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This program is distributed in the hope that it will be useful, but without any warranty ; without even the implied warranty of merchantability or fitness for a particular purpose . See the GNU General Public License for more details.
Welcome to Links, the most powerful web browser for professional work with WWW. The Links web browser combines ease of use of the user interafcace with crystal clear picture of exactly rendered video output and also with power and reliability of HTTP requester and HTML parser written without compromisses manually in C.
New user interface unique for Links web browser makes work easier and faster for people seriously interested in routine, fast, accurate and secure work with WWW. New functions like asynchronous DNS lookup or possibility of smooth enlarging images on page ease up quick movement in WWW space in an unprecedented way. Orienting in thumbnails on image search engines is made easier using this image enlargement technology. Simple and thorough system of interactive menus allows easy and unambiguous configuration of the browser with maximum possible security for sensitive data.
Links web browser is conceived to fullfill complicated demans of today's low-level IT specialists.
Links web browser posesses easily controllable powerful internal mechanisms for DNS lookup, HTTP requests, HTML parsing, decoding of image data streams, execution of Javascript and rendering of quality videographics. The system ensures very high and accurate graphics power suitable even for demanding applications, like presentation of medical data with high dynamics of grey scale (X-ray images) in projection halls or preview in proffessional photography archives and presentation volumes from primary image data carries in 48-bit colour depth corresponding to use of professional drum scanners. This property is at the same time allowed on common displays or projectors with standard colour depth with only 24 bits per pixel, even under unfavourable gamma conditions in the display chain. All web applications working with image material may be exploited in a way that ensures currently unusual level of quality of graphics output and accomodation to particular user's working environment. Information loss can be prevented now even with high processing speed and exploiting dynamics of wide possibilities of the WWW interface.
User interface in text mode is backward compatible with user control of Lynx web browser, therefore users that have been using this browser until now can withhout problems move on to Links web browser.
Resampling subsystem of Links presents the typeface at unprecedented legibility even at extremely high numbers of lines per screen. Thanks to it the employment of screen area is at it's maximum at physical boundariy of the particular monitor available to the user. Ergonomy of the work and reading reliability is increased. Working comfort is stabilized. Work output is maximized during specialized researches in WWW information space. A technology of adaptive convolution preemphasis of spatial spectrum of text portion of the screen image ensures additional enlargement of these benefits in area of small interline pixel pitches.
On the other hand the used resampling technology brings finer letter contours at high interline pitches, reduction of the necessary amount of font data and unusually flexible possibility of unicode glyph set extension by national alphabet or arbitrary pictorial symbols, independently from source platform of glyph image data. Moreover insertion of a glyph is possible without prior vectorisation directly from physical image carriers directly after performing rasterization on image acquisition device.
The used unique technology "Low-profile footprint in file system" (LPFFS) allows immediate and easy integration of all browser components at the same time into the existing file hierarchy of the operating system. Thanks to the LPFFS technology, the browser presents itself after installation by only a single executable file into which all components necessary for browser runtime are already integrated. Thanks to the LPFFS technology problems during installation and possible uninstallation are prevented. The possibility of immediate realization of conflict-free installation of the browser is fostered in an existing file system while keeping compatibility with the file system hierarchy standard (FHS) even on very large and complicated systems of remote file tree sharing over a network.
Image, graphics and colour elements of HTML pages are processed on a highly standardized level, which ensures maximum reproducibility of the output on various imaging platforms and during presentation of diverse image formats. The video and typesetting subsystems complies to standards RFC 1867, RFC 1942, RFC 1945, RFC 2068, RFC 2109, RFC 959, RFC 1738, RFC 1808, RFC 1288, ITU T.81, CCIR Recommendation 601, JFIF 1.02, ISO DIS 10918-1, RFC 2083, IEC 61966-2-1, ISO 9241.
Links is shipped in a form of source code archive links-2.0.tar.gz . Source texts are freely accessible on web. For the installation we suppose that you have the file links-2.0.tar.gz in current diretory.
For installation and running Links in text mode, the following basic programs are necessary:
For operation in graphics mode the following libraries are necessary in addition:
If libtiff or libjpeg is not installed on your system, the browser will compile without TIFF or JPEG image support, rspectively. LIbrary libpng is necessary for operation of the browser , as internal fonts are stored in PNG format.
