1<html lang="en"> 2<head> 3<title>GNU Free Documentation License - The C Preprocessor</title> 4<meta http-equiv="Content-Type" content="text/html"> 5<meta name="description" content="The C Preprocessor"> 6<meta name="generator" content="makeinfo 4.13"> 7<link title="Top" rel="start" href="index.html#Top"> 8<link rel="prev" href="Environment-Variables.html#Environment-Variables" title="Environment Variables"> 9<link rel="next" href="Index-of-Directives.html#Index-of-Directives" title="Index of Directives"> 10<link href="http://www.gnu.org/software/texinfo/" rel="generator-home" title="Texinfo Homepage"> 11<!-- 12Copyright (C) 1987, 1989, 1991, 1992, 1993, 1994, 1995, 1996, 131997, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 142008, 2009, 2010, 2011 15Free Software Foundation, Inc. 16 17Permission is granted to copy, distribute and/or modify this document 18under the terms of the GNU Free Documentation License, Version 1.3 or 19any later version published by the Free Software Foundation. A copy of 20the license is included in the 21section entitled ``GNU Free Documentation License''. 22 23This manual contains no Invariant Sections. The Front-Cover Texts are 24(a) (see below), and the Back-Cover Texts are (b) (see below). 25 26(a) The FSF's Front-Cover Text is: 27 28 A GNU Manual 29 30(b) The FSF's Back-Cover Text is: 31 32 You have freedom to copy and modify this GNU Manual, like GNU 33 software. 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It 83complements the GNU General Public License, which is a copyleft 84license designed for free software. 85 86 <p>We have designed this License in order to use it for manuals for free 87software, because free software needs free documentation: a free 88program should come with manuals providing the same freedoms that the 89software does. But this License is not limited to software manuals; 90it can be used for any textual work, regardless of subject matter or 91whether it is published as a printed book. We recommend this License 92principally for works whose purpose is instruction or reference. 93 94 <li>APPLICABILITY AND DEFINITIONS 95 96 <p>This License applies to any manual or other work, in any medium, that 97contains a notice placed by the copyright holder saying it can be 98distributed under the terms of this License. Such a notice grants a 99world-wide, royalty-free license, unlimited in duration, to use that 100work under the conditions stated herein. The “Document”, below, 101refers to any such manual or work. Any member of the public is a 102licensee, and is addressed as “you”. You accept the license if you 103copy, modify or distribute the work in a way requiring permission 104under copyright law. 105 106 <p>A “Modified Version” of the Document means any work containing the 107Document or a portion of it, either copied verbatim, or with 108modifications and/or translated into another language. 109 110 <p>A “Secondary Section” is a named appendix or a front-matter section 111of the Document that deals exclusively with the relationship of the 112publishers or authors of the Document to the Document's overall 113subject (or to related matters) and contains nothing that could fall 114directly within that overall subject. (Thus, if the Document is in 115part a textbook of mathematics, a Secondary Section may not explain 116any mathematics.) The relationship could be a matter of historical 117connection with the subject or with related matters, or of legal, 118commercial, philosophical, ethical or political position regarding 119them. 120 121 <p>The “Invariant Sections” are certain Secondary Sections whose titles 122are designated, as being those of Invariant Sections, in the notice 123that says that the Document is released under this License. If a 124section does not fit the above definition of Secondary then it is not 125allowed to be designated as Invariant. The Document may contain zero 126Invariant Sections. If the Document does not identify any Invariant 127Sections then there are none. 128 129 <p>The “Cover Texts” are certain short passages of text that are listed, 130as Front-Cover Texts or Back-Cover Texts, in the notice that says that 131the Document is released under this License. A Front-Cover Text may 132be at most 5 words, and a Back-Cover Text may be at most 25 words. 133 134 <p>A “Transparent” copy of the Document means a machine-readable copy, 135represented in a format whose specification is available to the 136general public, that is suitable for revising the document 137straightforwardly with generic text editors or (for images composed of 138pixels) generic paint programs or (for drawings) some widely available 139drawing editor, and that is suitable for input to text formatters or 140for automatic translation to a variety of formats suitable for input 141to text formatters. A copy made in an otherwise Transparent file 142format whose markup, or absence of markup, has been arranged to thwart 143or discourage subsequent modification by readers is not Transparent. 