PHP's relatively complete solution to the code conversion problem_PHP tutorial

I recently encountered a code conversion problem while writing bbs. After searching for a long time, I finally found a relatively complete solution that can completely restore the original text of the poster.

Posted below for your correction.

System: linux php4 oracle8i
The following is the quoted content:
//--Title, name and other fields are processed into the database (removing leading and trailing spaces)
function trans_string_trim($str) {
$str=trim($str);
$str=eregi_replace("'","''",$str);
$str=stripslashes($str);
return $str;
}
//--Article storage processing, that is, textarea field;
function trans_string($str) {
$str=eregi_replace("'","''",$str);
$str=stripslashes($str);
return $str;
}
//--Displayed in the form from the library; convert with trans in text, in textarea, no conversion is needed, display directly
//--Display on WEB page, filter HTML code; include link address
function trans($string) {
$string=htmlspecialchars($string);
$string=ereg_replace(chr(10),"
",$string);
$string=ereg_replace(chr(32)," ",$string);
return $string;
}
//--Displayed on the WEB page, without filtering HTML code;
function trans_web($string) {
$string=ereg_replace(chr(10),"
",$string);
$string=ereg_replace(chr(32)," ",$string);
return $string;
}
//--Displayed on the WEB page, filtering HTML code and leading and trailing spaces, mainly used to display user nicknames
function trans_trim($string) {
$string=trim($string);
$string=htmlspecialchars($string);
$string=ereg_replace(chr(10),"
",$string);
$string=ereg_replace(chr(32)," ",$string);
return $string;
}
//--displayed in span;
function trans_span($string) {
$string=ereg_replace(chr(10),"n",$string);
$string=ereg_replace(chr(32)," ",$string);
$string=ereg_replace('"',""",$string);
return $string;
}
//--Display cookies on WEB, filter html
function trans_cookie($str) {
$str=trans($str);
$str=stripslashes($str);
$str=eregi_replace("''","'",$str);
return $str;
}
?>


Finally, by the way, if you display a paragraph in the article in span and use substr to get a fixed-length string, remember to add an extra space after the span parameter, otherwise the html code will be messed up when half a Chinese character is intercepted. .