The following libraries are optional:
gzip -d links-2.0.tar.gz tar -xvf links-2.0.tar
bzip2 -d links-2.0.tar.bz2 tar -xvf links-2.0.tar
cd links-2.0
./configure --enable-graphics --enable-javascriptIf you want to compile the browser as a text-only version (without graphics support), write only
./configure --enable-javascriptThe configure program should find all necessary libraries on your system. In a rare case it can happen that some libraries are not foundalthough they are installed (for example when you have an atypical installation). In such a case you have no other option than entering the library path for the unfound libraries manually using switches:
If you want to set up configuration script parameters in a more detailed way, using the following command you will learn all the possible parameters:
./configure --helpIf you need to set up special paths to header files and libraries before running the configure script, set up environment variables CFLAGS , CPPFLAGS , LDFLAGS . This is only for advanced users, if you aren't sure, ask your system administrator. Therefore if you want for example look for header files in the path /usr/ext/include and libraries in path /usr/ext/lib , before running the configure script, write for example (in bash ):
export CFLAGS="$CFLAGS -I/usr/ext/include" export CPPFLAGS="$CFLAGS -I/usr/ext/include" export LDFLAGS="$LDFLAGS -L/usr/ext/lib"
make
cp ./links /usr/bin/If you are installing the browser as an user, copy the file links into your home directory, into a directory where you store executable files. For example:
cp ./links ~/bin/
cd .. rm -r links-2.0.tar links-2.0
At this moment the installation is complete. Now it is necessary to perform calibration. If your browser is compiled for text mode only, skip the calibration procedure and start reading directly the chapter about running and control of the program.
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Run
links -g doc/calibration.htmlor possibly write a different path to the file nebo případně napište jinou cestu k souboru calibration.html (where you copied the documentation).
If you are connected to the Interet, you can display the calibration directly from the Internet. Write on the command line:
links -gAfter seeing the welcome dialogue, close it by pressing ENTER , then press the key ESC or click left mouse button on the bar on the top edge of the browser window. Then using the keys left and right move on to "Help" and press ENTER . Possibly click by mouse on "Help". Now using keys up and down select "Calibration" and press ENTER or directly click on "Calibration".
On the screen you should see this picture:
Now proceed exactly step by step according to the instructions on your screen.
In this chapter you can read basic informations about controlling and running the Links browser. In the following chapters you can find a detailed description of individual functions and browser setup.
./linksIf the binary file is in your path, it suffices to type on the commandline:
links
You can enter switches after the links command on the command line. These switches control run of the browser. The switches are written in the form -switch , where "switch" is the name of the switch. The switches are delimited from the program name and from other switches by a space. Behind the switches you can (but do not have to) enter URL of the page you want to fetch, or a path to HTML file on local filesystem (if you want to display a page saved on your local filesystem). Separate the URL by a space, too.
Example:
links www.altavista.com
Some switches moreover demand a value, which you have to write after the switch and again separate from the switch by a space. In the followin table you can read about the most often used switches and their meaning.
\table[|l|l|] \topline Switch &Meaning \cr \midline -g &The browser will run in graphics mode\cr \midline -mode &Serves setting of graphics driver mode\cr &(see running in graphics mode).\cr \midline -driver &Specifies a graphics system that should be used. If\cr &you do not use the switch, graphics system will be autodetected.\cr \midline -help &Prints out a summary of switches and keyboard control.\cr \midline -version &Displays version number of the program.\cr \botline \endtable
To enter the graphics mode you have to use the switch -g . Type on the commandline:
links -g
Links will try to autodetect the graphic systems which you have installed on your computer. If it finds one, it will switch into graphics mode. Graphics systems will be detected in this sequence: pmshell , x , svgalib , atheos . If you want to choose the graphics system manually, use the switch -driver with one of the arguments: pmshell , x nebo svgalib .
For example:
links -g -driver svgalib
If you are using the X-Window system and detection fails, you have to correctly set up the environment variable prostředí DISPLAY to point to your display.
-mode switch serves the purpose to pass parameters to the graphics driver. For SVGAlib system it is used to determine screen resolution. For X-Window system it selected the display.
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Using the -mode switch you set up graphics resolution. To learn all possible resolutions write:
links -g -mode help
Graphics resolution is being delimited in this format:
wherex x
Example of graphics modes:
1024x768x16M 800x600x64K 320x200x16 1280x1024x32K 1024x768x16M32 640x480x256
If you want for example to run Links in graphics resolution 1024$\times$768 and 16 milllions colours, write:
links -g -mode 1024x768x16M
To run the program you need a colour display and minimum colour depth of 4 bits (16 colours) with possibility to set up private palette. Grayscale modes are not supported, as well as so called "StaticColor" modes which do not allow setting up private colour palette. If your display has more colour depths, the browser will choose the greatest one. If you have a display with only paletted mode, the program will create it's own colour paletter, which will be set up on activation of the window and reset back after deactivation.
In the X-Window system the switch -mode sets display on which the output from Links web browser should be displayed. The display is written down in format
In majority of cases the: .
Examples, what the commandline may look like during running under the X-Window system:
links -g -mode delta.ether.net:0.0 links -g -driver x -mode localhost:0.0 links -g -driver x -mode :0.0 links -g -mode micron:1.0
In the first example the output of the browser will be displayed on remote computer delta.ether.net . In the second case you explicitly say that X-Window graphics driver should be used and the output should be displayed on the computer you run the browser on. Third case is equivalent to second one. In the last example the output will be displayed on computer micron in local network, on display number 1.