144An image format is not Transparent if used for any substantial amount 145of text. A copy that is not “Transparent” is called “Opaque”. 146 147 <p>Examples of suitable formats for Transparent copies include plain 148<span class="sc">ascii</span> without markup, Texinfo input format, LaTeX input 149format, <acronym>SGML</acronym> or <acronym>XML</acronym> using a publicly available 150<acronym>DTD</acronym>, and standard-conforming simple <acronym>HTML</acronym>, 151PostScript or <acronym>PDF</acronym> designed for human modification. Examples 152of transparent image formats include <acronym>PNG</acronym>, <acronym>XCF</acronym> and 153<acronym>JPG</acronym>. Opaque formats include proprietary formats that can be 154read and edited only by proprietary word processors, <acronym>SGML</acronym> or 155<acronym>XML</acronym> for which the <acronym>DTD</acronym> and/or processing tools are 156not generally available, and the machine-generated <acronym>HTML</acronym>, 157PostScript or <acronym>PDF</acronym> produced by some word processors for 158output purposes only. 159 160 <p>The “Title Page” means, for a printed book, the title page itself, 161plus such following pages as are needed to hold, legibly, the material 162this License requires to appear in the title page. For works in 163formats which do not have any title page as such, “Title Page” means 164the text near the most prominent appearance of the work's title, 165preceding the beginning of the body of the text. 166 167 <p>The “publisher” means any person or entity that distributes copies 168of the Document to the public. 169 170 <p>A section “Entitled XYZ” means a named subunit of the Document whose 171title either is precisely XYZ or contains XYZ in parentheses following 172text that translates XYZ in another language. (Here XYZ stands for a 173specific section name mentioned below, such as “Acknowledgements”, 174“Dedications”, “Endorsements”, or “History”.) To “Preserve the Title” 175of such a section when you modify the Document means that it remains a 176section “Entitled XYZ” according to this definition. 177 178 <p>The Document may include Warranty Disclaimers next to the notice which 179states that this License applies to the Document. These Warranty 180Disclaimers are considered to be included by reference in this 181License, but only as regards disclaiming warranties: any other 182implication that these Warranty Disclaimers may have is void and has 183no effect on the meaning of this License. 184 185 <li>VERBATIM COPYING 186 187 <p>You may copy and distribute the Document in any medium, either 188commercially or noncommercially, provided that this License, the 189copyright notices, and the license notice saying this License applies 190to the Document are reproduced in all copies, and that you add no other 191conditions whatsoever to those of this License. You may not use 192technical measures to obstruct or control the reading or further 193copying of the copies you make or distribute. However, you may accept 194compensation in exchange for copies. If you distribute a large enough 195number of copies you must also follow the conditions in section 3. 196 197 <p>You may also lend copies, under the same conditions stated above, and 198you may publicly display copies. 199 200 <li>COPYING IN QUANTITY 201 202 <p>If you publish printed copies (or copies in media that commonly have 203printed covers) of the Document, numbering more than 100, and the 204Document's license notice requires Cover Texts, you must enclose the 205copies in covers that carry, clearly and legibly, all these Cover 206Texts: Front-Cover Texts on the front cover, and Back-Cover Texts on 207the back cover. Both covers must also clearly and legibly identify 208you as the publisher of these copies. The front cover must present 209the full title with all words of the title equally prominent and 210visible. You may add other material on the covers in addition. 211Copying with changes limited to the covers, as long as they preserve 212the title of the Document and satisfy these conditions, can be treated 213as verbatim copying in other respects. 214 215 <p>If the required texts for either cover are too voluminous to fit 216legibly, you should put the first ones listed (as many as fit 217reasonably) on the actual cover, and continue the rest onto adjacent 218pages. 219 220 <p>If you publish or distribute Opaque copies of the Document numbering 221more than 100, you must either include a machine-readable Transparent 222copy along with each Opaque copy, or state in or with each Opaque copy 223a computer-network location from which the general network-using 224public has access to download using public-standard network protocols 225a complete Transparent copy of the Document, free of added material. 226If you use the latter option, you must take reasonably prudent steps, 227when you begin distribution of Opaque copies in quantity, to ensure 228that this Transparent copy will remain thus accessible at the stated 229location until at least one year after the last time you distribute an 230Opaque copy (directly or through your agents or retailers) of that 231edition to the public. 