Session function of php4 (2)

Session_decode and session_encode are vague:

Bool session_decode (string data );
Session_decode () decodes the session data in data, setting variables
Stored in the session.

Bool session_encode (void );
Session_encode () returns a string with the contents of the current
Sessionencoded.

There seems to be no relevant example in php manual. In the literal sense, decode refers to the user's string
After the data is parsed, set it to the session. The encode is to "package" the session data and return it.
To the user. In this case, the encode may play a greater role, and the user registers data to the session.
In the future, we should use encode to extract data, but the content returned by encode still needs to be processed,
For example:
Session_register ("val1 ");
$ Val1 = "abcde"
Session_register ("val2 ");
$ Val1 = 1234
Session_register ("val3 ");
$ Val1 = 123.45

The returned result of session_encode is:

Val1: s: 5: "ABC"; val2: I: 1234; val3: d: 123.45;

Obviously, 's' is string, 'I' and 'D' are numbers, and the length of the 'S' type variable needs to be long.
If your session id is aaeebbcfd4455ec2c0d5cb590f8fab74, then this string is actually
The file/tmp/aaeebbcfd4455ec2c0d5cb590f8fab74 exists.
Now you need to process this string and analyze the session data you want. It's strange that php4
I didn't provide a convenient interface for parsing the register variable... or I didn't find it.
Write one by yourself...
Session_data_init: extracts all "packaged" session_data
Session_data_get get data based on the variable name
Usage:
$ Data = session_data_init ();
$ Result = session_data_get ($ data, "val1 ");
The val1 data can be retrieved.

<?
/*
* Get all date registered in the session
*/
Function session_data_init (){
$ SessionData = session_encode ();
Return $ sessionData;
}
?>

<?
/*
* Extract one variable from enconded session data
*/
Function session_data_get ($ data, $ name ){
$ MatchStr = $ name. "| ";
$ MatchStart = strpos ($ data, $ matchStr );
If ($ matchStart = 0 ){
If (strlen ($ data) <strlen ($ matchStr) return "";
$ TmpStr = substr ($ data, 0, strlen ($ matchStr ));
If (strcmp ($ tmpStr, $ matchStr )! = 0) return "";
}

$ TypeStart = $ matchStart + strlen ($ matchStr );
$ DataType = substr ($ data, $ typeStart, 1 );

If (strcmp ($ dataType, "s") = 0) {/* string */
$ LenStart = $ typeStart + 2;
$ LenEnd = strpos ($ data, ":", $ lenStart)-1;
$ LenLen = $ lenEnd-$ lenStart + 1;
$ StrLen = substr ($ data, $ lenStart, $ lenLen );

$ StrStart = $ lenEnd + 3;
$ StrResult = substr ($ data, $ strStart, $ strLen );
Return $ strResult;
} Else if (strcmp ($ dataType, "I") = 0 |
Strcmp ($ dataType, "d") = 0) {/* number */
$ NumStart = $ typeStart + 2;
$ NumEnd = strpos ($ data, ";", $ numStart)-1;
$ NumLen = numEnd-numStart + 1;
$ NumResult = substr ($ data, $ numStart, $ numLen );
Return $ numResult;
} Else {
Return "";
}
}
?>