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Links runs on framebuffer graphics system on Linux operating system. There is a limitation that only systems with linear memory mapping are supported. Another limitation is on the mouse driver, which is implemented using the gpm library, which is the only portable way of implementation. As the gpm library is created for text mode and graphics mode has much higher resolution, the mouse would be too slow. Therefore the mouse pointer doesn't move smoothly but in steps of several pixels. In exceptional cases it is possible that a particular place on the screen will not be possible to click to. For this you can use the keys F5 , F6 , F7 , and F8 for fine movements of the mouse pointer.
This is not a bug of Links, but of the gpm library, which is character oriented. As there is not any other option how to read mouse on framebuffer, this is the only known way, how to read the mouse. If you do not like this solution, please write to the authors of gpm to add graphics support into gpm .
If you have administrator rights, it is possible to change source texts of gpm for the mouse pointer to move smoothly, and then recompile gpm . Patch gpm with patch included with Links, which you find in the directory with the program, it is named PATCH-gpm-1.20.0-smooth-cursor . The patch has been created for source codes of gpm version 1.20.0. It will probably work for other versions of gpm too.
Links After first run, directory .links will be created. It will be created in your home directory determined from system variable \$HOME (if it doesn't exist, then in the directory where binary file links is stored). This created directory will be used for storing configuration files, bookmarks, history and more system information.
First we will clarify some terms that will later occur in the text:
The mouse in basic version has two or three buttons on it. The buttons are called left , right , and middle . The left button is the one closest to the left edge of the mouse, the right one is the one closest to the right edge of the mouse. The middle button is present only on three-button mouses and resides between left and right button.
The mouse is controlled this way: using palm of hand (right-handed people will use right palm and left-handed people left palm) the mouse is moved around over the underlying surface. Buttons are pressed by finger (best by pointing finger, middle finger and ring finger).
Some mouses have instead of middle button a scrolling wheel (we will talk about scrolling later). If you press the wheel, it works as the middle button. Rolling the wheel you scroll up and down. Mouses with two wheels occur too --- instead of middle button and instead of the right button. The wheel present in place of middle button (1. wheel) is used for vertical scrolling. The wheel on the right button (2. wheel) is used for scrolling in horizontal direction.
Sometimes the term cursor also denotes a highlighted rectangle that can be moved over the text. For example in the menu the cursor highlights the currently selected entry.
The most natural vision of this is that we have a page of text (the text ve view) and a rectangular magnifying glass through which we look at the text (the magnifying glass substitutes the screen). And because the magnifying glass doesn't cover the whole page, then we have to shift it -- scroll. We say for example that we scroll right which in our case means that we move the magnifying glass rightwards.
If we want to scrool the text for example down, we move the mouse on the rectangle on vertical scrollbar, hold the left mouse button and move the mouse down. This way the rectangle on scrollbar moves down and the text scrolls down. If we want to stop scrolling, then we simply stop holding the left button.
If we are using mouse with scrolling wheel, turning the wheel we scroll in current frame.
protocol://server-address/path-to-document-on-server
Using URL, HTTP document (web page) can be addressed. Also FTP directories can be addressed as well as files on local disk. Examples of URL:
http://www.google.com/ www.praha-mesto.cz http://artax.karlin.mff.cuni.cz/~mikulas/links/index.cgi ftp://ftp.gnu.org/ /usr/doc/HOWTO/Vim-HOWTO.txt
After running web browser window is displayed. If you entered URL on commandline, the requested page will be displayed directly. Otherwise a gray area will be displayed. On the bottom endge of the window so called status line is visible, where informations about passage of the connection are displayed. Link address is also displayed here (if you point to a link with the cursor) as well as image title and similar things. In the upper left corner there is an arrow that servers for movement into history.
Text entry dialogs are often used within Links\. For example entering URL, during search, and so on. Therefore we will describe here how these dialogs are to be controlled.
The dialogue contains a field for entering text and buttons OK and Zrušit . Text can be normally written into the text field, keys BACKSPACE a DELETE delete text, keys left and right move cursor around the text. Keys CTRL +x erases the whole line and puts it into the clipboard (OS/2 only). Keys CTRL +v insert clipboard contents (again only on OS/2). CTRL +u erases text from the cursor to the beginning of the line.
Using up/down cursor keys history of previously entered values can be browsed. CTRL +w key combination activates text autocompletion function. If you want to enter a text that you have already previously entered, just several leading characters have to be typed and by pressing this key combination a possible continuation will be filled in or a dialogue with possibilities is presented if there are more thann one possibility.
By clicking on the key OK you confirm the entered text. By clicking on Cancel you cancel entering the text.
Now we are going to describe how to move around the page, what is being displayed on the page, how to click on links and how to scroll the displayed page.
Links has a capability to create so called virtual consoles on graphics systems where new browser windows cannot be created. It's about that after running the browser you have a possibility of making up to 10 virtual consoles which correspond to browser windows on a windowing system. You can switch between virtual consoles using key combinations ALT +1 , ALT +2 to ALT +0 . If you create a new browser window (for example by function "New window"), a new virtual console will be allocated with lowest number (after running the browser you are therefore on virtual console number 1) and required page will be displayed on it. If you close window, the corresponding virtual console will disappear and the remaining consoles will remain as they are - they won't be renumbered as one could think.
