The remaining Table of Contents 1. COMMAND-LINE Options 2. FIELDS / Columns a. DESCRIPTIONS of Fields b. SELECTING and ORDERING Columns 3. INTERACTIVE Commands a. GLOBAL Commands b. SUMMARY Area Commands c. TASK Area Commands d. COLOR Mapping 4. ALTERNATE-DISPLAY Mode a. WINDOWS Overview b. COMMANDS for Windows 5. FILES a. SYSTEM Configuration File b. PERSONAL Configuration File 6. STUPID TRICKS Sampler a. Kernel Magic b. Bouncing Windows c. The Big Bird Window 7. BUGS, 8. HISTORY Former top, 9. AUTHOR, 10. SEE ALSO

When operating , the two most important keys are help ('h' or '?') and quit ('q') key. Alternatively, you could simply use the traditional interrupt key ('^C') when you're done.

When you start for the first time, you'll be presented with the traditional screen elements: 1) Summary Area; 2) Message/Prompt Line; 3) Columns Header; 4) Task Area. There will, however, be some differences when compared to the former top.

Highlighting

Summary_Area: There is no highlighting for load/uptime and only values are highlighted for other elements.

Task_Area: Tasks running (or ready to run) will be highlighted, and bold is only one way of emphasizing such processes.

Content/Labels

Summary_Area: The program name is shown, perhaps a symlink or alias. The Cpu(s) state label hints at other possibilities. The memory stats use a lower case 'k'.

Columns_Header: Will show a new field and some changed labels. More new fields will be found as you customize your .

the width of 's display will be limited to 512 positions. Displaying all fields requires a minimum of 160 characters. The remaining width could be used for the 'Command' column.

The following startup defaults assume no , thus no user customizations. Even so, items shown with an could be overridden through the command-line.

Global_defaults 'A' - Alt display Off (full-screen) * 'd' - Delay time 3.0 seconds 'I' - Irix mode On (no, 'solaris' smp) * 'p' - PID monitoring Off * 's' - Secure mode Off (unsecured) 'B' - Bold disable Off Summary_Area_defaults 'l' - Load Avg/Uptime On (thus program name) 't' - Task/Cpu states On (1+1 lines, see '1') 'm' - Mem/Swap usage On (2 lines worth) '1' - Single Cpu On (thus 1 line if smp) Task_Area_defaults 'b' - Bold hilite On (not 'reverse') * 'c' - Command line Off (name, not cmdline) * 'i' - Idle tasks On (show all tasks) 'R' - Reverse sort On (pids high-to-low) * 'S' - Cumulative time Off (no, dead children) 'x' - Column hilite Off (no, sort field) 'y' - Row hilite On (yes, running tasks) 'z' - color/mono Off (no, colors)

Listed below are 's available fields. They are always associated with the letter shown, regardless of the position you may have established for them with the 'o' (Order fields) .

Any field is selectable as the sort field, and you control whether they are sorted high-to-low or low-to-high. For additional information on sort provisions 3c. TASK Area Commands.

a: PID Process Id

The task's unique process ID, which periodically wraps, though never restarting at zero.

b: PPID Parent Process Pid

The process ID of a task's parent.

c: RUSER Real User Name

The real user name of the task's owner.

d: UID User Id

The effective user ID of the task's owner.

e: USER User Name

The effective user name of the task's owner.

f: GROUP Group Name

The effective group name of the task's owner.

g: TTY Controlling Tty

The name of the controlling terminal. This is usually the device (serial port, pty, etc.) from which the process was started, and which it uses for input or output. However, a task need not be associated with a terminal, in which case you'll see '?' displayed.

h: PR Priority

The priority of the task.

i: NI Nice value

The nice value of the task. A negative nice value means higher priority, whereas a positive nice value means lower priority. Zero in this field simply means priority will not be adjusted in determining a task's dispatchability.

j: P Last used (SMP)

A number representing the last used processor. In a true SMP environment this will likely change frequently since the kernel intentionally uses weak affinity. Also, the very act of running may break this weak affinity and cause more processes to change s more often (because of the extra demand for time).

k: %CPU usage

The task's share of the elapsed time since the last screen update, expressed as a percentage of total time. In a true SMP environment, if 'Irix mode' is F, will operate in number of s. You toggle 'Irix/Solaris' modes with the 'I' .

