Implementing the SESSION function in PHP3 (1)

SESSION函数库：session.inc.php3
if (!isset($__session_inc__)){
$__sessi
//require("cookie.inc.php3");
# -------------------------------------------------------------------  
# Session Management v1.0 21.6.1998  
# (c) Wild Karl Heinz   
#  
# This Include handle Session based variable handling  
#  
# Please feel free and use it. If you make it more functional  
# it would be nice to send me a copy.  
#  
# Don't forget - Mysql_connect !  
#  
# The database structure  
# Table structure for table 'session'  
#  
# CREATE TABLE session (  
# id int(11) DEFAULT '0' NOT NULL auto_increment,  
# sid varchar(20) DEFAULT '' NOT NULL,  
# val blob,  
# times timestamp(14),  
# PRIMARY KEY (id),  
# KEY sid (sid),  
# UNIQUE sid_2 (sid)  
# );  
#  
# You'll miss here a cron job to delete the old sessions from db  
# -------------------------------------------------------------------  
// 请注意上面被注释掉的CREATE TABLE语句，
// 你需要在你所使用的数据库上执行这条语句，
// 表名也可以不是session，那么就需要设置下面的$sess_table变量了。
// 此处你需要设置库名，和表名。
// 不过一般建议就使用session作为表名
$sess_db = 'dbname';  
$sess_table = 'session';  
# ----------------------------------------------------  
# Session_CheckID - 检查、设置并返回 Session-ID  
# 参数......: cookie保存时间(以分钟计)
# 也可不设置表示这个 cookie 只在当前session 有效
# 这其实就象ASP中SESSION的时效一样。
# 返回值....: 一个唯一的Session-ID （作为cookie存储）
# ----------------------------------------------------  
function Session_CheckID( $min )  
{
global $sess_sid;  
if( !$sess_sid ) {  
$sess_sid = uniqid( SC ); //取得一个唯一的随机数
/*
if( $min > 0 ) {  
SetCookie("sess_sid", $sess_sid, time()+($min*60), "/", "", 0 );  
}  
else {  
SetCookie("sess_sid", $sess_sid, "", "/", "", 0 );  
}  
上面是原先的代码，会出错。所以另外用了一个更好的函数。
函数库：cookie.inc.php3
*/
jssetcookie("sess_sid",$sess_sid,$min);
return( false );  
}  
else {  
return( true );  
}  
}  
# ----------------------------------------------------------  
# str2arr - 将字符串转换成session数组
# 参数.....: string
# 返回值...: 全局数组（其实就是session)  
#本函数用途：将字符串转换成session数组
#如"session[username]=yourid&session[userpass]=12345"
#将会被转换成下面的数组
# session[username]="yourid"
# session[userpass]="12345"
#请注意函数split(),each(),list(),eval()的用法。
#------------------------------------------------ ----------
function str2arr( $ts )
{
global $session;
$vals = split( "&", $ts );
while( list($key,$val) = each($vals) ) {
list( $name, $wert ) = split( "=", $val );
if( $val ) eval( "$$name = "$wert";" );
}
}
# ----------------------------------------------- ------------
# session_read() - Get data from the SESSION table and convert it into a session array
# Parameters...: None
# Return value.... ..: If the data is read, return true, otherwise return false
#Note...: The str2arr() function is used
# -------------- -----------------------------------------------
function session_read()
{
# Hash array to keep session-variables
global $session;
global $sess_sid, $sess_db, $sess_table, $sess_error;
$sel = "Select val from $sess_table where sid = '$sess_sid'";
$ res = mysql_db_query( $sess_db, $sel );
if( mysql_numrows( $res ) ) {
$val = mysql_result( $res, 0, "val" );
str2arr( $val );
mysql_free_result( $res ) ;
return( true );
}
else {
return( false );
$sess_error = mysql_error();
}
}
# ------------------ ------------------------------------
# Split_Array() - Convert session array into string
# Parameters...: Array
# Return value...: String converted from array
#
# Thanks to Rasmus (this person seems to be the inventor of PHP)
# Note: Convert the session array into a string
#For example, session[username]="yourid"
# session[userpass]="12345"
# will be converted into "session[username]=yourid&session[userpass]=12345"
# At the same time, this function takes into account the situation that an element of the array is also data
#This function is designed as a recursive function
# -------------------------- ----------------------------------
function Split_Array( $arr, $a = "", $b = "", $ c = "" )
{
while( list( $key, $val ) = each( $arr ) ) {
if( is_array( $val ) ) {
$ts .= Split_Array( $arr[ $key ],
( strlen( $a ) ? $a : $key ),
( strlen( $b ) ? $b : ( strlen( $a ) ? $key : "" ) ),
( strlen( $c ) ? $ c : ( strlen( $b ) ? $key : "" ) ) );
}
else {
$ts .= "session";
$ts .= $a ? "[$a]" : "";
$ts .= $b ? "[$b]" : "";
$ts .= $c ? "[$c]" : "";
$ts .= "[$key]=$val&" ;
}
}
return( $ts );
}
# ---------------------------------- ------------------
# session_write - Convert the session array into a string and store it in the session table
# Parameters.: None
# Return value...: If Returns true if the deposit is normal, otherwise returns false
# --------------------------------------------- ------------
function session_write()
{
# Hash array to keep session-variables
global $session;
global $sess_sid, $sess_db, $sess_table;
global $sess_error;
# if you like to delete a session-cookie
# you must check it before writting the session
# array
if( !$sess_sid ) { session_checkid( 0 ); }
$ts = Split_Array( $session );
if( $ts > "" ) { $ts = substr( $ts, 0, strlen( $ts ) - 1 ); }
$res = mysql_db_query( $sess_db, "Select * from session where sid = '$sess_s'" );
if( mysql_numrows( $res ) == 0 ) {
$sel = "Insert into $sess_table ( id, sid, val, times ) ";
$sel .= "values( 0, '$sess_sid', '$ts', NULL )";
}
else {
$sel = "Update $sess_table set val = '$ts', ";
$sel .= "times = NULL where sid = '$sess_sid'";
}
if( !mysql_db_query( $sess_db, $sel ) ) {
$sess_error = mysql_error();
return( false );
}
else { return( true ); }
}
#---------------------------------------------
# session_del - Clear all current sessions
# and delete records related to the current session in the session table
# Parameters....: a random session id
# Return value...: None
# ------ ---------------------------------------
function session_del()
{
global $session , $sess_db, $sess_table, $sess_sid;
$sel = "Delete from $sess_table where sid = '$sess_sid'";
if( !mysql_db_query( $sess_db, $sel ) ) {
$sess_error = mysql_error();
}
$sess_sid = '';
}
}
?>
Original author: Unknown

The above has introduced the function of implementing SESSION in PHP3 (1), including aspects of it. I hope it will be helpful to friends who are interested in PHP tutorials.