This technology allows users to parallel viewing of more pages even on systems where windows can't be created.
As is known, HTML pages can contain frames. It is possible to switch between individual frames in text mode by key TAB and in graphics mode clicking inside the frame.
Scrolling a page is simple too. In graphics mode you can scroll using scrollbar situated on the right side of the frame. You can also scroll by cursor arrows. Keys cudl{PAGE UP} and PAGE DOWN serve purpose of shifting to previous or next page of the document. You can scroll by one page also by pressing space bar. Keys HOME and END move to beginning or end of document, respectively. If you have a mouse with wheel, you can scroll in vertical direction in graphics mode using this wheel. If you have a mouse with two wheels, the first wheel (usually in place of middle button) serves vertical scrolling and second wheel (usually in right button) serves horizontal scroll.
You can scroll at any time using the middle button: hold the middle button down and move the mouse as if you wanted to grab and slide paper page by hand. This way shifting in all direction works --- both horizontally and vertically. So if you hold middle button and move mouse to the right, the view is being moved towards left edge of the whole page. By mouse you therefore move to the other side than by scrollbar.
The same way you can move the page using right mouse button but only when you do not hit an image, link, form element and similar. If you hit it with right button, a menu of actions appears that can be performed with the image, link, or element.
In text mode the keys PAGE UP , PAGE DOWN , HOME , END and space work analogically. As cursor arrows are used for movement over the links, the page is to be moved to the left and right by keys $[$ and $]$ , in up/down direction by keys INSERT and DELETE (or by CTRL +p a CTRL +n .
If a page contains more frames, the described routine works in the current frame.
Links are selected in graphics mode simply by clicking the link. In text mode you have to first select the link by up/down arrows. The current (selected) link is denoted by inverted background. If you want to follow the link, press right arrow key or the key ENTER . Links are written in blue, unless the page defines a different colour for the links.
After clicking on a link, Links first starts to look up a server (sends a DNS query), after that it starts establishing a connection with the remote server. After the connection is established, a request for page is transmitted and then only waiting for the reply is performed. The whole course of the communication is displayed in status line on the bottom of the screen. As soon as the whole page is downloaded, "OK" will be displayed. If the page hasn't been yet downloaded, you have a possibility to terminate establishment of the connection by the "back" function (by key Z or in text mode by left arrow key, also by clicking the left arrow in top left corner).
Adter loading the page, the status line show informations about links, images and other elements of page. If you move over a link, address of link target is displayed (you can easily determine if something is a link by this method). If you move over an image, it's title (alt attribute or URL of the image in case it doesn't have an alt) is displayed. After moving over a form element (text area, checkbox, radio button etc.) an information about that particular form element is displayed (for example it's name, value, address where the form will be sent to, ...).
If javascript is running on some page, it can also write into the status line. In this case the status line doesn't show these informations but the text that javascript set.
What a status line at bottom edge of the screen looks like.
During loading the page currently not yet loaded or decoded images are displayed as a frame with size of the image (as specified in HTML). After downloading and decoding the image, the image will be displayed instead of this frame. If an error occurs due to which the image cannot be downloaded, the image is damaged or it can't be displayed for another reason, a broken frame will be shown instead of the image. A frame has dimensions of the image (if dimensions are known). In case they are not known, the frame has basic dimensions 32$\times$32 pixels.
Upper side of the image shows what a broken image looks like. In the lower part you see how a yet undownloaded image is shown.
Links partially doesn't support certain HTML tags, which can occur on a page, but as some can contain important information, Links displays such tags as links. Actually they are tags:
On some page you can encounter a link Refresh linking to a different page. "Refresh" is redirection to a different page, which is being performed automatically in some cases. Links doesn't perform redirection automatically, because it's utmost uncomfortable for the users to get before the page with the redirection, because after pressing "Go back" she gets on the page with the redirect and this will automatically redirect him forward again. To avoid this, redirection is displayed as "Refresh" in Links. After clicking the link, redirection to the target page will be performed.
If some characters occurs at web page which Links doesn't have in it's font, a character "blotch" will be displayed instead of them. If there are too many blotches in the page and you think that the page should display correctly, try in "HTML options" menu in "View" to change the value of "Default codepage". It is possible that the server doesn't send information about code page and you just have a different encoding set as default. It is also possible that the server is sending a wrong information about code page of the document. For this case you can in the same menu tick the entry "Ignore charset info sent by the server".
Instead of missing character, a blotch symbol is displayed:
If foreground and background colours have too similar luminances, then the foreground colour will be selected as much contrasting to the background colour as possible. This function is builtin in Links to increase legibility of text on pages that have unsuitably set colours in a way that it makes the text difficult to read for the user.
