What are the common functions of PHP

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PHP common function 1. Generate a random string function

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 $hash; } PHP常用函数2.截取一定长度的字符串 注：该函数对gb2312使用有效 function wordscut($string, $length ,$sss=0) { if(strlen($string) >

$length) {if ($sss) {$length=$length-3; $addstr=@#... @ #;} for ($I = 0; $I

< $length; $i++) { if(ord($string[$i]) >

{$wordscut. = $string [$I]. $string [$I + 1]; $iTunes;} else {$wordscut. = $string [$I];}} return $wordscut.$addstr;} return $string;}

PHP common function 3. Get the client ip address

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)

}

PHP common function 4. Create the appropriate folder

Function createdir ($dir=@#@#) {if (! is_dir ($dir)) {$temp = explode (@ # / @ #, $dir); $cur_dir = @ # @ #; for