232 233 <p>It is requested, but not required, that you contact the authors of the 234Document well before redistributing any large number of copies, to give 235them a chance to provide you with an updated version of the Document. 236 237 <li>MODIFICATIONS 238 239 <p>You may copy and distribute a Modified Version of the Document under 240the conditions of sections 2 and 3 above, provided that you release 241the Modified Version under precisely this License, with the Modified 242Version filling the role of the Document, thus licensing distribution 243and modification of the Modified Version to whoever possesses a copy 244of it. In addition, you must do these things in the Modified Version: 245 246 <ol type=A start=1> 247<li>Use in the Title Page (and on the covers, if any) a title distinct 248from that of the Document, and from those of previous versions 249(which should, if there were any, be listed in the History section 250of the Document). You may use the same title as a previous version 251if the original publisher of that version gives permission. 252 253 <li>List on the Title Page, as authors, one or more persons or entities 254responsible for authorship of the modifications in the Modified 255Version, together with at least five of the principal authors of the 256Document (all of its principal authors, if it has fewer than five), 257unless they release you from this requirement. 258 259 <li>State on the Title page the name of the publisher of the 260Modified Version, as the publisher. 261 262 <li>Preserve all the copyright notices of the Document. 263 264 <li>Add an appropriate copyright notice for your modifications 265adjacent to the other copyright notices. 266 267 <li>Include, immediately after the copyright notices, a license notice 268giving the public permission to use the Modified Version under the 269terms of this License, in the form shown in the Addendum below. 270 271 <li>Preserve in that license notice the full lists of Invariant Sections 272and required Cover Texts given in the Document's license notice. 273 274 <li>Include an unaltered copy of this License. 275 276 <li>Preserve the section Entitled “History”, Preserve its Title, and add 277to it an item stating at least the title, year, new authors, and 278publisher of the Modified Version as given on the Title Page. If 279there is no section Entitled “History” in the Document, create one 280stating the title, year, authors, and publisher of the Document as 281given on its Title Page, then add an item describing the Modified 282Version as stated in the previous sentence. 283 284 <li>Preserve the network location, if any, given in the Document for 285public access to a Transparent copy of the Document, and likewise 286the network locations given in the Document for previous versions 287it was based on. These may be placed in the “History” section. 288You may omit a network location for a work that was published at 289least four years before the Document itself, or if the original 290publisher of the version it refers to gives permission. 291 292 <li>For any section Entitled “Acknowledgements” or “Dedications”, Preserve 293the Title of the section, and preserve in the section all the 294substance and tone of each of the contributor acknowledgements and/or 295dedications given therein. 296 297 <li>Preserve all the Invariant Sections of the Document, 298unaltered in their text and in their titles. Section numbers 299or the equivalent are not considered part of the section titles. 300 301 <li>Delete any section Entitled “Endorsements”. Such a section 302may not be included in the Modified Version. 303 304 <li>Do not retitle any existing section to be Entitled “Endorsements” or 305to conflict in title with any Invariant Section. 306 307 <li>Preserve any Warranty Disclaimers. 308 </ol> 309 310 <p>If the Modified Version includes new front-matter sections or 311appendices that qualify as Secondary Sections and contain no material 312copied from the Document, you may at your option designate some or all 313of these sections as invariant. To do this, add their titles to the 314list of Invariant Sections in the Modified Version's license notice. 315These titles must be distinct from any other section titles. 316 317 <p>You may add a section Entitled “Endorsements”, provided it contains 318nothing but endorsements of your Modified Version by various 319parties—for example, statements of peer review or that the text has 320been approved by an organization as the authoritative definition of a 321standard. 322 323 <p>You may add a passage of up to five words as a Front-Cover Text, and a 324passage of up to 25 words as a Back-Cover Text, to the end of the list 325of Cover Texts in the Modified Version. Only one passage of 326Front-Cover Text and one of Back-Cover Text may be added by (or 327through arrangements made by) any one entity. If the Document already 328includes a cover text for the same cover, previously added by you or 329by arrangement made by the same entity you are acting on behalf of, 330you may not add another; but you may replace the old one, on explicit 331permission from the previous publisher that added the old one. 332 333 <p>The author(s) and publisher(s) of the Document do not by this License 334give permission to use their names for publicity for or to assert or 335imply endorsement of any Modified Version. 