The whole Links program is being controlled using interactive menus, the control is therefore very easy and intuitive. All functions can be summoned from the main menu, some can be on top of this summoned by so called hot key. You can invoke the main menu by pressing the key ESC or by clicking the mouse on bar on the top edge of the window. You can close the menu by repeated pressing of ESC or by clicking under the bar on top edge of the window. You select individual entried in menu either by direct clicking of mouse on the required entry, or by cursor keys --- in main menu left and right, in pulldown menus by up and down keys. ENTER or space bar serve for selection of required entry.
Some entried of the menu have one character of the name highlighted (by inverse background). If you press this letter in menu, a direct choice of this entry will be performed, which is usually faster than moving on the entry with cursor or mouse.
To the right of some entries a so called hot key can be mentioned. If you press this hot key anywhere in the browser, the corresponding function will be directly called, which is again faster than looking for the function in menu. You don't have to remember hot keys --- all available functions can be reached through the menu.
Dialogues can be controlled very similarly as menus: by up and down arrows you select individual entries of the dialogue, by spacebar you activate the selected entry (a button is pressed, a tickbox is ticked and similar). Or you can of course use mouse. DIalogue is canceled by ESC key. This means that it will be closed and all changes (entered text, ticked up tick box and similar), which you did, will be forgotten. On the other by key ENTER the dialogue will close and all changes will be accepter.
Dialogue windows can also contain fields for entering text. If you want to enter text into such a field, first you have to activate the field (either by clicking it with mouse or selecting by cursor keys) --- there will a cursor appear in the field. After this you can normally insert text, numbers and similar. Using keys left / right you move around the text, by keys BACKSPACE and DELETE you delete the text. By keys up / down you leave the text field and therefore end editation.
Now we are going to show all functions of the browser in detail, as they are mentioned in the menu.
In the menu File find function working with URL: change of URL, history, bookmarks, then functions for downloading document, system information, operating system commandline and ending the browser.
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During first invocation of this function, this page will be requested again from the network. If a PROXY cache is between you and the Internet, it can hapen that PROXY cache replies immediately from it's own cache and will not download the document from network. Therefore second and further "Reload" requests the page again from the network, but this time forces downloading from the network even with PROXY cache. During second and subsequent "Reload", a "Pragma: no-cache" is actually present in the HTTP request.
Bookmarks allow you easy storage of a pointer to an interesting page. They are being used the same way as bookmarks in a book.
The bookmark consist of a name (bookmark label) and URL. Bookmarks are ordered into directories, which makes orientation easier and increases comfort. After invoking function "Bookmarks", a window with bookmark manager appears on the screen. In the top part of the window there is a list of bookmarks and directories (or their names). At bottom border of the window you can then find buttons which allow managing the bookmarks.
There is a list in the upper part of the window. Cursor keys, keys PAGE UP , PAGE DOWN , HOME and END move the bar. You can select entry in this list like in a menu. Selected entry is again denoted by a bar with inverse background. Left and right arrow keys select button (by the lower edge of the window), by pressing enter you activate the button. By clicking left mouse button you select an entry. Scrolling is performed by holding middle button and dragging mouse up and down. Scrolling can be also done by a scrollbar at the right edge of the window.
Left from every entry there is a graphics symbol that depicts if it is a bookmark, open directory, or closed directory. Minus sign in a square means closed directory, plus sign in a square means open directory and horizontal line means a bookmark. Vertical lines show which directory the bookmark belongs to. By clicking directory symbol or moving on to directory and pressing space bar you can open or close a directory. By key adresář a stisknutím mezerníku adresář otevřete / zavřete. Klávesou + you open a directory, by key - you close it.
Now we will describe individual actions that can be performed using the buttons. Buttons work with an entry (bookmark or directory) with cursor. We will call this entry current entry.
Entries in the list can also be moved. This function is performed by button Move . First it is necessary to mark the entry you want to move. An entry can be marked by key INSERT or * (these keys unmark a marked entry and unmark marked one), or by clicking right mouse button on corresponding entry. The marked entry has an asterisk before it's name (in text mode) or a little square (in graphics mode). By button Unselect all you can unselect all entries. When a directory is closed, all entries inside the directory are automatically unselected.
Now, if you have all entries that you want to move marked, go with cursor bar over the entry behind that you want to move the selected entried and click button Move . Selected entries will be move behind current entry, if current entry is an open directory, the entries will be placed into that directory. Moved entries will be in the same order as they were before the movement (therefore the sequence of selected entried will not change). Directories will be moved including their contents.
Bookmarks are stored into file bookmarks.html in directory .links in your home directory. Format of the file is compatible with format that browser of Netscape company use, therefore it's possible to have common bookmarks for browsers Links and Netscape. Path and name of the file, where bookmarks will be stored, can be selected in menu "Setup-> Miscellaneous Options". In the same menu you can also set up encoding of the bookmarks file. If you change the file or encoding of the bookmarks, the changes that you have made in bookmarks, will be automatically stored and a file with new bookmarks will be loaded.
Changes in bookmarks (for example addition, deletion and similar) are automatically stored at exit of the browser. Therefore it's not necessary to explicitly save the bookmarks with some menu function. After first execution of the browser (actually when the bookmark file doesn't exist yet), a basic bookmark file will be created for you. This file will contain home page of Links and calibration procedure.