l: TIME Time

Total time the task has used since it started. When 'Cumulative mode' is O, each process is listed with the time that it and its dead children has used. You toggle 'Cumulative mode' with 'S', which is a and an . 'S' for additional information regarding this mode.

m: TIME+ Time, hundredths

The same as 'TIME', but reflecting more granularity through hundredths of a second.

n: %MEM Memory usage (RES)

A task's currently used share of available .

o: VIRT Virtual Image (kb)

The total amount of used by the task. It includes all code, data and shared libraries plus pages that have been swapped out.

VIRT = SWAP + RES.

p: SWAP Swapped size (kb)

The swapped out portion of a task's total image.

q: RES Resident size (kb)

The non-swapped a task has used.

RES = CODE + DATA.

r: CODE Code size (kb)

The amount of devoted to executable code, also known as the 'text resident set' size or TRS.

s: DATA Data+Stack size (kb)

The amount of devoted to other than executable code, also known as the 'data resident set' size or DRS.

t: SHR Shared Mem size (kb)

The amount of used by a task. It simply reflects memory that could be potentially shared with other processes.

u: nFLT Page Fault count

The number of major page faults that have occurred for a task. A page fault occurs when a process attempts to read from or write to a virtual page that is not currently present in its address space. A major page fault is when backing storage access (such as a disk) is involved in making that page available.

v: nDRT Dirty Pages count

The number of pages that have been modified since they were last written to disk. Dirty pages must be written to disk before the corresponding physical memory location can be used for some other virtual page.

w: S Process Status

The status of the task which can be one of: 'D' = uninterruptible sleep 'R' = running 'S' = sleeping 'T' = traced or stopped 'Z' = zombie

Tasks shown as running should be more properly thought of as 'ready to run' their task_struct is simply represented on the Linux run-queue. Even without a true SMP machine, you may see numerous tasks in this state depending on 's delay interval and nice value.

x: Command Command line or Program name

Display the command line used to start a task or the name of the associated program. You toggle between command line and name with 'c', which is both a and an .

When you've chosen to display command lines, processes without a command line (like kernel threads) will be shown with only the program name in parentheses, as in this example: ( mdrecoveryd )

Either form of display is subject to potential truncation if it's too long to fit in this field's current width. That width depends upon other fields selected, their order and the current screen width.

The 'Command' field/column is unique, in that it is not fixed-width. When displayed, this column will be allocated all remaining screen width (up to the maximum 512 characters) to provide for the potential growth of program names into command lines.

y: WCHAN Sleeping in Function

Depending on the availability of the kernel link map ('System.map'), this field will show the name or the address of the kernel function in which the task is currently sleeping. Running tasks will display a dash ('-') in this column.

By displaying this field, 's own working set will be increased by over 700Kb. Your only means of reducing that overhead will be to stop and restart .

z: Flags Task Flags

This column represents the task's current scheduling flags which are expressed in hexadecimal notation and with zeros suppressed. These flags are officially documented in <linux/sched.h>. Less formal documentation can also be found on the 'Fields select' and 'Order fields' screens.

After pressing the s 'f' (Fields select) or 'o' (Order fields) you will be shown a screen containing the current fields string followed by names and descriptions for all fields.

Here is a sample fields string from one of 's four windows/field groups and an explanation of the conventions used: Sample fields string: ANOPQRSTUVXbcdefgjlmyzWHIK The order of displayed fields corresponds to the order of the letters in that string. If the letter is upper case the corresponding field itself will then be shown as part of the (screen width permitting). This will also be indicated by a leading , as in this excerpt: ... * K: %CPU = CPU usage l: TIME = CPU Time m: TIME+ = CPU Time, hundredths * N: %MEM = Memory usage (RES) * O: VIRT = Virtual Image (kb) ...

Fields select screen the 'f'

You toggle the display of a field by simply pressing the corresponding letter.

Order fields screen the 'o'

You move a field to the left by pressing the corresponding upper case letter and to the right with the lower case letter.

The global s are always available in both and . However, some of these s are not available when running in 'Secure mode'.

If you wish to know in advance whether or not your has been secured, simply ask for help and view the system summary on the second line.

