如果条件，正则表达式在PHP preg_match中踢出HTML textarea输入

Question

I am at a loss on why my PHP code, the preg_match, is not accepting input from an HTML textarea input when it has parentheses or returns:

Here is the relevant PHP:

/* Check for Ingredient Description */
if (preg_match ('%^\s*[A-Za-z0-9\,\.\' \-\"\(\)]{30,2048}$%', stripslashes(trim($_POST['ingredient_descrip'])))) 
{
   $idscr = escape_data($_POST['ingredient_descrip']);
} 
else 
{
   $idscr = FALSE;
   echo '<p><font color="red" size="+1">
      Please enter an ingredient description!</font></p>';
}

The custom function escape_data is as follows:

$dbc = mysql_connect (DBHOST, DBUSER, DBPW)
function escape_data ($data) 
{   
if (function_exists('mysql_real_escape_string')) 
{
    global $dbc; 
    // Need the connection.
    $data = mysql_real_escape_string (trim($data), $dbc);
    $data = strip_tags($data);
} 
else 
{
    $data = mysql_escape_string (trim($data));
    $data = strip_tags($data);
}
// Return the escaped value.    
return $data;
} 

Here is the relevant HTML that calls for the textarea input:

<form action="ingredient_form.php" method="post" enctype="multi-part/form-data">
<fieldset>

<p><b>Ingredient Description:</b></p> 
    <p><textarea cols="100" rows="20" name="ingredient_descrip"></textarea><?php if (isset($_POST['ingredient_descrip'])) echo $_POST['ingredient_descrip']; ?></p>


</fieldset>
<div align="center"><input type="submit" name="submit" value="Submit Proposed Ingredient Profile" /></div>
<input type="hidden" name="submitted" value="TRUE" />

I have tried removing the preg_match and just accepting the textarea input, then using preg_replace function to regain formatting and test with the following code:

if ($_POST['ingredient_descrip']) 
{
$idscr = stripslashes(trim($_POST['ingredient_descrip']));
echo "<p>" .$idscr. "</p>";
$idscr = escape_data($idscr);
echo "<p>" .$idscr. "</p>";
$idscrp = preg_replace("/[
]+/", "<br />", $idscr);

echo "<p>" .stripslashes($idscrp). "</p>";
}                

The preg_replace doesn't seem to be doing its job either. I put this into the textarea for testing purposes:

This is a (test)
Why isn't it working?
but

My echo results come back as:

This is a (test) Why isn't it working? but

This is a (test) 
Why isn\'t it working? 
but

This is a (test) rnWhy isn't it working? rnbut

The preg_replace should be substituting the with a break and then the stripslashes should get rid of the remainin escape characters. What am I missing?

Answer 1

Use nl2br() to replace new lines with <br /> tags, instead of trying to reinvent the wheel with preg_replace().

That said, your preg_replace() call works for me:

$str = <<<STR
foo
bar
baz
STR;

var_dump($str);
$str = preg_replace("/[
]+/", "<br />", $str);
var_dump($str);

Output:

string(11) "foo
bar
baz"
string(21) "foo<br />bar<br />baz"