In svgalib and framebuffer graphics environments instead of opening a new window, lowest free virtual console number in Links will be assigned to a newly created virtual console. The page will be displayed on this console. Virtual console are being switched using keys ALT +0 to ALT +9 . If you close a console, console will disappear and the remaining consoles will remain as they are (they will not be renumbered).
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Menu View contains function regarding displayed page: search in document, switching between formatted and nonformatted document, informations about the document and HTML settings.
During search letter case is being ignored. This however doesn't hold with letters with accents. Accented letters will be sought for in exact way. Therefore don't forget this behaviour during entering the text.
For explanation we'll show couple of examples:
In this menu, various settings regarding page display can be done. The menu contains these entries:
Link menu contains actions that can be done with currently selected link. For example download, display image, follow link and similar. In graphics mode, this menu is displayed after clicking right button on the link.
Contains an overview of files that are being currently downloaded in background. After clicking one of the items a window with detailed information and possibility to interrupt is presented. In the following picture you can see the menu with selection of individual files being downloaded.
The following information is displayed in the window displayed for particular file:
This way a window with detailed information about particular file looks like:
Clicking the button Background you put the download on background again. Button Abort you abort download. By Abort and delete file you abort download and delete partially downloaded file. Attention, the browser won't ask you if you press the buttons - it will immediately abort. Therefore if you press this button in error, the download will be aborted and you will have to download the file again.
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In this menu you can find all global settings of the browser, for example language setting, character set setting (applicable for text terminal only), network, terminal, javascript, cache, and similar. If you change some setting, then don't forget to click the entry Save options , which saves the change into configuration file. If you don't save the changes, the changes will be forgotten after closing down the program and the old values will be used when the browser is started up next time.
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This presents a menu, where you can select language of the menus. Up and down arrows select language, enter confirms the selection, the key ESC cancels the selection menu.
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The "Vide Settings" entry is available only in the graphics mode. After clicking on it, the vide setting window will appear. It's possible to set momnitor gamma of your monitor, turn on / off image and text dithering, turn on aspect ration correction or an optimization for LCD displays.
The dialogue contains fields for entering gamma correction value for individual colour channels (red, green, blue) and then user gamma for correction of ambient lighting. The description of correct gamma setting follows.
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Setting the gamma correction
First it is necessary for you to correctly set up contrast and brightness
of your monitor according to the following instructions:
Table of gamma corrections for various lighting intensities: \table[|l|r|r|] \topline Ambient lighting intensity &Illuminance $[$lux$]$ &Gamma \cr \midline Projection room&0&1.33\cr \midline Darkened room&4&1.22\cr \midline Dark room&16&1.11\cr \midline Usual illumination of a computer workplace&64&1.00\cr \midline Somewhat brighter computer workplace&256&0.94\cr \midline Brightly lit workplace&1024&0.88\cr \botline \endtable
Now, when your monitor is correctly set, you can set up the gamma correction:
The fields Aspect ratio are for aspect ratio correction in graphics modes with non-square pixels. The usual ration (now we are talking about monitors with cathode ray tube) is 4:3. 4:3 corresponds to 800x600, 1024x768, 640x480 etc. With these resolutions, the pixels on the screen are square. With other resolutions (e. g. 640x400, 320x200) the pixels are elongated in one direction. So if you try to draw a square on the screen, you will see an oblong. Aspect ratio is to correct this problem.
Fill in the field Aspect ratio with ratio of monitor pixel width divided by monitor pixel height. So if the image is narrow and tall, insert a number greater than 1, if wide and low, set a number lower than 1.
In typical cases the default setting of 1 should be sufficient, because the graphics driver automatically determines the resolution and calculates a correction coefficient according to this, for a screen with 4:3 side ratio. If this is not enough (for example you have an atypical monitor), the coefficient has to be set manually.
By ticking up the field Aspect correction on you turn on the aspect correction. If the aspect correction if off, the pixels on screen are mapped 1:1 to pixels on the CRT/LCD.
Once more a summary: turn on the aspect ration correction, leave the value at 1 and try on the calibration picture, if the circle is displayed as a circle. If not then correct the shape by chaging the value. Increase if the picture is too tall and narrow, decrease if low and wide.
Furthemore you can set in this menu for what output device the picture should be optimized. Tick up one of the following possibilities:
You can find the sequence of the pixels on your LCD in technical parameters or you can look with a magnifying glass or try out the best sharpness of little letters.
The LCD display correction is necessary because on an LCD display the picture elements are side to side so the three separate images are shifted by 1/3 pixel. On CRT this is adjusted so the images exactly fit over each other.
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In this dialogue you set parameters of network access.
HTTP and FTP proxy cache: if your network is behind a proxy server, it is necessary to set the address of your HTTP or FTP proxy server. If you don't know it, ask your network administrator. The address is inserted either as address or address:port . For example:
proxy.cache.intra proxy.cache.intra:10000If an HTTP proxy cache is configured, all HTTP requests will be set to the configured proxy on given address and port. Similar for FTP.