336 337 <li>COMBINING DOCUMENTS 338 339 <p>You may combine the Document with other documents released under this 340License, under the terms defined in section 4 above for modified 341versions, provided that you include in the combination all of the 342Invariant Sections of all of the original documents, unmodified, and 343list them all as Invariant Sections of your combined work in its 344license notice, and that you preserve all their Warranty Disclaimers. 345 346 <p>The combined work need only contain one copy of this License, and 347multiple identical Invariant Sections may be replaced with a single 348copy. If there are multiple Invariant Sections with the same name but 349different contents, make the title of each such section unique by 350adding at the end of it, in parentheses, the name of the original 351author or publisher of that section if known, or else a unique number. 352Make the same adjustment to the section titles in the list of 353Invariant Sections in the license notice of the combined work. 354 355 <p>In the combination, you must combine any sections Entitled “History” 356in the various original documents, forming one section Entitled 357“History”; likewise combine any sections Entitled “Acknowledgements”, 358and any sections Entitled “Dedications”. You must delete all 359sections Entitled “Endorsements.” 360 361 <li>COLLECTIONS OF DOCUMENTS 362 363 <p>You may make a collection consisting of the Document and other documents 364released under this License, and replace the individual copies of this 365License in the various documents with a single copy that is included in 366the collection, provided that you follow the rules of this License for 367verbatim copying of each of the documents in all other respects. 368 369 <p>You may extract a single document from such a collection, and distribute 370it individually under this License, provided you insert a copy of this 371License into the extracted document, and follow this License in all 372other respects regarding verbatim copying of that document. 373 374 <li>AGGREGATION WITH INDEPENDENT WORKS 375 376 <p>A compilation of the Document or its derivatives with other separate 377and independent documents or works, in or on a volume of a storage or 378distribution medium, is called an “aggregate” if the copyright 379resulting from the compilation is not used to limit the legal rights 380of the compilation's users beyond what the individual works permit. 381When the Document is included in an aggregate, this License does not 382apply to the other works in the aggregate which are not themselves 383derivative works of the Document. 384 385 <p>If the Cover Text requirement of section 3 is applicable to these 386copies of the Document, then if the Document is less than one half of 387the entire aggregate, the Document's Cover Texts may be placed on 388covers that bracket the Document within the aggregate, or the 389electronic equivalent of covers if the Document is in electronic form. 390Otherwise they must appear on printed covers that bracket the whole 391aggregate. 392 393 <li>TRANSLATION 394 395 <p>Translation is considered a kind of modification, so you may 396distribute translations of the Document under the terms of section 4. 397Replacing Invariant Sections with translations requires special 398permission from their copyright holders, but you may include 399translations of some or all Invariant Sections in addition to the 400original versions of these Invariant Sections. You may include a 401translation of this License, and all the license notices in the 402Document, and any Warranty Disclaimers, provided that you also include 403the original English version of this License and the original versions 404of those notices and disclaimers. In case of a disagreement between 405the translation and the original version of this License or a notice 406or disclaimer, the original version will prevail. 407 408 <p>If a section in the Document is Entitled “Acknowledgements”, 409“Dedications”, or “History”, the requirement (section 4) to Preserve 410its Title (section 1) will typically require changing the actual 411title. 412 413 <li>TERMINATION 414 415 <p>You may not copy, modify, sublicense, or distribute the Document 416except as expressly provided under this License. Any attempt 417otherwise to copy, modify, sublicense, or distribute it is void, and 418will automatically terminate your rights under this License. 419 420 <p>However, if you cease all violation of this License, then your license 421from a particular copyright holder is reinstated (a) provisionally, 422unless and until the copyright holder explicitly and finally 423terminates your license, and (b) permanently, if the copyright holder 424fails to notify you of the violation by some reasonable means prior to 42560 days after the cessation. 