip spaces...
while (($offset < strlen($string)) && ((false !== strpos($groupSpaces, $char = $string[$offset])) || $escaped)) {
$offset++;
$escaped = ('\\' === $char);
}
$token_strings[] = substr($string, $lastOffset, $offset - $lastOffset);
//echo "Next token = '" . end($token_strings) . "'\n";
}
$tokens = array();
$tokenName = null;
foreach ($token_strings as $token_str) {
// clean $token_str
$token_str = trim(stripslashes($token_str), $spaces);
$str_value = trim($token_str, $delimiters);
switch (strtolower($str_value)) {
case 'true': $str_value = true; break;
case 'false': $str_value = false; break;
default: break;
}
// is it a token name?
if (':' === substr($token_str, -1, 1)) {
if (!empty($tokenName)) {
$tokens[$tokenName] = '';
}
$tokenName = trim($token_str, $delimiters);
} else {
if (!empty($tokenName)) {
if (isset($tokens[$tokenName])) {
$tokens[$tokenName] = array(
$tokens[$tokenName],
$str_value
);
} else {
$tokens[$tokenName] = $str_value;
}
$tokenName = null;
} elseif (empty($defaultTokenName)) {
$tokens[] = trim($token_str, $delimiters);;
} else {
if (isset($tokens[$defaultTokenName])) {
$tokens[$defaultTokenName] = array(
$tokens[$defaultTokenName],
$str_value
);
} else {
$tokens[$defaultTokenName] = $str_value;
}
}
}
}
if (!empty($tokenName)) {
$tokens[$tokenName] = '';
}
return $tokens;
}
$str = "check1: test "
. "check2:'hello world' "
. 'check3: "foo" '
. "check4: \\\"try this\\\""
. '"buz" '
. 'check1:true';
Пример 14.
$selector = 'div.class#id';
$tagname = strtok($selector,'.#');
echo $tagname.'<br/>';
while($tok = strtok('.#'))
{
echo $tok.'<br/>';
}
Пример 15.
/* subtok(string,chr,pos,len)
*
* chr = chr used to seperate tokens
* pos = starting postion
* len = length, if negative count back from right
*
* subtok('a.b.c.d.e','.',0) = 'a.b.c.d.e'
* subtok('a.b.c.d.e','.',0,2) = 'a.b'
* subtok('a.b.c.d.e','.',2,1) = 'c'
* subtok('a.b.c.d.e','.',2,-1) = 'c.d'
* subtok('a.b.c.d.e','.',-4) = 'b.c.d.e'
* subtok('a.b.c.d.e','.',-4,2) = 'b.c'
* subtok('a.b.c.d.e','.',-4,-1) = 'b.c.d'
*/
function subtok($string,$chr,$pos,$len = NULL) {
return implode($chr,array_slice(explode($chr,$string),$pos,$len));
}
Смотрите также split() и explode().
Все функции строкиОписание на ru2.php.net
Описание на php.ru