Furthermore various parameters of network connections can be set:
The FTP options button invokes a dialogue where you can enter a password for anonymous access to FTP servers. Some FTP servers require a password for anonymous access. The password is usually e-mail address of the one who is accessing the anonymous FTP server.
The button HTTP options invokes a dialogue for setting the properties of HTTP connections. In this dialogue you can set:
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Furthermore you can set the referer to one of the following possibilities. HTTP rerefer means that the browser sends an information to the server telling from which page you got to the currently loaded page. However this is not secure as you may wish to keep this information undisclosed. The following are your options:
You have an option to fill in a text into the Fake User-Agent field. This text will be sent to the user as user-agent. User-agent is an information about your browser and operating system. By default a true information about your operating system and Links browser is being sent. If you insert any text into this field, then this text will be sent instead and the server will never know your real operating system and browser. If you leave the field empty, the true user-agent will be reported.
\penalty -10000
In this dialogue you can set up various parameters of the javascript interpreter.
In the dialog window "Miscellaneous options" in graphics mode you can set the menu letter size. Furhter you can set the file where bookmarks are stored and character encoding of the bookmarks.
Menu font size determines how big letter should be in the menu. The size is counted in screen pixels.
In this dialogue you can set colours of various parts of the menu: foreground , background , scroll-bar , scroll-bar knob , and scroll-bar frame . All colours are entered in the form of hexadecimal triplet of bytes R,G,B (red, green, blue). That is a group of six characters 0-9 , a-F , for each components two characters. For example 00ff00 is bright green, 000000 is black, 444400 is dark yellow, a700a7 is light violet, ffffff is white and so on.
Bookmarks file is a file into which the bookmarks will be saved (see the chapter about bookmarks). By default a file bookmarks.html is used in directory .links in your home directory. In this dialogue you can change the bookmark file, for example when you want to share bookmarks with other browsers. When you are changing the bookmarks file the changes you have already done will be saved into the old one and the new file will be automatically loaded.
After clicking on Bookmarks encoding you will have an option to select from encoding in which the bookmarks file will be stored. Similar to change of the filename, a change in the encoding causes the pending changes to be saved into the old file in old encoding and a new file in new encoding will be loaded.
If it is not possible to determine keyboard input encodingin graphics mode from the environment variables, this menu contains one more entry. The entry is a button marked Keyboard encoding . After pressing this button you will be presented with a choice of encoding in which your keyboard is sending the characters. This setting is different for each graphics driver. For example you can have a different encoding for SVGAlib than for X-Window system. Encoding selection is always related to that graphics driver you are currently running under.
In this dialogue you can set the cache size for document cache (in kilobytes) and number of formatted documents that can be stored in the cache. Maximum number of documents in the cache is 256.
In this doalogue you can set programs for mail and telnet. They are used for links like "mailto:", "telnet:", and "tn3270:". The dialogue contains three text fields: program for mail, program for telnet and program for tn3270. Write commands which should be executed into these fields, the character "\ will be replaced by the address (in case of mail program) or name of machine and port (in case of telnet).
These two functions allow you to set execution of external programs for unknown file types. Each file received over the network has so called MIME type. The MIME type is a text string consisting from two parts separated by a slash. The part before slash is so called main type which says if it's text, image, audio etc. The part after slash is defining the file format. For example when the main type if audio then it can say it's MP3 format. In the table below you can find an overview of some of the widely used MIME types.
\table[|l|l|l|l|] \topline Format &Description &MIME type \hfil&Extension \cr \midline GIF&image format&image/gif&gif\cr \midline JPG&image format&image/jpg&jpg\cr &&image/jpeg&\cr \midline TIFF&image format&image/tiff&tiff\cr \midline PNG&image format&image/png&png\cr \midline PCX&image format&image/pcx&pcx\cr \midline BMP&image format&image/bmp&bmp\cr \midline AVI&video format&video/x-msvideo&avi\cr \midline MP3&audio format&audio/mpeg&mp3\cr \midline OGG&audio format&application/x-ogg&ogg\cr \midline RealAudio&audio format&audio/x-pn-realaudio&ra\cr \midline PostScript&format for document transmission&application/postscript&ps\cr \midline PDF&format for document transmission&application/pdf&pdf\cr &&application/x-pdf&\cr \midline DVI&format for document transmission&application/x-dvi&dvi\cr \midline DOC&format for document transmission&application/x-doc&doc\cr \botline \endtable
The Links browser can display only text and images, however it allows setting external programs to be executed for MIME types it doesn't know, for example for autio files. For this there are these two functions. In the "associations" function you can set an external program and MIME types, for which this program should be executed. In the "extensions" function you can set assign MIME types to file extensions for case the MIME type is not known or not possible to get from the server and the MIME type is to be derived from filename extension.
Both associations and extensions are managed in a window very similar to the "Bookmark manager" window. After invoking the "Associations" or "File extensions" function, a window labeled "Associations manager" or "Extension manager" appears.
