Recognized Content Types

There are three disjunct types of content which are recognized by HTMLstrip while parsing:

HTML Tag (tag)

This is just a single HTML tag, i.e. a string beginning with a opening angle bracket directly followed by an identifier, optionally followed by attributes and ending with a closing angle bracket.

Preformatted (pre)

This is any contents enclosed in one of the following container tags:

  1. <nostrip>
  2. <pre>
  3. <xmp>
    

The non-HTML-3.2-conforming "<nostrip>" tag is special here: It acts like "<pre>" as a protection container for HTMLstrip but is also stripped from the output. Use this as a pseudo-block which just preserves its body for the HTMLstrip processing but itself is removed from the output.

Plain Text (txt)

This is anything not falling into one of the two other categories, i.e any content both outside of preformatted areas and outside of HTML tags.

Supported Stripping Levels

The amount of stripping can be controlled by a optimization level, specified via option -O (see below). Higher levels also include all of the lower levels. The following stripping is done on each level:

Level 0:

No real stripping, just removing the sharp/comment-lines ("#...") [txt,tag]. Such lines are a standard feature of WML, so this is always done unless --nosharp was given.

Level 1:

Minimal stripping: Same as level 0 plus stripping of blank and empty lines [txt].

Level 2:

Good stripping: Same as level 1 plus compression of multiple whitespaces (more then one in sequence) to single whitespaces [txt,tag] and stripping of trailing whitespaces at the of of a line [txt,tag,pre].

This level is the default because while providing good optimization the HTML markup is not destroyed and remains human readable.

Level 3:

Best stripping: Same as level 2 plus stripping of leading whitespaces on a line [txt]. This can also be recommended when you still want to make sure that the HTML markup is not destroyed in any case. But the resulting code is a little bit ugly because of the removed whitespaces.

Level 4:

Expert stripping: Same as level 3 plus stripping of HTML comment lines (``"<!-- ... -->"'') and crunching of HTML tag endsi [tag]. BE CAREFUL HERE: Comment lines are widely used for hiding some Java or JavaScript code for browsers which are not capable of ignoring those stuff. When using this optimization level make sure all your JavaScript code is hided correctly by adding HTMLstrip's "<nostrip>" tags around the comment delimiters.

Level 5:

Crazy stripping: Same as level 4 plus wrapping lines around to fit in an 80 column view window. This saves some newlines but both leads to really unreadable markup code and opens the window for a lot of problems when this code is used to layout the page in a browser. Use with care. This is only experimental!

Additionally the following global strippings are done:

"^\n":

A leading newline is always stripped.

"<suck>":

The "<suck>" tag just absorbs itself and all whitespaces around it. This is like the backslash for line-continuation, but is done in Pass 8, i.e. really at the end. Use this inside HTML tag definitions to absorb whitespaces, for instance around %body when used inside "<table>" structures which at some point are newline-sensitive in Netscape Navigator.