Krishna
Tateneni

    tateneni@pluto.njcc.com

Jost
Schenck

    jost@schenck.de

2002-10-16
3.1
KDE
KControl
cookie

## Cookies

Cookies are a mechanism used by web sites to store and retrieve information using your browser. For example, a web site may allow you to customize the content and layout of the pages you see, so that your choices are persistent across different visits to that web site.

The web site is able to remember your preferences by storing a cookie on your computer. Then, on future visits, the web site retrieves the information stored in the cookie to format the content of the site according to your previously specified preferences.

Thus, cookies play a very useful role in web browsing. Unfortunately, web sites often store and retrieve information in cookies without your explicit knowledge or consent. Some of this information may be quite useful to the web site owners, for example, by allowing them to collect summary statistics on the number of visits different areas of the web sites get, or to customize banner advertising.

The cookies module of the &kcontrol; allows you to set policies for the use of cookies when you are browsing the web with the &konqueror; web browser.

Note that the policies that you set using this control module will not apply to other web browsers such as &Netscape;.

### Policy

Using the Policy tab, you can configure the &kde; applications will handle cookies. You can do this by specifying a general cookie policy as well as special cookie policies for certain domains or hosts.

The top of the policy tab has a checkbox labeled Enable cookies. If you leave this unchecked, cookies will be completely disabled. However, this may make browsing rather inconvenient, especially as some web sites require the use of browsers with cookies enabled.

You will probably want to enable cookies, and then set specific policies on how you want them to be handled.

The first group of options create settings that apply to all cookies.

Only accept cookies from originating server

  Some pages try to set cookies from servers other than the one you are seeing the HTML page from. For example, they show you advertisements, and the advertisements are from another computer, often one that belongs to a large advertising group. These advertisements may try to set a cookie, which would allow them to track the pages you view across multiple websites.

  Disabling this option, will mean only cookies that come from the same web server as you are explicitly connecting to will be accepted.

Automatically accept session cookies

  An increasingly common use for cookies is not to track your movements across many visits to a website, but to just follow what you do during one single visit. Session cookies are saved as long as you are looking at the site, and deleted when you leave it.

  Websites can use this information for various things, most commonly it's a convenience so that you don't have to keep logging in to view pages. For example, on a webmail site, without some kind of session ID, you would have to give your password again for each email you want to read. There are other ways to achieve this, but cookies are simple and very common.

  Enabling this option means that session cookies are always accepted, even if you don't accept any other kind, and even if you choose to reject cookies from a particular site, session cookies from that site will be accepted.

Treat all cookies as session cookies

  If this option is enabled, all cookies are treated as session cookies. That is, they are not kept when you leave the website.

  The definition of leave the website is vague. Some cookies may hang around for a little while after you are no longer viewing any pages on a particular website. This is normal.

The section for Default Policy sets some further options that are mutually exclusive — you can choose only one of these options as the default, but you are free to set a different option for any specific web server.

Ask for confirmation before accepting cookies

  If this option is selected, you will be asked for confirmation every time a cookie is stored or retrieved. You can selectively accept or reject each cookie. The confirmation dialog will also allow you to set a domain specific policy, if you do not want to confirm each cookie for that domain.

Accept all cookies by default

  If this option is selected, all cookies will be accepted without asking for confirmation.

Reject all cookies by default

  If this option is selected, all cookies will be rejected without asking for confirmation.

In addition to the default policy for handling of cookies, which you can set by selecting one of the three options described above, you can also set policies for specific host domains using the controls in the Domain Specific group.

The Ask, Accept, or Reject policy can be applied to a specific domain by clicking on the New... button, which brings up a dialog. In this dialog, you can type the name of the domain (with a leading dot), then select the policy you want to apply to this domain. Note that entries may also get added while you are browsing, if the default policy is to ask for confirmation, and you choose a general policy for a specific host (for example, by selecting Reject all cookies from this domain when asked to confirm a cookie.)

You can also select a specific host domain from the list, and click the Change button to choose a different policy for that domain than the one shown in the list.

To delete a domain specific policy, choose a domain from the list, and then click the Delete button. The default policy will apply to domains which have been deleted from the list.

### Management

In the Management tab you can browse and selectively delete cookies that have been set in the past.

In the upper part of this dialog you can see a list of domains, displayed as a tree. Click on the little + next to a domain to see all cookies that have been set for this particular target domain. If you select one of these cookies, you'll notice that its contents will show up in the frame Cookie Details below.

By clicking the Delete button you can now delete the selected cookie. Click Delete All to delete all cookies stored.

Choose Reload List to reload the list from your hard disk. You might want to do this if you have had the module open and are testing websites, or have made many changes in the module itself.

### Section Author

This section written by:

Krishna Tateneni tateneni@pluto.njcc.com.

Jost Schenck jost@schenck.de.