Session life and cross-domain and cross-page --- small doubts and big problems (php)

The session disappears after crossing the page?

Points to note when storing sessions:

1. Stored on the server side in the form of files.
2. Limited life cycle, determined according to different server types.
3. Storage content as serialized string

The content format stored in the session file is as follows:

　We can read some session information from the picture: for example

　There is a session with error and its value is empty; there is also a session with step and its value is 0, and so on.

Now that we know the principle mechanism of session, then, in order for session to be called across pages, several conditions must be met:

1. Turn on session.use_trans_sid, that is, find session.use_trans_sid
in the php configuration file php.ini and then change its value to 1 and remove the comment,

2. Since it is stored in the form of a file, the directory where the session file is saved must always exist and be writable. You can view the session information through phpinfo()
. The directory where session files are saved session.save_path.

Finally, restart php-fmt.

*Attach a screenshot of the session information at the end: