Lynx can be used to access information on the WWW, or to build information systems intended primarily for local access. For example, Lynx has been used to build several Campus Wide Information Systems (CWIS). In addition, Lynx can be used to build systems isolated within a single LAN.
In addition, a summary description of all the Lynx keystroke commands and their key bindings is available by pressing the 'K' key (or the 'k' key if vi-like key movement is not on). [ToC]
lynx filename
lynx /home/my-dir/filename
lynx ~/filename
When executed, Lynx will clear the screen and display as much of the specified file as will fit on the screen. Pressing a down-arrow will bring up the next screen, and pressing an up-arrow will bring up the previous screen. If no file is specified at startup, a default file will be displayed. (The default is configured by the system administrator when the command is installed.)
Lynx will display local files written in the HyperText Markup Language (HTML), if the file's name ends with the characters .html, .htm, .shtml, .htmlx, .html3, or .ht3. HTML is a file format that allows users to create a file that contains (among other things) hypertext links to other files. Several files linked together may be described as a hypertext document. If the filename does not have one of the suffixes mapped by Lynx to HTML, the -force_html command line option can be included to force treatment of the file as hypertext.
When Lynx displays an HTML file, it shows links as "bold face" text, except for one link, which is shown as "highlighted" text. Whether "boldface" or "highlighted" text shows up as reverse video, boldface type, or a color change, etc. depends on the display device being used (and the way in which that device has been configured). Lynx has no control over the exact presentation of links.
The one link displayed as "highlighted" text is the currently "selected" link. Lynx will display the file associated with the selected link when a right-arrow or a Return key is pressed. To select a particular link, press the up-arrow or down-arrow keys until the desired link becomes "highlighted," and then press the right-arrow or Return key to view the linked information. Information included in the HTML file tells Lynx where to find the linked file and what kind of server will provide it (i.e. HTTP, Gopher, etc.).
Lynx renders HTML files and saves the rendition, not the source, for initial display and should you select the link again. If you do select a link again and have reason to desire a new fetch and rendering of the file, use the NOCACHE command, normally mapped to 'x' and 'X', instead of the right-arrow or Return key when positioned on the link. You also can force a new fetch and rendering of the currently displayed document via the RELOAD command, normally mapped to Control-R.
When a binary file is encountered Lynx will ask the user if he/she wishes to download the file or cancel. If the user selects 'D' for download, Lynx will transfer the file into a temporary location and present the user with a list of options. The only default option is Save to disk, which is disabled if Lynx is running in anonymous mode. Any number of additional download methods may be defined in the lynx.cfg file by the system administrator. Programs like kermit, zmodem and FTP are some possible options. [ToC]
+-------+-------+-------+
| TOP | /|\ | Page |
arrow keys | of | | | UP |
| text 7| | 8| 9|
+---------+ +-------+-------+-------+
| SELECT | | | | |
| prev /|\| | <--- | | ---> |
| link | | | 4| 5| 6|
+---------+---------+---------+ +-------+-------+-------+
| BACK | SELECT | DISPLAY | | END | | | Page |
|<-- prev | next | | sel. -->| | of | | | DOWN |
| doc. | link \|/| link | | text 1| \|/ 2| 3|
+---------+---------+---------+ +-------+-------+-------+
There are also a few other keyboard commands to aid in navigation. The
Control and Function keys used for navigation within the current document
are described in Scrolling and Other useful commands. Some
additional commands depend on the fact that Lynx keeps a list of each
link you visited to reach the current document, called the History Page, and a
list of all links visited during the current Lynx session, called the Visited Links Page. The
HISTORY keystroke command, normally mapped to Backspace or
Delete, will show you the History Page of links leading to
your access of the current document. Any of the previous documents shown in
the list may be revisited by selecting them from the history screen. The
VLINKS keystroke command, normally mapped to uppercase 'V', will
show the Visited Links Page, and you similarly can select links in
that list. The MAIN_MENU keystroke command, normally mapped to 'm'
and 'M', will take you back to the starting document unless you
specified the -homepage=URL option at the command line. Also, the
LIST keystroke command, normally mapped to 'l' and L',
will create a compact list of all the links in the current document, and
they can be selected via that list.
The 'i' key presents an index of documents. The default index is usually a document pointing to servers around the world, but the index can be changed by the system administrator or on the command line using the -index=URL switch, and therefore depends on how the Lynx program you are using was configured.
If you choose a link to a server with active access authorization, Lynx will automatically prompt for a username and a password. If you give the correct information, you will then be served the requested information. Lynx will automatically send your username and password to the same server if it is needed again. [ToC]
Additional print options are available for users who are using Lynx from their own accounts (that is, so-called "non-anonymous users"). In particular, the Save to a local file option allows you to save the document into a file on your disk space. Any number of additional print options may also be available as configured by your system administrator.
Some options, such as Save to a local file, involve prompting for an output filename. All output filename entries are saved in a circular buffer, and any previous entries can be retrieved for re-use by pressing the up-arrow or down-arrow keys at the prompt.
Note that if you want exact copies of text files without any expansions of TAB characters to spaces you should use the Download options. [ToC]
Selecting the Print to a local file option from the Print Menu, makes it possible to save the source of the document to disk so that you may have a local copy of the document source, but it is better to Download the source.
NOTE: When saving an HTML document it is important to name the document with a .html extension, if you want to read it with Lynx again later.
Lynx can allow users to edit documents that reside on the local system. To enable editing, documents must be referenced using a "file:" URL or by specifying a plain filename on the command line as in the following two examples:
lynx file://localhost/FULL/PATH/FILENAME
lynx path/filename.html
Some options, such as Save to disk, involve prompting for an output filename. All output filename entries are saved in a circular buffer, and any previous entries can be retrieved for re-use by pressing the up-arrow or down-arrow keys at the prompt. [ToC]
The NOCACHE ('x' or 'X') command can be used in lieu of ACTIVATE (Return or right-arrow) to request an uncached copy and new rendition for the current link, or resubmission of a FORM, if a cache from a previous request or submission exits. The request or submission will include Pragma: no-cache and Cache-Control: no-cache in its headers. Note that FORMs with POST content will be resubmitted regardless of whether the NOCACHE or ACTIVATE command is used (see Lynx and HTML Forms). [ToC]
While viewing a normal document use the '/' command to find a word or phrase within the current document. The search type will depend on the search option setting in the Options Menu. The search options are case sensitive and case insensitive. These searches are entirely local to Lynx.
Some documents are designated index documents by virtue of an ISINDEX element in their HEAD section. These documents can be used to retrieve additional information based on searches using words or phrases submitted to an index server. The Lynx statusline will indicate that you are viewing such a document, and if so, the 's' key will invoke a statusline prompt to enter a query string. The prompt can be specified via a PROMPT attribute in the ISINDEX element. Otherwise, Lynx will use an internally configured prompt. The address for submitting the search can be specified via an HREF or ACTION attribute. Otherwise, Lynx will use the current document's URL and append your query string as a ?searchpart.
All search words or strings which you have entered during a Lynx session are saved in a circular buffer, and can be retrieved for re-use by pressing the up-arrow or down-arrow keys at the prompt for a search word or string. Also, you can use the 'n'ext command to repeat a search with the last-entered search word or phrase, starting from the current position in the document. The word or phrase matches will be highlighted throughout the document, but such highlighting will not persist for new documents, or if the current document is reloaded. The search cycles to the top of the document if the word or phrase is not located below your current position.
Although HTML Forms have largely replaced index
documents for searches via http servers, they are still useful for performing
searches directly via WAIS or Gopher servers in conjunction with the internal
gateways for such servers. For example, an HTML index document can act as a
cover page describing a WAIS database and how to formulate query
strings for searching it, and include an element such as:
for submitting a search of the Biologist's Addresses database directly
to the net.bio.net WAIS server. [ToC]
Options Menu
E)ditor : emacs
D)ISPLAY variable : aixtest.cc.ukans.edu:0.0
mu(L)ti-bookmarks: OFF B)ookmark file: lynx_bookmarks.html
F)TP sort criteria : By Filename
P)ersonal mail address : montulli@netscape.com
S)earching type : CASE INSENSITIVE
preferred document lan(G)uage: en
preferred document c(H)arset : NONE
display (C)haracter set : ISO Latin 1
raw 8-bit or CJK m(O)de : ON show color (&) : OFF
V)I keys: OFF e(M)acs keys: OFF sho(W) dot files: OFF
popups for selec(T) fields : ON show cursor (@) : OFF
K)eypad mode : Numbers act as arrows
li(N)e edit style : Default Binding
l(I)st directory style : Mixed style
U)ser mode : Advanced
user (A)gent : [User-Agent header]
local e(X)ecution links : FOR LOCAL FILES ONLY
An option can be changed by entering the capital letter or character in
parentheses for the option you wish to change (e.g. 'E' for Editor
or '@' for show cursor). For fields where text must be entered,
simply enter the text by typing on the keyboard. The Line Editor can be used to
correct mistakes, and Control-U can be used to erase the whole
line. When you are done entering a change press the Return key
to get back to the Command? prompt.
For fields where you must choose one of two choices, press any key to toggle the choices and press the Return key to finish the change.
For fields where you potentially have more than two choices, popup windows may be evoked which function homologously to those for select fields in HTML Forms. The popup windows will be invoked only if you have popups for select fields set to ON (see below). Otherwise, your cursor will be positioned at the current choice, and you can press any key to cycle through the choices, then press the Return key to finish the change.
When you are done changing options use the 'r' command to return to Lynx or the '>' command to save the options to a .lynxrc file and return to Lynx.
The following table describes the options available on the Options Menu:
By Filename", "By Size",
"By Type", and "By Date".
Once you have decided to send a comment or have selected a mailto: link a new screen will appear showing you to whom you are sending the message. Lynx will ask for your name, your e-mail address, and the subject of the message. If you have filled in the "personal mail address" field in the Options Menu, your e-mail address will be filled in automatically. After entering the above information, if you have an editor defined in the Options Menu and you are not an anonymous user then your specified editor will be spawned for you so that you can enter your message. If you do not have an editor defined or you are an anonymous user, a simple line mode input scheme will allow you to enter your message.
To finish sending the message, exit your spawned editor or, if you are using the simple line mode input scheme, type a '.' (period) on a line by itself. You will be asked a final time whether to send the message. If you press 'y', you will be prompted whether to append your signature file if one was defined in lynx.cfg and is accessible, and then the message will be sent, whereas if you press 'n' the message will be deleted. Entering Control-G in response to any prompts also will cancel the mailing.[ToC]
To save a bookmark to the document you wish to place in the bookmark file press the 'a' key and you will be asked:
Save D)ocument or L)ink to bookmark file or C)ancel? (d,l,c):Answer 'd' to save a link to the document you are currently viewing or 'l' to save the link that is currently selected on the page. Selecting 'c' will cancel without saving anything to your bookmark file.
A bookmark file will be created in conjunction with acting on the 'a'dd command if it does not already exist. Otherwise, the link will be added to the bottom of the pre-existing bookmark file. You must have created a bookmark file via the 'a'dd command before you can view it.
Use the 'v' command to view the list of bookmarks you have saved. While viewing the bookmark list you may select a bookmark as you would any other link.
You can remove a link from the bookmark list by pressing the 'r' key when positioned on that link. You also can use a standard text editor (e.g., via the 'e'dit command while viewing a bookmark file, if an external editor has been defined via the Options menu) to delete or re-order links in the bookmark file, or to modify a link name by editing the content of the Anchor element for the link, but you should not change the format within the line for the link, consisting of an LI element followed by the Anchor element, nor cause the line to become wrapped to a second line. You similarly can change the link destination by editing the double-quoted value for the HREF attribute in the Anchor start tag, but you should not otherwise change the spacing within the start tag, nor add other attributes. You can add a new link while editing by copying an existing line for a link, to ensure the proper format, and then modifying its HREF value and Anchor content, but you should not add any other HTML markup to the bookmark file. If the format and spacing (other than the Anchor content or HREF value) within lines is changed or other HTML markup is added, the 'a'dd and 'r'emove commands may not work properly.
When multi-bookmarks (see Options Menu) is OFF, you will always view or add links to the default bookmark file. When it is STANDARD, a menu of up to 26 bookmark files will be invoked, and you select the bookmark file by entering its letter token. When it is ADVANCED, you will be prompted for the letter token, but can enter '=' to invoke the STANDARD selection menu, or RETURN for the default bookmark file. [ToC]
All jump shortcut entries are saved in a circular buffer, and any previous entries can be retrieved for re-use by pressing the up-arrow or down-arrow keys at the prompt.
Note to System Administrators: Read the lynx.cfg file on how to set up the jump command for your system and how to define shortcut names. [ToC]
C)reate
D)ownload
E)dit
F)ull Menu
M)odify
R)emove
T)ag
U)pload
An HTML Form provides for the use of buttons to perform an action (such as submit), checkboxes, radio buttons or popups to select options from a list, and fields for entering text.
NOTE: If you have a text input field selected you will not have access to most of the Lynx keystroke commands, because they are interpreted by the Line Editor as either text entries or editing commands. Select a button or box when you want to use Lynx keystrokes.
To submit the form press
right-arrow or Return when positioned on the form's
submit button. If you've submitted the form previously during the Lynx
session, have not changed any of the form content, and the METHOD was
GET, Lynx will retrieve from its cache what was returned from the
previous submission. If you wish to resubmit that form to the server with
the same content as previously, use the RESUBMIT command ('x') when
positioned on the submit button. The right-arrow and Return
keys also will invoke a no-cache resubmission if the reply from a form
submission included a META element with a no-cache Pragma or Cache-Control
directive:
or the server sent a "Pragma" or "Cache-Control" MIME header with a
no-cache directive.
You also can use the DOWNLOAD ('d') keystroke command when positioned on a form submit button if you wish to download the server's reply to the submission instead of having Lynx render and display it.
Forms which have POST as the METHOD, or a mailto: URL as the ACTION, are always resubmitted, even if the content has not changed, when you activate the submit button. Lynx normally will not resubmit a form which has POST as the METHOD if the document returned by the form has links which you activated, and then you go back via the PREV_DOC (left-arrow) command or via the History Page. Lynx can be compiled so that it resubmits the form in those cases as well, and the default can be changed via lynx.cfg, and toggled via the -resubmit_posts command line switch.
If the form has one text entry field and no other fields except, possibly, hidden INPUT fields not included in the display, then that field also serves as a submit button, and pressing right-arrow or Return on that field will invoke submission of the form. Be sure to use up-arrow, down-arrow or TAB to move off the text entry field, in such cases, if it is not your intention to submit the form (or to retrieve what was returned from an earlier submission if the content was not changed and the METHOD was GET).
Forms can have multiple submit buttons, if they have been assigned NAMEs in the markup. In such cases, information about which one of the buttons was used to submit the form is included in the form content.
Inlined images can be used as submit buttons in forms. If such buttons are assigned NAMEs in the markup, for graphic clients they can also serve as image maps, and the x,y coordinates of the graphic client's cursor position in the image when it was clicked are included in the form content. Since Lynx cannot inline the image, and the user could not have moved a cursor from the origin for the image, if no alternatives are made available in the markup Lynx sends a 0,0 coordinate pair in the form content. Document authors who use images as submit buttons, but have at least some concern for text clients and sight-challenged Webizens, should include VALUEs for the buttons in such markup. Lynx will then display the string assigned to the VALUE, as it would for a normal submit button. Some document authors incorrectly use an ALT instead of VALUE attribute for this purpose. Lynx "cooperates" by treating ALT as a synonym for VALUE when present in an INPUT tag with TYPE="image". If neither a VALUE nor an ALT attribute is present, Lynx displays "[IMAGE]-Submit" as the string for such buttons. If clickable images is set, the "[IMAGE]" portion of the string is a link for the image, and the "Submit" portion is the button for submitting the form. Otherwise, the entire string is treated as a submit button. If a VALUE or ALT attribute is present and clickable images is set, Lynx prepends "[IMAGE]" as a link for the image, followed by '-' and then the attribute's value as the displayed string for the submit button. Note that earlier versions of Lynx would send a name=value pair instead of a 0,0 coordinate pair if a TYPE="image" submit button was NAME-ed, had a VALUE attribute in the INPUT tag, and was used to submit the form. The script which analyzes the form content thus could be made aware whether the submission was by a user with a graphic client and had image loading turned on, or by a user who did not see the image nor make a conscious choice within it. However, requests that this be included in HTML specifications consistently have fallen on deaf ears, and thus Lynx now "fakes" a 0,0 coordinate pair whether or not a VALUE or ALT attribute is present in the INPUT tag. Ideally, the script which analyzes the submitted content will treat the 0,0 coordinate pair as an indicator that the user did not see the image and make a conscious choice within it.
Forms can have hidden INPUT fields, which are not displayed, but have NAMEs and VALUEs included in the content. These often are used to keep track of information across a series of related form submissions, but have the potential for including information about the user that might be considered to represent an invasion of privacy. NOTE, in this regard, that Lynx has implemented the HTML 3.0 DISABLED attribute for all of its form fields. These can be used to keep track of information across submissions, and to cast it unmodifiable in the current form, but keep the user aware that it will be included in the submission.
Forms most commonly are submitted to http servers with the content encoded as ENCTYPE="application/x-www-form-urlencoded" for analysis by a script, and Lynx treats that as the default if no ENCTYPE is specified in the FORM start tag. However, you can specify a mailto URL as the form's ACTION to have the form content sent, instead, to an email address. In such cases, you may wish to specify ENCTYPE="text/plain" in the form markup, so that the content will not be encoded, but remain readable as plain text.
Lynx also supports ENCTYPE="application/sgml-form-urlencoded" for which all reserved characters in the content will be hex escaped, as with application/x-www-form-urlencoded, but semicolons (';') instead of ampersands ('&') will be used as the separator for name=value pairs in the form content. The use of semicolons is preferred for forms with the GET METHOD, because the GET METHOD causes the encoded form content to be appended as a ?searchpart for the form's ACTION, and if such URLs are used in text/html documents or bookmark files without conversion of the ampersands to SGML character references (& or &), their being followed by form field NAMEs which might correspond to SGML entities could lead to corruption of the intended URL.
NOTE, in this regard, that Lynx converts ampersands to & when creating bookmarks, and thus the bookmark links will not be vulnerable to such corruptions. Also NOTE that Lynx allows you to save links in your bookmark file for documents returned by forms with the GET METHOD, and which thus have the content appended as a ?searchpart, but not if the METHOD was POST, because the content would be lost and the link thus would be invalid.
Lynx supports ENCTYPE="multipart/form-data" for sending form content with name=value pairs encoded as multipart sections with individual MIME headers and boundaries. However, Lynx does not yet support INPUTs with TYPE="file" or TYPE="range" and will set the DISABLED attribute for all of the form's fields if any INPUTs with either of those two TYPEs are present, so that the form can't be submitted. Otherwise, Lynx will submit the form with the multipart ENCTYPE.
A Content-Disposition: file; filename=name.suffix
header can be used by CGI scripts to set the suggested filename offered
by Lynx for 'd'ownload and 'p'rint menu options to save
or mail the body returned by the script following submission of a FORM.
Otherwise, Lynx uses the last symbolic element in the path for the FORM's
ACTION, which is normally the script, itself, or a PATH_INFO field, and
thus might be misleading. This also can be done via a META element in
any document:
[ToC]
Lynx recognizes the TABLE element and all of its associated elements as described in ftp://ds.internic.net/rfc/rfc1942.txt and will process any ID attributes in the start tags for handling as NAME-ed anchors, but does not create actual tables. Instead, it treats the TR start tag as a collapsible BR (line break), and inserts a collapsible space before the content of each TH and TD start tag. This generally makes all of the content of the table readable, preserves most of the intra-cell organization, and makes all of the links in the table accessible, but any information critically dependent on the column and row alignments intended for the table will be missed.
If inherently tabular data must be presented with Lynx, one can use PRE formatted content, or, if the table includes markup not allowed for PRE content, construct the table using HTML Tabs. An example table using TAB elements is included in the test subdirectory of the Lynx distribution. [ToC]
Note that this Users Guide includes TAB markup in a manner which degrades gracefully for WWW browsers which do not support it. Toggle to display of source and search for <tab to examine the use of TAB markup in these documents. [ToC]
Lynx recognizes the Netscape and MicroSoft Explorer FRAME, FRAMESET, and NOFRAMES elements, but is not capable of windowing to create the intended positioning of frames. Instead, Lynx creates labeled links to the frame sources, typically positioned in the upper left corner of the display, and renders the NOFRAMES section. If the document provider has disregard for text clients and sight-challenged Webizens, and thus does not include substantive content in the NOFRAMES section or a link in it to a document suitable for text clients, you can usually guess from the labeling of the frame links which one has the substantive material (if there is any), or you can try each of those links to see if anything worthwhile is returned. [ToC]
Lynx recognizes and processes all of the HTML 3.0 REL attribute tokens in LINK elements for creating a banner, and a number of others which have subsequently been proposed. These banner tokens are Home, ToC, Contents, Index, Glossary, Copyright, Up, Next, Previous, Prev, Help, Search, Top, Origin, Navigator, Child, Disclaimer, Sibling, Parent, Author, Editor, Publisher, Trademark, Meta, URC, Hotlist, Begin, First, End, Last, Pointer, Translation, Definition, Chapter, Documentation, Biblioentry, Bibliography, Bookmark and Banner. Any LINK elements with those tokens as the REL attribute value, and an HREF attribute value in the LINK, will invoke creation of a banner at the top of the first page, with the element's HREF as the link, and the token as the default link name. If a TITLE attribute is included in the LINK, it's value will be used as the link name instead of the default. Bookmark and Banner are intended to be accompanied by a TITLE attribute, which in effect makes the namespace for REL banner tokens infinite.
If the special token Help is used as the REL value and no HREF is included in the LINK, Lynx will use it own HELPFILE URL for that link. For the special token Home without an HREF, Lynx will use the default STARTFILE (i.e., derived from the configuration files or the WWW_HOME environment variable, not the command line startfile if one was used). However, if a -homepage=URL was specified on the command line, it's URL will be used as the HREF. For the special token Index without an HREF, Lynx will use the DEFAULT_INDEX_FILE derived from the configuration files, or if an -index=URL was specified on the command line, it's URL will be used as the HREF.
Lynx does not waste screen real estate maintaining the banner at the top of every page, but the Lynx TOOLBAR keystroke command ('#') will, any time it is pressed, position you on the banner so that any of its links can be activated, and pressing the left-arrow when in the banner will return you to where you were in the current document. The toolbar is indicated by a '#" preceding its first link when present on the screen, that is, when the first page of the document is being displayed. The availability of a toolbar is indicated by a '#' at the top, left-hand corner of the screen when the second or subsequent pages of the document are being displayed.
Lynx also recognizes the HTML 3.0 BANNER container element, and will create a banner based on its content if one has not already been created based on LINK elements. Lynx treats the MicroSoft MARQUEE element as a synonym for BANNER (i.e., presenting it's markup as a static banner, without any horizontal scrolling of its content). Lynx does not prefix the BANNER or MARQUEE content with a '#' because the content need not be only a series of links with brief, descriptive links names, but does add a '#' at the top, left-hand corner of the screen when the content is not being displayed, to indicate it's accessibility via the TOOLBAR keystroke command. [ToC]
i.e., position it at the top of the page. Then, upon reading the footnote, you can return to your previous position in the document by pressing the left-arrow key. The content of an FN element can be any HTML markup that is valid in the BODY of the document. [ToC]
Lynx also supports the TYPE attribute for OL elements, which can have values of 1 for Arabic numbers, I or i for uppercase or lowercase Roman numerals, or A or a for uppercase or lowercase letters, that increment for successive LI elements in the list block. The CONTINUE attribute can be used to continue the ordering from the preceding list block when the nesting depth is changed.
Lynx treats the OL attributes START and SEQNUM as synonyms for specifying the ordering value for the first LI element in the block. The values should be specified as Arabic numbers, but will be displayed as Arabic, Roman, or alphabetical depending on the TYPE for the block. The values can range from -29997 to the system's maximum positive integer for Arabic numbers. For Roman numerals, they can range from 1 (I or i) to 3000 (MMM or mmm.). For alphabetical orders, the values can range from 1 (A or a) to 18278 (ZZZ or zzz). If the CONTINUE attribute is used, you do not need to specify a START or SEQNUM attribute to extend the ordering from a previous block, and you can include a TYPE attribute to change among Arabic, Roman, or alphabetical ordering styles, or their casing, without disrupting the sequence. If you do not include a START, SEQNUM or CONTINUE attribute, the first LI element of each OL block will default to 1, and if you do not include a TYPE attribute, Lynx defaults to Arabic numbers.
