[PHP] practical function 2_PHP tutorial-php Tutorial

[PHP] function 2. 1. copy the code to generate a random string function: functionrandom ($ length) {$ hash ##; $ chars # signature ##; $ maxstrl 1. Generate a random string function

The code is as follows:

Function random ($ length ){
$ Hash = @#@#;
$ Chars =@# ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789abcdefghijklmnopqrstuvwxyz @#;
$ Max = strlen ($ chars)-1;
Mt_srand (double) microtime () * 1000000 );
For ($ I = 0; $ I <$ length; $ I ++ ){
$ Hash. = $ chars [mt_rand (0, $ max)];
}
Return $ hash;
}

2. truncate a string of a certain length (this function is valid for GB2312)

The code is as follows:

Function Wordscut ($ string, $ length, $ sss = 0 ){
If (strlen ($ string)> $ length ){
If ($ sss ){
$ Length = $ length-3;
$ Addstr = @#...@#;
}
For ($ I = 0; $ I <$ length; $ I ++ ){
If (ord ($ string [$ I])> 127 ){
$ Wordscut. = $ string [$ I]. $ string [$ I + 1];
$ I ++;
} Else {
$ Wordscut. = $ string [$ I];
}
}
Return $ wordscut. $ addstr;
}
Return $ string;
}

3. obtain the client IP address

The code is as follows:

Function GetIP (){
If (getenv ("HTTP_CLIENT_IP") & strcasecmp (getenv ("HTTP_CLIENT_IP"), "unknown "))
$ Ip = getenv ("HTTP_CLIENT_IP ");
Else if (getenv ("HTTP_X_FORWARDED_FOR") & strcasecmp (getenv ("HTTP_X_FORWARDED_FOR"), "unknown "))
$ Ip = getenv ("HTTP_X_FORWARDED_FOR ");
Else if (getenv ("REMOTE_ADDR") & strcasecmp (getenv ("REMOTE_ADDR"), "unknown "))
$ Ip = getenv ("REMOTE_ADDR ");
Else if (isset ($ _ SERVER [@ # REMOTE_ADDR @ #]) & $ _ SERVER [@ # REMOTE_ADDR @ #] & strcasecmp ($ _ SERVER [@ # REMOTE_ADDR @ #], "unknown "))
$ Ip = $ _ SERVER [@ # REMOTE_ADDR @ #];
Else
$ Ip = "unknown ";

Return ($ ip );
}

4. determine the email address

The code is as follows:

Function checkEmail ($ inAddress)
{
Return (ereg ("^ ([a-zA-Z0-9 _-]) + @ ([a-zA-Z0-9 _-]) + (\. [a-zA-Z0-9 _-]) +", $ inAddress ));
}

5. paging (two functions are used together)

The code is as follows:

Function getpage ($ SQL, $ page_size = 20)
{
Global $ page, $ totalpage, $ sums; // out param
$ Page = $ _ GET ["page"];
// $ Eachpage = $ page_size;
$ Pagesql = strstr ($ SQL, "from ");
$ Pagesql = "select count (*) as ids". $ pagesql;
$ Result = mysql_query ($ pagesql );
If ($ rs = mysql_fetch_array ($ result) $ sums = $ rs [0];
$ Totalpage = ceil ($ sums/$ page_size );
If ((! $ Page) ($ page <1) $ page = 1;
$ Startpos = ($ page-1) * $ page_size;
$ SQL. = "limit $ startpos, $ page_size ";
Return $ SQL;
}
Function showbar ($ string = "")
{
Global $ page, $ totalpage;
$ Out = "total". $ Totalpage ."Page ";
$ LinkNum = 4;
$ Start = ($ page-round ($ linkNum/2)> 0? ($ Page-round ($ linkNum/2): "1 ";
$ End = ($ page + round ($ linkNum/2) <$ totalpage? ($ Page + round ($ linkNum/2): $ totalpage;
$ Prestart = $ start-1;
$ Nextend = $ end + 1;
If ($ page <> 1)
$ Out. = "first page ";
If ($ start> 1)
$ Out. = "... <";

For ($ t = $ start; $ t <= $ end; $ t ++)
{
$ Out. = ($ page = $ t )? "[". $ T."]":" $ T ";
}
If ($ end <$ totalpage)
$ Out. = "> ..";
If ($ page <> $ totalpage)
$ Out. = "Last page ";
Return $ out;
}

6. get the ID of the newly inserted data

The code is as follows:

Mysql_insert_id ();
?>

The compile code is as follows: functionrandom ($ length) {$ hash =##; $ chars =# comment #; $ max = strl...