Problems with preg_replace and ? (question mark) - what to do? - php

Question

I have made this line of code to make the words, that is searced for, enhanced.
$tekst = preg_replace("/($searchstr)/i", '<span style="color: 8fb842; font-weight: bold;">$1</span>', $tekst);
But my problem is, that when I make $searchstr = '?'; it is setting between every letter in the $tekst string.
The whole script is:
/////////////////////////////////
// Set variables and arrays
/////////////////////////////////
$arr_sim = array();
if( !empty($_GET['search']) )
{
$text=strtolower($_GET['search']);
$code_entities_replace = array(' ','--','"','!','#','#','$','%','^','&','*','(',')','_','+','{','}','|',':','"','<','>','?','[',']','\\',';',"'",',','.','/','~','`','=', 'Æ', 'æ', 'æ', 'ø', 'Ø', 'ø', 'å', 'å', 'Å');
$code_entities_match = array('-','--','','_quot_','_s_','_s-a_','_sq_','procent','_tria_','_and_','_star_','_par-st_','_par-end_','_us_','_plus_','_tub-st_','_tub-end_','_line_','_col_','_anf_','_lt_','_st_','_qm_','_sqpar-s_','_sqpar-e_','_backsla2_', '_semcol_','_1anf_','_comma_','_punc_','_slash_','_nearequ_', '_msql-anf_', '_equal_', 'ae', 'ae', 'ae', 'oe', 'oe', 'oe', 'aa', 'aa', 'aa');
$text = str_replace($code_entities_match, $code_entities_replace, $text);
$searchstr = $text;
$search_str = $showpages->escape_str($text);
$showpages->_table = 'pages';
$showpages->_where = " tekst LIKE '%". $search_str . "%' AND language_id = '" . $_SESSION['lang_id']. "'";
$showpages->_orderby = 'id';
$showpages->_order = 'desc';
$f = $showpages->search();
while ( $row = mysql_fetch_array($f) )
{
$arr_text = explode(" ",$row['tekst']);
$percent = 0;
$words = count($arr_text);
foreach( $arr_text as $k => $v )
{
similar_text($search_str, $v, $p);
$percent += $p;
}
$percent = $percent / $words;
$arr_sim[] = array('percent' => $percent, 'id' => $row['id']);
}
}
/////////////////////////////////
// Set some variables
/////////////////////////////////
$arr_len = count($arr_sim);
if( !empty($_GET['offset']) )
$offset = $showpages->escape_str($_GET['offset']);
else
$offset = 0;
if( $arr_len >= 15 )
{
$limit = 15;
} else {
$limit = $arr_len;
}
$start = $offset+$limit;
rsort($arr_sim); // Sort the array to make the script show in the right order.
/////////////////////////////////
///////////////////
// Show content
////////////////////
if( $arr_len > 0 )
// check if the search is performed and any hits were found.
{
for( $i = $offset; $i < $start; $i++)
{
// $arr_sim[$i]['id']
$showpages->_table = 'pages';
$showpages->_id = $arr_sim[$i]['id'];
$showpages->_orderby = 'id';
$showpages->_order = 'desc';
$z = $showpages->search();
$r = $showpages->fetch_array( $z );
$tekst = strip_tags($r['tekst'], "<p><a>");
$str_pos = strpos($tekst, $searchstr);
if( $str_pos > 50 ){
$start_str = '...';
if(strlen($tekst) > 200)
{
$end_str = '...';
}
$tekst = substr($tekst, $str_pos-50, 200);
} else {
$start_str = '';
if(strlen($tekst) > 200)
{
$end_str = '...';
}
$tekst = substr($tekst, 0, 200);
}
$tekst = preg_replace("/($searchstr)/i", '<span style="color: 8fb842; font-weight: bold;">$1</span>', $tekst);
$dataa .= '<style type="text/css">.search-fr { margin-bottom: 15px; } .search-fr a {padding: 0; margin: 0 0 5px 0; font-weight: bold; font-size: 14px;} .search-fr p { padding: 0; margin: 0;}</style>';
$dataa .= '<div class="search-fr">';
$dataa .= '' . $r['emne'] . ' - Matcher din søgning <b>'. round($arr_sim[$i]['percent']).'%</b><br />';
$dataa .= $start_str.$tekst.$end_str;
$dataa .= '</div>';
}
} else {
$dataa .= 'Der er ikke fundet nogle sider, der matcher din søgning. Prøv igen.';
}

Answer 1

You can run the preg_quote() function on $searchstr which will escape any metacharacters before the string is used as your pattern.
For example:
$tekst = preg_replace('/'.preg_quote($searchstr, '/').'/i', '<span style="color: 8fb842; font-weight: bold;">$1</span>', $tekst);