<Enter> or <Space> :Refresh_Display

These commands do nothing, they are simply ignored. However, they will awaken and following receipt of any input the entire display will be repainted.

Use either of these keys if you have a large delay interval and wish to see current status,

<?> or <h> :Help

There are two help levels available. The first will provide a reminder of all the basic s. If is secured, that screen will be abbreviated.

Typing 'h' or '?' on that help screen will take you to help for those s applicable to .

<=> :Exit_Task_Limits

Removes restrictions on which tasks are shown. This command will reverse any 'i' (idle tasks) and 'n' (max tasks) commands that might be active. It also provides for an 'exit' from PID monitoring. See the '-p' for a discussion of PID monitoring.

When operating in this command has a slightly broader meaning.

<A> :Alternate_Display_Mode_toggle

This command will switch between and . 4. ALTERNATE-DISPLAY Mode and the 'G' for insight into s and field groups.

<B> :Bold_Disable/Enable_toggle

This command will influence use of the 'bold' terminfo capability and alters both the and for the . While it is intended primarily for use with dumb terminals, it can be applied anytime.

When this toggle is O and is operating in monochrome mode, the entire display will appear as normal text. Thus, unless the 'x' and/or 'y' toggles are using reverse for emphasis, there will be no visual confirmation that they are even on.

* <d> or <s> :Change_Delay_Time_interval

You will be prompted to enter the delay time, in seconds, between display updates.

Fractional seconds are honored, but a negative number is not allowed. Entering 0 causes (nearly) continuous updates, with an unsatisfactory display as the system and tty driver try to keep up with 's demands. The delay value is inversely proportional to system loading, so set it with care.

If at any time you wish to know the current delay time, simply ask for help and view the system summary on the second line.

<G> :Choose_Another_Window/Field_Group

You will be prompted to enter a number between 1 and 4 designating the window/field group which should be made the . You will soon grow comfortable with these 4 windows, especially after experimenting with .

<I> :Irix/Solaris_Mode_toggle

When operating in 'Solaris mode' ('I' toggled F), a task's usage will be divided by the total number of s. After issuing this command, you'll be informed of the new state of this toggle.

<u> :select a user

You will be prompted for a UID or username. Only processes belonging to the selected user will be displayed. This option matches on the effective UID.

<U> :select a user

You will be prompted for a UID or username. Only processes belonging to the selected user will be displayed. This option matches on the real, effective, saved, and filesystem UID.

* <k> :Kill_a_task

You will be prompted for a PID and then the signal to send. The default signal, as reflected in the prompt, is SIGTERM. However, you can send any signal, via number or name.

If you wish to abort the kill process, do one of the following depending on your progress: 1) at the pid prompt, just press <Enter> 2) at the signal prompt, type 0

<q> :Quit

* <r> :Renice_a_Task

You will be prompted for a PID and then the value to nice it to. Entering a positive value will cause a process to lose priority. Conversely, a negative value will cause a process to be viewed more favorably by the kernel.

<W> :Write_the_Configuration_File

This will save all of your options and toggles plus the current display mode and delay time. By issuing this command just before quitting , you will be able restart later in exactly that same state.

<Z> :Change_Color_Mapping This key will take you to a separate screen where you can change the colors for the , or for all windows. For details regarding this 3d. COLOR Mapping.

*

The commands shown with an are not available in 'Secure mode', nor will they be shown on the level-1 help screen.

The s are always available in both and . They affect the beginning lines of your display and will determine the position of messages and prompts.

These commands always impact just the /field group. 4. ALTERNATE-DISPLAY Mode and the 'G' for insight into s and field groups.

<l> :Toggle_Load_Average/Uptime On/Off

This is also the line containing the program name (possibly an alias) when operating in or the name when operating in .

<m> :Toggle_Memory/Swap_Usage On/Off

This command affects two lines.

<t> :Toggle_Task/Cpu_States On/Off

This command affects from 2 to many lines, depending on the state of the '1' toggle and whether or not is running under true SMP.

<1> :Toggle_Single/Separate_Cpu_States On/Off

This command affects how the 't' command's Cpu States portion is shown. Although this toggle exists primarily to serve massively-parallel SMP machines, it is not restricted to solely SMP environments.