For UL blocks without the PLAIN attribute, Lynx uses *, +, o, #, @ and - as bullets to indicate, progressively, the depth within the six nesting levels.
Lynx treats UL, OL, DIR, and MENU blocks as having the COMPACT attribute by default, i.e., single spaces between LH and LI elements within those blocks. For DL blocks, double spacing will be used to separate the DT and DD elements unless the COMPACT attribute has been specified. [ToC]
Lynx renders block quotes with a greater than normal left and right indentation. Lynx does not support italics, and normally substitutes underlining, but does not underline block quotes so as not to obscure any explicit emphasis elements within the quotation. The BLOCKQUOTE or BQ block can include a CREDIT container element, whose content will be rendered as an implied new paragraph with a CREDIT: label at the beginning of its first line.
Lynx respects nested Q start and end tags, and will use ASCII double-quotes (") versus grave accent (`) and apostrophe ('), respectively, for even versus odd depths in the nest.
Any ID attributes in BLOCKQUOTE, BQ or Q elements will be treated as named Anchors. [ToC]
Newer HTML markup provides bases for the client to determine the URLs associated with areas in the image map, and/or for a text client to process alternative markup and allow the user to make choices based on textual information. These have been termed client-side-image-maps.
Lynx recognizes and processes the MAP container element and its AREA elements, and will create a menu of links for the HREF of each AREA when the link created for the IMG element with a USEMAP attribute is activated. The menu uses the ALT attributes of the AREA elements as the link names, or, if the document's author has disregard for text clients and sight-challenged Webizens, and thus did not include ALT attributes, Lynx uses the resolved URLs pointed to by the HREF attributes as the link names. Lynx uses the TITLE attribute of the IMG element, or the TITLE attribute of the MAP, if either was present in the markup, as the title and main header of the menu. Otherwise, it uses the ALT attribute of the IMG element. If neither TITLE nor ALT attributes were present in the markup, Lynx creates and uses a [USEMAP] pseudo-ALT. The MAPs need not be in the same document as the IMG elements. If not in the same document, Lynx will fetch the document which contains the referenced MAP, and locate it based on its NAME or ID attribute. All MAPs encountered in documents during a Lynx session are cached, so that they need not be retrieved repeatedly when referenced in different documents.
If the IMG element also indicates a server-side-image-map via an ISMAP attribute, Lynx normally will create a link for that as well, using an [ISMAP] pseudo-ALT (followed by a hyphen to indicate its association with the client-side-image-map) rather than ignoring it, and will submit a 0,0 coordinate pair if that link is activated. Although, the client-side-image-map may be more useful for a client such as Lynx, because all of the URLs associated with the image map can be accessed, and their nature indicated via ALT attributes, Lynx-friendly sites can map 0,0 such that the server returns a for-text-client document homologous to the content of FIG elements (see below). Inclusion of such a link for submissions to the server can be disabled by default via the configuration file (lynx.cfg), and the default can be toggled via the -ismap command line switch.
Lynx also recognizes the HTML 3.0 FIG and OVERLAY elements, and will handle them as intended for text clients. These are the ideal way to handle client-side-image-maps, because the FIG content provides complete alternative markup, rather than relying on the client to construct a relatively meager list of links with link names based on ALT strings.
The presently experimental OBJECT element encompasses much of the functionality of the FIG element for client-side-image-maps. Lynx will render and display the content of OBJECT elements which have the SHAPES attribute equivalently to its handling of FIG. Lynx also handles OBJECT elements with the USEMAP and/or ISMAP attributes equivalently to its handling of IMG elements with client-side-image-maps and/or server-side-image-maps. [ToC]
Lynx recognizes and processes Refresh directives in META elements, but puts up a labeled link, typically in the upper left corner of the display, indicating the number of seconds intended before a refresh, and the URL for the refresh, instead of making the request automatically after the indicated number of seconds. This allows people using a braille interface any amount of time to examine the current document before activating the link for the next URL. In general, if the number of seconds indicated is short, the timing is not critical and you can activate the link whenever you like. If it is long (e.g., 60 seconds), a server process may be generating new documents or images at that interval, and you would be wasting bandwidth by activating the link at a shorter interval. [ToC]
State Management via cookie exchanges originally was implemented by Netscape, and such cookies are now designated as Version 0. A more elaborate format for cookies, designated as Version 1, is being standardized by the IETF (Internet Engineering Task Force). Lynx supports both Version 0 and Version 1 cookie exchanges. This support can be disabled by default via the SET_COOKIES symbol in the compilation (userdefs.h) and/or run time (lynx.cfg) configuration files, and that default setting can be toggled via the -cookies command line switch.
