Once you log on to csdn, the user name and password will be recorded. When you frequently refresh the web page, you do not need to log on frequently. All of this is due to Cookie.
The cookie file is only a pure text file, with the line break (ASCII = 10) as the separator, the format is as follows:
Cnt_uid_www
Fa565c5abe27b0eb1f0497
Csdn.net/
1536
560450176
29956594
2009325664
29943116
*
Where
1st name of the behavior cookie;
Row 3 is the cookie value;
Row 3 is the address of the site to which the cookie belongs;
The fifth row is a tag value;
5th low behavior timeout (Cardinal/DWORD );
6th high behavior timeout time;
7th low level of behavior creation time;
8th the creation time of a behavior is high;
The fixed row 9th is *, indicating the end of a section.
A file may contain multiple sections, which can be recycled in the preceding format.
We can also use programs to write cookies. When you open a webpage, the webpage can be automatically identified, although such practical applications are not very common.
Internetsetcookie (L "csdn.net/", l "cnt_uid_www", l "fa565c5abe27b0eb1f0497; expires = SAT, 10-jul-2010 00:00:00 GMT ");
As shown above, "expires = SAT, 10-jul-2010 00:00:00 GMT" specifies the cookie validity period.