When you see 'Cpu(s):' in the , the '1' toggle is O and all information is gathered in a single line. Otherwise, each is displayed separately as: 'Cpu0, Cpu1, ...'

If the entire has been toggled F for any window, you would be left with just the message line. In that way, you will have maximized available task rows but (temporarily) sacrificed the program name in or the name when in .

The s are always available in .

The s are never available in if the 's has been toggled F ( 4. ALTERNATE-DISPLAY Mode).

APPEARANCE of

The following commands will also be influenced by the state of the global 'B' (bold disable) toggle.

<b> :Bold/Reverse_toggle

This command will impact how the 'x' and 'y' toggles are displayed. Further, it will only be available when at least one of those toggles is O.

<x> :Column_Highlight_toggle

Changes highlighting for the current sort field. You probably don't need a constant visual reminder of the sort field and hopes that you always run with 'column highlight' F, due to the cost in path-length.

If you forget which field is being sorted this command can serve as a quick visual reminder.

<y> :Row_Highlight_toggle

Changes highlighting for "running" tasks. For additional insight into this task state, 2a. DESCRIPTIONS of Fields, Process Status.

Use of this provision provides important insight into your system's health. The only costs will be a few additional tty escape sequences.

<z> :Color/Monochrome_toggle

Switches the between your last used color scheme and the older form of black-on-white or white-on-black. This command will alter both the and but does not affect the state of the 'x', 'y' or 'b' toggles.

CONTENT of

<c> :Command_Line/Program_Name_toggle

This command will be honored whether or not the 'Command' column is currently visible. Later, should that field come into view, the change you applied will be seen.

<f> and <o> :Fields_select or Order_fields

These keys display separate screens where you can change which fields are displayed and their order. For additional information on these s 2b. SELECTING and ORDERING Columns.

<S> :Cumulative_Time_Mode_toggle

When 'Cumulative mode' is O, each process is listed with the time that it and its dead children have used.

When F, programs that fork into many separate tasks will appear less demanding. For programs like 'init' or a shell this is appropriate but for others, like compilers, perhaps not. Experiment with two s sharing the same sort field but with different 'S' states and see which representation you prefer.

After issuing this command, you'll be informed of the new state of this toggle. If you wish to know in advance whether or not 'Cumulative mode' is in effect, simply ask for help and view the window summary on the second line.

<u> :Show_Specific_User_Only

You will be prompted to enter the name of the user to display. Thereafter, in that only matching User ID's will be shown, or possibly no tasks will be shown.

Later, if you wish to monitor all tasks again, re-issue this command but just press <Enter> at the prompt, without providing a name.

SIZE of

<i> :Idle_Processes_toggle

Displays all tasks or just active tasks. When this toggle is F, idled or zombied processes will not be displayed.

If this command is applied to the last when in , then it will not affect the window's size, as all prior s will have already been painted.

<n> or <#> :Set_Maximum_Tasks

You will be prompted to enter the number of tasks to display. The lessor of your number and available screen rows will be used.

When used in , this is the command that gives you precise control over the size of each currently visible , except for the very last. It will not affect the last window's size, as all prior s will have already been painted.

If you wish to increase the size of the last visible when in , simply decrease the size of the (s) above it.

SORTING of

For compatibility, this supports most of the former sort keys. Since this is primarily a service to former users, these commands do not appear on any help screen. command sorted field supported A start time (non-display) No M %MEM Yes N PID Yes P %CPU Yes T TIME+ Yes

Before using any of the following sort provisions, suggests that you temporarily turn on column highlighting using the 'x' . That will help ensure that the actual sort environment matches your intent.

The following s will only be honored when the current sort field is visible. The sort field might not be visible because: 1) there is insufficient Screen Width 2) the 'f' turned it F

<<> :Move_Sort_Field_Left

Moves the sort column to the left unless the current sort field is the first field being displayed.

<>> :Move_Sort_Field_Right

Moves the sort column to the right unless the current sort field is the last field being displayed.

The following s will always be honored whether or not the current sort field is visible.

<F> or <O> :Select_Sort_Field

These keys display a separate screen where you can change which field is used as the sort column.

