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1896 | serge | 1 | |
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5 | http://zlib.net/ which may have more recent information. |
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6 | The lastest zlib FAQ is at http://zlib.net/zlib_faq.html |
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16 | file win32/DLL_FAQ.txt in the zlib distribution. Pointers to the |
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17 | precompiled DLL are found in the zlib web site at http://zlib.net/ . |
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22 | * http://marknelson.us/1997/01/01/zlib-engine/ |
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23 | * win32/DLL_FAQ.txt in the zlib distribution |
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24 | |||
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26 | |||
27 | |||
28 | buffer is equal to the available size of the compressed buffer and not |
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29 | zero. For Visual Basic, check that this parameter is passed by reference |
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30 | ("as any"), not by value ("as long"). |
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35 | When setting the parameter flush equal to Z_FINISH, also make sure that |
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36 | avail_out is big enough to allow processing all pending input. Note that a |
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37 | Z_BUF_ERROR is not fatal--another call to deflate() or inflate() can be |
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38 | made with more input or output space. A Z_BUF_ERROR may in fact be |
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39 | unavoidable depending on how the functions are used, since it is not |
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40 | possible to tell whether or not there is more output pending when |
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41 | strm.avail_out returns with zero. See http://zlib.net/zlib_how.html for a |
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42 | heavily annotated example. |
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43 | |||
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46 | |||
47 | minigzip.c, with more in examples/ . |
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48 | |||
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51 | |||
52 | zlib is rather portable and doesn't need much configuration. |
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53 | |||
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55 | |||
56 | |||
57 | Please try to reproduce the problem with a small program and send the |
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58 | corresponding source to us at zlib@gzip.org . Do not send multi-megabyte |
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59 | data files without prior agreement. |
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68 | /usr/X11R6/lib. Remove any old versions, then do "make install". |
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76 | |||
77 | distribution. |
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81 | |||
82 | the code of uncompress on your own. |
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83 | |||
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86 | |||
87 | ./configure -s |
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88 | make |
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89 | |||
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94 | |||
95 | |||
96 | |||
97 | Before going to the trouble of compiling a shared version of zlib and |
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98 | trying to install it, you may want to check if it's already there! If you |
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99 | can #include |
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100 | it. You can check the version at the top of zlib.h or with the |
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101 | ZLIB_VERSION symbol defined in zlib.h . |
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102 | |||
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104 | |||
105 | |||
106 | site: Joel Hainley, jhainley@myndkryme.com. |
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111 | http://sourceforge.net/projects/acroformtool/ . |
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112 | |||
113 | |||
114 | |||
115 | |||
116 | generates an error such as: |
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117 | |||
118 | |||
119 | symbol __register_frame_info: referenced symbol not found |
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120 | |||
121 | |||
122 | the C compiler (cc or gcc). You must recompile applications using zlib |
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123 | which have this problem. This problem is specific to Solaris. See |
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124 | http://www.sunfreeware.com for Solaris versions of zlib and applications |
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125 | using zlib. |
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126 | |||
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128 | |||
129 | |||
130 | is different and incompatible with the gzip format. The gz* functions in |
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131 | zlib on the other hand use the gzip format. Both the zlib and gzip formats |
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132 | use the same compressed data format internally, but have different headers |
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133 | and trailers around the compressed data. |
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134 | |||
135 | |||
136 | |||
137 | |||
138 | single file, such as the name and last modification date. The zlib format |
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139 | on the other hand was designed for in-memory and communication channel |
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140 | applications, and has a much more compact header and trailer and uses a |
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141 | faster integrity check than gzip. |
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142 | |||
143 | |||
144 | |||
145 | |||
146 | format using deflateInit2(). You can also request that inflate decode the |
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147 | gzip format using inflateInit2(). Read zlib.h for more details. |
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148 | |||
149 | |||
150 | |||
151 | |||
152 | provided memory allocation routines must also be thread-safe. zlib's gz* |
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153 | functions use stdio library routines, and most of zlib's functions use the |