When cookie support is enabled, Set-Cookie MIME headers received from an http server invoke confirmation prompts with possible replies of 'Y'es or 'N'o for acceptance of the cookie, 'A'lways to accept the cookie and to allow all subsequent cookies from that domain (server's Fully Qualified Domain Name, or site-identifying portion of the FQDN) without further confirmation prompts, or ne'V'er to never allow cookies from that domain to be accepted (silently ignore its Set-Cookie MIME headers). All unexpired cookies are held in a hypothetical Cookie Jar which can be examined via the COOKIE_JAR keystroke command, normally mapped to Ctrl-K, for invoking the Cookie Jar Page. The Cookie Jar, and any 'A'lways or ne'V'er 'allow' settings, do not presently outlast the Lynx session.
A common use of cookies by http servers is simply to track the documents visited by individual users. Though this can be useful to the site's WebMaster for evaluating and improving the organization of links in the various documents of the site, if the user has configured Lynx to include a From MIME header with the user's email address in http requests, or has passed personal information to the server via a form submission, the tracking might be used to draw inferences, possibly incorrect, about that user, and may be considered by some as an invasion of privacy.
An example of worthwhile State Management via cookies is the setting of personal preferences, typically via a form submission to the site, which will then apply to all documents visited at that site.
If you accept cookies when accessing a site, but are given no indication about how they will be used in subsequent requests to that site, nor can infer how they will be used, you can Gobble (delete) the cookies and/or change the 'allow' setting for its domain via the Cookie Jar Page. [ToC]
This distributed approach let providers retain complete control over their information, but it made communication between users and providers somewhat more difficult. Following the lead of Neal Erdwien, of Kansas State University, the Lynx hypertext format was extended to include links for including ownership information with each file. This information made it possible for users running Lynx clients to send comments and suggestions via e-mail to the providers.
This early version of Lynx was also augmented to support hypertext links to programs running on remote systems. It included the ability to open a Telnet connection, as well as the ability to start programs via rexec, inetd, or by direct socket connects. These capabilities were included to allow users to access databases or custom program interfaces.
A subsequent version of Lynx incorporated the World Wide Web libraries to allow access to the full list of WWW servers, along with the option to build hypertext documents in HTML, rather than the native Lynx format. HTML has become far more widely used, and the native format has been phased out. With the addition of the WWW libraries, Lynx became a fully-featured WWW client, limited only by the display capabilities offered in the curses environment.
Lynx was designed by Lou Montulli, Charles Rezac and Michael Grobe of Academic Computing Services at The University of Kansas. Lynx was implemented by Lou Montulli and maintained by Garrett Arch Blythe and Craig Lavender.
Foteos Macrides and members of the lynx-dev list have developed and supported Lynx since release of v2.3 in May 1994. The Lynx2-3FM code set was released as v2.4 in June 1995. The Lynx2-4FM code set was released as v2.5 in May 1996. The Lynx2-5FM code set was released as v2.6 in September 1996. The Lynx2-6FM code set was released as v2.7 in February 1997, and v2.7.1 with bug fixes for v2.7 was released in April 1997.
Lynx has incorporated code from a variety of sources along the way. The earliest versions of Lynx included code from Earl Fogel of Computing Services at the University of Saskatchewan, who implemented HYPERREZ in the Unix environment. Those versions also incorporated libraries from the Unix Gopher clients developed at the University of Minnesota, and the later versions of Lynx rely on the WWW client library code developed by Tim Berners-Lee (and others) and the WWW community.
Information on obtaining the most current version of Lynx is available via Lynx links.
[ToC]