If a field is selected which was not previously being displayed, it will be forced O when you return to the display. However, depending upon your screen width and the order of your fields, this sort field may not be displayable.

This can be a convenient way to simply verify the current sort field, when running with column highlighting turned F.

<R> :Reverse/Normal_Sort_Field_toggle

Using this you can alternate between high-to-low and low-to-high sorts.

Field sorting uses internal values, not those in column display. Thus, the TTY and WCHAN fields will violate strict ASCII collating sequence.

When you issue the 'Z' , you will be presented with a separate screen. That screen can be used to change the colors in just the or in all four windows before returning to the display.

Available s 4 upper case letters to select a target 8 numbers to select a color normal toggles available 'B' :bold disable/enable 'b' :running tasks "bold"/reverse 'z' :color/mono other commands available 'a'/'w' :apply, then go to next/prior <Enter> :apply and exit 'q' :abandon current changes and exit

If your use 'a' or 'w' to cycle the targeted window, you will have applied the color scheme that was displayed when you left that window. You can, of course, easily return to any window and reapply different colors or turn colors F completely with the 'z' toggle.

The Color Mapping screen can also be used to change the /field group in either or . Whatever was targeted when 'q' or <Enter> was pressed will be made current as you return to the display.

Field Groups/Windows:

In there is a single window represented by the entire screen. That single window can still be changed to display 1 of 4 different field groups ( 'G' , repeated below). Each of the 4 field groups has a unique separately configurable and its own configurable .

In , those 4 underlying field groups can now be made visible simultaneously, or can be turned F individually at your command.

The will always exist, even if it's only the message line. At any given time only one can be displayed. However, depending on your commands, there could be from zero to four separate s currently showing on the screen.

Current Window:

The is the window associated with the and the window to which task related commands are always directed. Since in you can toggle the F, some commands might be restricted for the .

A further complication arises when you have toggled the first line F. With the loss of the window name (the 'l' toggled line), you'll not easily know what window is the .

<-> and <_> :Show/Hide_Window(s)_toggles

The '-' key turns the 's O and F. When O, that will show a minimum of the columns header you've established with the 'f' and 'o' commands. It will also reflect any other options/toggles you've applied yielding zero or more tasks.

The '_' key does the same for all s. In other words, it switches between the currently visible (s) and any (s) you had toggled F. If all 4 s are currently visible, this will leave the as the only display element.

* <=> and <+> :Equalize_(re-balance)_Window(s)

The '=' key forces the 's to be visible. It also reverses any 'i' (idle tasks) and 'n' (max tasks) commands that might be active.

The '+' key does the same for all windows. The four s will reappear, evenly balanced. They will also have retained any customizations you had previously applied, except for the 'i' (idle tasks) and 'n' (max tasks) commands.

* <A> :Alternate_Display_Mode_toggle

This command will switch between and .

The first time you issue this command, all four s will be shown. Thereafter when you switch modes, you will see only the (s) you've chosen to make visible.

* <a> and <w> :Next_Window_Forward/Backward

This will change the , which in turn changes the window to which commands are directed. These keys act in a circular fashion so you can reach any desired using either key.

Assuming the window name is visible (you have not toggled 'l' F), whenever the name loses its emphasis/color, that's a reminder the is F and many commands will be restricted.

* <G> :Choose_Another_Window/Field_Group

You will be prompted to enter a number between 1 and 4 designating the window/field group which should be made the .

In , this command is necessary to alter the . In , it is simply a less convenient alternative to the 'a' and 'w' commands.

<g> :Change_Window/Field_Group_Name

You will be prompted for a new name to be applied to the . It does not require that the window name be visible (the 'l' toggle to be O).

*

The s shown with an have use beyond . '=', 'A', 'G' are always available 'a', 'w' act the same when color mapping

The presence of this file will influence which version of the 'help' screen is shown to an ordinary user. More importantly, it will limit what ordinary users are allowed to do when is running. They will not be able to issue the following commands. k Kill a task r Renice a task d or s Change delay/sleep interval

The system is not created by . Rather, you create this file manually and place it in the /etc directory. Its name must be 'toprc' and must have no leading '.' (period). It must have only two lines.