426 427 <p>Moreover, your license from a particular copyright holder is 428reinstated permanently if the copyright holder notifies you of the 429violation by some reasonable means, this is the first time you have 430received notice of violation of this License (for any work) from that 431copyright holder, and you cure the violation prior to 30 days after 432your receipt of the notice. 433 434 <p>Termination of your rights under this section does not terminate the 435licenses of parties who have received copies or rights from you under 436this License. If your rights have been terminated and not permanently 437reinstated, receipt of a copy of some or all of the same material does 438not give you any rights to use it. 439 440 <li>FUTURE REVISIONS OF THIS LICENSE 441 442 <p>The Free Software Foundation may publish new, revised versions 443of the GNU Free Documentation License from time to time. Such new 444versions will be similar in spirit to the present version, but may 445differ in detail to address new problems or concerns. See 446<a href="http://www.gnu.org/copyleft/">http://www.gnu.org/copyleft/</a>. 447 448 <p>Each version of the License is given a distinguishing version number. 449If the Document specifies that a particular numbered version of this 450License “or any later version” applies to it, you have the option of 451following the terms and conditions either of that specified version or 452of any later version that has been published (not as a draft) by the 453Free Software Foundation. If the Document does not specify a version 454number of this License, you may choose any version ever published (not 455as a draft) by the Free Software Foundation. If the Document 456specifies that a proxy can decide which future versions of this 457License can be used, that proxy's public statement of acceptance of a 458version permanently authorizes you to choose that version for the 459Document. 460 461 <li>RELICENSING 462 463 <p>“Massive Multiauthor Collaboration Site” (or “MMC Site”) means any 464World Wide Web server that publishes copyrightable works and also 465provides prominent facilities for anybody to edit those works. A 466public wiki that anybody can edit is an example of such a server. A 467“Massive Multiauthor Collaboration” (or “MMC”) contained in the 468site means any set of copyrightable works thus published on the MMC 469site. 470 471 <p>“CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0 472license published by Creative Commons Corporation, a not-for-profit 473corporation with a principal place of business in San Francisco, 474California, as well as future copyleft versions of that license 475published by that same organization. 476 477 <p>“Incorporate” means to publish or republish a Document, in whole or 478in part, as part of another Document. 479 480 <p>An MMC is “eligible for relicensing” if it is licensed under this 481License, and if all works that were first published under this License 482somewhere other than this MMC, and subsequently incorporated in whole 483or in part into the MMC, (1) had no cover texts or invariant sections, 484and (2) were thus incorporated prior to November 1, 2008. 485 486 <p>The operator of an MMC Site may republish an MMC contained in the site 487under CC-BY-SA on the same site at any time before August 1, 2009, 488provided the MMC is eligible for relicensing. 489 490 </ol> 491 492<h3 class="unnumberedsec">ADDENDUM: How to use this License for your documents</h3> 493 494<p>To use this License in a document you have written, include a copy of 495the License in the document and put the following copyright and 496license notices just after the title page: 497 498<pre class="smallexample"> Copyright (C) <var>year</var> <var>your name</var>. 499 Permission is granted to copy, distribute and/or modify this document 500 under the terms of the GNU Free Documentation License, Version 1.3 501 or any later version published by the Free Software Foundation; 502 with no Invariant Sections, no Front-Cover Texts, and no Back-Cover 503 Texts. A copy of the license is included in the section entitled ``GNU 504 Free Documentation License''. 505</pre> 506 <p>If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts, 507replace the “with...Texts.” line with this: 508 509<pre class="smallexample"> with the Invariant Sections being <var>list their titles</var>, with 510 the Front-Cover Texts being <var>list</var>, and with the Back-Cover Texts 511 being <var>list</var>. 512</pre> 513 <p>If you have Invariant Sections without Cover Texts, or some other 514combination of the three, merge those two alternatives to suit the 515situation. 516 517 <p>If your document contains nontrivial examples of program code, we 518recommend releasing these examples in parallel under your choice of 519free software license, such as the GNU General Public License, 520to permit their use in free software. 521 522<!-- Local Variables: --> 523<!-- ispell-local-pdict: "ispell-dict" --> 524<!-- End: --> 525<!-- man end --> 526 </body></html> 527 528