The work with Associations manager and Extensions manager is the same, therefore we first describe the elements common for control of both parts and at the end we describe windows for editation and addition which differ between associations and extensions.
Like in the bookmark manager, there is a list of extensions or associations in the top window. There are buttons Add , Delete , Edit , Move , Deselect all and Close at the bottom. Each extension or association shows a label and a mime-type after a colon which belongs to the association or extension.
It is possible to select an entry in the upper part of the window similar to a menu. The selected entry is again highlighted by a bar with inverse background. It is possible to move the bar with cursor keys and PAGE UP , PAGE DOWN , HOME , and END keys. With left and right cursor keys we select the button (in the lower part of the window), pressing ENTER activates the button. By clicking the left mouse button we select an entry. You can scroll by holding the middle mouse button and moving the mouse up and down. It is also possible to scroll with the scrollbar at the right part of the window.
Now we are going to talk about individual actions that can be performed using the buttons. The buttons always have effect on the entry (extension or association) which is signified by the cursor. We will call this entry current entry.
It is also possible to move the entries in the list. And this is what the button Move is for. First it is necessary to mark the entries we want to move. An entry can be marked by the INSERT key or * . These keys unmark a marked entry and mark an unmarked one. It is also possible to mark entries by clicking the right mouse button on the entry. A marked entry has an asterisk in front (in text mode) or a square (graphics mode). If you press the Deselect all button, all entries will be unmarked.
Now, when you have all entries you want to move marked, go with the cursor bar over the entry behind which you want to move the entries. Then press the Move button. The marked entries will be moved just after the current entry. The marked entries will be in the same sequence they were before the move (that means the relative sequence of the marked entried is unchanged).
Associations
The dialogue for editing and adding new associations looks like this:
Here are example of MIME type settings:
Label: ZGV Content-Type(s): image/gif,image/jpg,image/pcx,image/bmp,image/png Program: zgv % Label: Acrobat Content-Type(s): application/pdf,application/x-pdf Program: acroread % Label: MP3 Content-Type(s): audio/mpeg Program: mpg123 -2 -v -b 500 %
Of course you can set more programs for a single MIME type (for example multiple PDF viewers). If you set more program, a dialog will be presented before executing the external program, where you can select which of the programs should be executed.
File extensions
This function allows certain file extensions to be bound together with a
concrete MIME type. The extension is used in the case when it is not
possible to determine the MIME type from a server. The type is then determined
from the filename extension.
Editation and addition of a new extension invokes a dialogue into which
you enter a list of extensions (without the dot) separated by commas, and
a MIME type on which these extensions should be mapped. So for example:
Extension(s): gif Type: image/gif Extension(s): pdf Type: application/pdf Extension(s): dvi Type: application/x-dvi Extension(s): jpg Type: image/jpeg
If you are running the browser for the first time, extensions for basic file types (images, graphics formats, documents, music files, animations etc.) will be automatically created.
Saves the settings into the configuration file. If you change some setting and don't save the settings later, then the change will be forgotten when the browser is exited. Therefore do not forget to save the setting if you change something and want it to be kept for the next execution of the browser.
The Help menu contains a help for the program: a list of keyboard functions, on-line manual and program licence information. The Keys entry displays a window with a list of hotkeys. After pressing the User's manual entry an online manual will be displayed (works only if you are connected to the Internet network). If you are connected to the Internet you can also visit the Links homepage by clicking the Home page . By clicking Calibration you get on the browser calibration procedure that needs to be performed after the first execution of the browser. This function works again only when you are connected to the Internet.
links -g -driver x -mode hammer-5.forge.cz:0.0
\penalty-10000
URL entry line is utterly impractical because the user has to laboriously try to hit it with the mouse. Pressing one key more (to invoke the URL entry dialogue) is much more practical and faster. The dialogue takes screen space during entering URL, otherwise not.
Copyright (C) 1989, 1991 Free Software Foundation, Inc.\\59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
We protect your rights with two steps:
Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations.
Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and modification follow.
0) This License applies to any program or other work which contains a notice placed by the copyright holder saying it may be distributed under the terms of this General Public License. The "Program", below, refers to any such program or work, and a "work based on the Program" means either the Program or any derivative work under copyright law: that is to say, a work containing the Program or a portion of it, either verbatim or with modifications and/or translated into another language. (Hereinafter, translation is included without limitation in the term "modification".) Each licensee is addressed as "you".
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Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation.
If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found.
Copyright (C) This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) year name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details. The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker., 1 April 1989 Ty Coon, President of Vice
This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License.
In addition, as a special exception, the copyright holders give permission to link the code of portions of this program with the OpenSSL library under certain conditions as described in each individual source file, and distribute linked combinations including the two. You must obey the GNU General Public License in all respects for all of the code used other than OpenSSL. If you modify file(s) with this exception, you may extend this exception to your version of the file(s), but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version. If you delete this exception statement from all source files in the program, then also delete it here.