Here is an example of the contents of /etc/toprc: s # line 1: 'secure' mode switch 5.0 # line 2: 'delay' interval in seconds

This file is written as '$HOME/.your-name-4-top' + 'rc'. Use the 'W' to create it or update it.

Here is the general layout: global # line 1: the program name/alias notation " # line 2: id,altscr,irixps,delay,curwin per ea # line a: winname,fieldscur window # line b: winflags,sortindx,maxtasks " # line c: summclr,msgsclr,headclr,taskclr

If the $HOME variable is not present, will try to write the personal to the current directory, subject to permissions.

For these stupid tricks, needs .

The user interface, through prompts and help, intentionally implies that the delay interval is limited to tenths of a second. However, you're free to set any desired delay. If you want to see Linux at his scheduling best, try a delay of .09 seconds or less.

For this experiment, under x-windows open an xterm and maximize it. Then do the following: . provide a scheduling boost and tiny delay via: nice -n -10 top -d.09 . keep sorted column highlighting F to minimize path length . turn O reverse row highlighting for emphasis . try various sort columns (TIME/MEM work well), and normal or reverse sorts to bring the most active processes into view

What you'll see is a very busy Linux doing what he's always done for you, but there was no program available to illustrate this.

Under an xterm using 'white-on-black' colors, try setting 's task color to black and be sure that task highlighting is set to bold, not reverse. Then set the delay interval to around .3 seconds.

After bringing the most active processes into view, what you'll see are the ghostly images of just the currently running tasks.

Delete the existing rcfile, or create a new symlink. Start this new version then type 'T' (a secret key, 3c. TASK Area Commands, Sorting) followed by 'W' and 'q'. Finally, restart the program with -d0 (zero delay).

Your display will be refreshed at three times the rate of the former , a 300% speed advantage. As climbs the TIME ladder, be as patient as you can while speculating on whether or not will ever reach the .

For these stupid tricks, needs .

With 3 or 4 s visible, pick any window other than the last and turn idle processes F. Depending on where you applied 'i', sometimes several s are bouncing and sometimes it's like an accordion, as tries his best to allocate space.

Set each window's summary lines differently: one with no memory; another with no states; maybe one with nothing at all, just the message line. Then hold down 'a' or 'w' and watch a variation on bouncing windows hopping windows.

Display all 4 windows and for each, in turn, set idle processes to F. You've just entered the "extreme bounce" zone.

This stupid trick also requires .

Display all 4 windows and make sure that 1:Def is the . Then, keep increasing window size until the all the other s are "pushed out of the nest".

When they've all been displaced, toggle between all visible/invisible windows. Then ponder this:

is fibbing or telling honestly your imposed truth?

The purpose of this License is to make a manual, textbook, or other written document "free" in the sense of freedom: to assure everyone the effective freedom to copy and redistribute it, with or without modifying it, either commercially or noncommercially. Secondarily, this License preserves for the author and publisher a way to get credit for their work, while not being considered responsible for modifications made by others.

This License is a kind of "copyleft", which means that derivative works of the document must themselves be free in the same sense. It complements the GNU General Public License, which is a copyleft license designed for free software.

We have designed this License in order to use it for manuals for free software, because free software needs free documentation: a free program should come with manuals providing the same freedoms that the software does. But this License is not limited to software manuals; it can be used for any textual work, regardless of subject matter or whether it is published as a printed book. We recommend this License principally for works whose purpose is instruction or reference.

This License applies to any manual or other work that contains a notice placed by the copyright holder saying it can be distributed under the terms of this License. The "Document", below, refers to any such manual or work. Any member of the public is a licensee, and is addressed as "you".

A "Modified Version" of the Document means any work containing the Document or a portion of it, either copied verbatim, or with modifications and/or translated into another language.

A "Secondary Section" is a named appendix or a front-matter section of the Document that deals exclusively with the relationship of the publishers or authors of the Document to the Document's overall subject (or to related matters) and contains nothing that could fall directly within that overall subject. (For example, if the Document is in part a textbook of mathematics, a Secondary Section may not explain any mathematics.) The relationship could be a matter of historical connection with the subject or with related matters, or of legal, commercial, philosophical, ethical or political position regarding them.

The "Invariant Sections" are certain Secondary Sections whose titles are designated, as being those of Invariant Sections, in the notice that says that the Document is released under this License.

The "Cover Texts" are certain short passages of text that are listed, as Front-Cover Texts or Back-Cover Texts, in the notice that says that the Document is released under this License.

A "Transparent" copy of the Document means a machine-readable copy, represented in a format whose specification is available to the general public, whose contents can be viewed and edited directly and straightforwardly with generic text editors or (for images composed of pixels) generic paint programs or (for drawings) some widely available drawing editor, and that is suitable for input to text formatters or for automatic translation to a variety of formats suitable for input to text formatters. A copy made in an otherwise Transparent file format whose markup has been designed to thwart or discourage subsequent modification by readers is not Transparent. A copy that is not "Transparent" is called "Opaque".

Examples of suitable formats for Transparent copies include plain ASCII without markup, Texinfo input format, LaTeX input format, SGML or XML using a publicly available DTD, and standard-conforming simple HTML designed for human modification. Opaque formats include PostScript, PDF, proprietary formats that can be read and edited only by proprietary word processors, SGML or XML for which the DTD and/or processing tools are not generally available, and the machine-generated HTML produced by some word processors for output purposes only.

The "Title Page" means, for a printed book, the title page itself, plus such following pages as are needed to hold, legibly, the material this License requires to appear in the title page. For works in formats which do not have any title page as such, "Title Page" means the text near the most prominent appearance of the work's title, preceding the beginning of the body of the text.

You may copy and distribute the Document in any medium, either commercially or noncommercially, provided that this License, the copyright notices, and the license notice saying this License applies to the Document are reproduced in all copies, and that you add no other conditions whatsoever to those of this License. You may not use technical measures to obstruct or control the reading or further copying of the copies you make or distribute. However, you may accept compensation in exchange for copies. If you distribute a large enough number of copies you must also follow the conditions in section 3.

You may also lend copies, under the same conditions stated above, and you may publicly display copies.

If you publish printed copies of the Document numbering more than 100, and the Document's license notice requires Cover Texts, you must enclose the copies in covers that carry, clearly and legibly, all these Cover Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on the back cover. Both covers must also clearly and legibly identify you as the publisher of these copies. The front cover must present the full title with all words of the title equally prominent and visible. You may add other material on the covers in addition. Copying with changes limited to the covers, as long as they preserve the title of the Document and satisfy these conditions, can be treated as verbatim copying in other respects.

If the required texts for either cover are too voluminous to fit legibly, you should put the first ones listed (as many as fit reasonably) on the actual cover, and continue the rest onto adjacent pages.

If you publish or distribute Opaque copies of the Document numbering more than 100, you must either include a machine-readable Transparent copy along with each Opaque copy, or state in or with each Opaque copy a publicly-accessible computer-network location containing a complete Transparent copy of the Document, free of added material, which the general network-using public has access to download anonymously at no charge using public-standard network protocols. If you use the latter option, you must take reasonably prudent steps, when you begin distribution of Opaque copies in quantity, to ensure that this Transparent copy will remain thus accessible at the stated location until at least one year after the last time you distribute an Opaque copy (directly or through your agents or retailers) of that edition to the public.

It is requested, but not required, that you contact the authors of the Document well before redistributing any large number of copies, to give them a chance to provide you with an updated version of the Document.

You may copy and distribute a Modified Version of the Document under the conditions of sections 2 and 3 above, provided that you release the Modified Version under precisely this License, with the Modified Version filling the role of the Document, thus licensing distribution and modification of the Modified Version to whoever possesses a copy of it. In addition, you must do these things in the Modified Version:

If the Modified Version includes new front-matter sections or appendices that qualify as Secondary Sections and contain no material copied from the Document, you may at your option designate some or all of these sections as invariant. To do this, add their titles to the list of Invariant Sections in the Modified Version's license notice. These titles must be distinct from any other section titles.

You may add a section entitled "Endorsements", provided it contains nothing but endorsements of your Modified Version by various parties--for example, statements of peer review or that the text has been approved by an organization as the authoritative definition of a standard.

You may add a passage of up to five words as a Front-Cover Text, and a passage of up to 25 words as a Back-Cover Text, to the end of the list of Cover Texts in the Modified Version. Only one passage of Front-Cover Text and one of Back-Cover Text may be added by (or through arrangements made by) any one entity. If the Document already includes a cover text for the same cover, previously added by you or by arrangement made by the same entity you are acting on behalf of, you may not add another; but you may replace the old one, on explicit permission from the previous publisher that added the old one.

The author(s) and publisher(s) of the Document do not by this License give permission to use their names for publicity for or to assert or imply endorsement of any Modified Version.

You may combine the Document with other documents released under this License, under the terms defined in section 4 above for modified versions, provided that you include in the combination all of the Invariant Sections of all of the original documents, unmodified, and list them all as Invariant Sections of your combined work in its license notice.

The combined work need only contain one copy of this License, and multiple identical Invariant Sections may be replaced with a single copy. If there are multiple Invariant Sections with the same name but different contents, make the title of each such section unique by adding at the end of it, in parentheses, the name of the original author or publisher of that section if known, or else a unique number. Make the same adjustment to the section titles in the list of Invariant Sections in the license notice of the combined work.

In the combination, you must combine any sections entitled "History" in the various original documents, forming one section entitled "History"; likewise combine any sections entitled "Acknowledgements", and any sections entitled "Dedications". You must delete all sections entitled "Endorsements."

You may make a collection consisting of the Document and other documents released under this License, and replace the individual copies of this License in the various documents with a single copy that is included in the collection, provided that you follow the rules of this License for verbatim copying of each of the documents in all other respects.

You may extract a single document from such a collection, and distribute it individually under this License, provided you insert a copy of this License into the extracted document, and follow this License in all other respects regarding verbatim copying of that document.

A compilation of the Document or its derivatives with other separate and independent documents or works, in or on a volume of a storage or distribution medium, does not as a whole count as a Modified Version of the Document, provided no compilation copyright is claimed for the compilation. Such a compilation is called an "aggregate", and this License does not apply to the other self-contained works thus compiled with the Document, on account of their being thus compiled, if they are not themselves derivative works of the Document.

If the Cover Text requirement of section 3 is applicable to these copies of the Document, then if the Document is less than one quarter of the entire aggregate, the Document's Cover Texts may be placed on covers that surround only the Document within the aggregate. Otherwise they must appear on covers around the whole aggregate.

Translation is considered a kind of modification, so you may distribute translations of the Document under the terms of section 4. Replacing Invariant Sections with translations requires special permission from their copyright holders, but you may include translations of some or all Invariant Sections in addition to the original versions of these Invariant Sections. You may include a translation of this License provided that you also include the original English version of this License. In case of a disagreement between the translation and the original English version of this License, the original English version will prevail.

You may not copy, modify, sublicense, or distribute the Document except as expressly provided for under this License. Any other attempt to copy, modify, sublicense or distribute the Document is void, and will automatically terminate your rights under this License. However, parties who have received copies, or rights, from you under this License will not have their licenses terminated so long as such parties remain in full compliance.

The Free Software Foundation may publish new, revised versions of the GNU Free Documentation License from time to time. Such new versions will be similar in spirit to the present version, but may differ in detail to address new problems or concerns. See http://www.gnu.org/copyleft/.

Each version of the License is given a distinguishing version number. If the Document specifies that a particular numbered version of this License "or any later version" applies to it, you have the option of following the terms and conditions either of that specified version or of any later version that has been published (not as a draft) by the Free Software Foundation. If the Document does not specify a version number of this License, you may choose any version ever published (not as a draft) by the Free Software Foundation.

To use this License in a document you have written, include a copy of the License in the document and put the following copyright and license notices just after the title page:

Copyright (c) YEAR YOUR NAME.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.1 or any later version published by the Free Software Foundation; with the Invariant Sections being LIST THEIR TITLES, with the Front-Cover Texts being LIST, and with the Back-Cover Texts being LIST. A copy of the license is included in the section entitled "GNU Free Documentation License".

If you have no Invariant Sections, write "with no Invariant Sections" instead of saying which ones are invariant. If you have no Front-Cover Texts, write "no Front-Cover Texts" instead of "Front-Cover Texts being LIST"; likewise for Back-Cover Texts.

If your document contains nontrivial examples of program code, we recommend releasing these examples in parallel under your choice of free software license, such as the GNU General Public License, to permit their use in free software.