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154 | library memory allocation routines by default. zlib's *Init* functions |
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155 | allow for the application to provide custom memory allocation routines. |
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156 | |||
157 | |||
158 | single thread at a time. |
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159 | |||
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165 | |||
166 | |||
167 | |||
168 | |||
169 | what exactly do I need to do to meet that requirement? |
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170 | |||
171 | |||
172 | particular, the final version number needs to be changed to "f", and an |
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173 | identification string should be appended to ZLIB_VERSION. Version numbers |
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174 | x.x.x.f are reserved for modifications to zlib by others than the zlib |
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175 | maintainers. For example, if the version of the base zlib you are altering |
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176 | is "1.2.3.4", then in zlib.h you should change ZLIB_VERNUM to 0x123f, and |
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177 | ZLIB_VERSION to something like "1.2.3.f-zachary-mods-v3". You can also |
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178 | update the version strings in deflate.c and inftrees.c. |
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179 | |||
180 | |||
181 | nature of the changes in zlib.h, as well as in ChangeLog and README, along |
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182 | with the dates of the alterations. The origin should include at least your |
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183 | name (or your company's name), and an email address to contact for help or |
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184 | issues with the library. |
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185 | |||
186 | |||
187 | zconf.h is also a source distribution, and so you should change |
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188 | ZLIB_VERSION and ZLIB_VERNUM and note the origin and nature of the changes |
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189 | in zlib.h as you would for a full source distribution. |
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190 | |||
191 | |||
192 | exchange compressed data between them? |
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193 | |||
194 | |||
195 | |||
196 | |||
197 | |||
198 | |||
199 | data types being limited to 32-bits in length. If you have any |
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200 | difficulties, please provide a complete problem report to zlib@gzip.org |
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201 | |||
202 | |||
203 | |||
204 | |||
205 | does PKZIP and zlib. However, you can look in zlib's contrib/blast |
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206 | directory for a possible solution to your problem. |
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207 | |||
208 | |||
209 | |||
210 | |||
211 | Z_FULL_FLUSH, carefully write all the pending data at those points, and |
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212 | keep an index of those locations, then you can start decompression at those |
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213 | points. You have to be careful to not use Z_FULL_FLUSH too often, since it |
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214 | can significantly degrade compression. Alternatively, you can scan a |
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215 | deflate stream once to generate an index, and then use that index for |
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216 | random access. See examples/zran.c . |
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217 | |||
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220 | |||
221 | were working ports of zlib 1.1.4 to MVS, but those links no longer work. |
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222 | If you know of recent, successful applications of zlib on these operating |
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223 | systems, please let us know. Thanks. |
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224 | |||
225 | |||
226 | understand the deflate format? |
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227 | |||
228 | |||
229 | contrib/puff directory. |
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230 | |||
231 | |||
232 | |||
233 | |||
234 | zlib. Look here for some more information: |
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235 | |||
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237 | |||
238 | |||
239 | |||
240 | |||
241 | Each call of inflate() or deflate() is limited to input and output chunks |
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242 | of the maximum value that can be stored in the compiler's "unsigned int" |
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243 | type, but there is no limit to the number of chunks. Note however that the |
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244 | strm.total_in and strm_total_out counters may be limited to 4 GB. These |
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245 | counters are provided as a convenience and are not used internally by |
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246 | inflate() or deflate(). The application can easily set up its own counters |
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247 | updated after each call of inflate() or deflate() to count beyond 4 GB. |
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248 | compress() and uncompress() may be limited to 4 GB, since they operate in a |
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249 | single call. gzseek() and gztell() may be limited to 4 GB depending on how |
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250 | zlib is compiled. See the zlibCompileFlags() function in zlib.h. |
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251 | |||
252 | |||
253 | if the compiler's "long" type is 32 bits. If the compiler's "long" type is |
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254 | 64 bits, then the limit is 16 exabytes. |
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255 | |||
256 | |||
257 | |||
258 | |||
259 | compiled to use sprintf() or vsprintf(), then there is no protection |
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260 | against a buffer overflow of an 8K string space (or other value as set by |
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261 | gzbuffer()), other than the caller of gzprintf() assuring that the output |
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262 | will not exceed 8K. On the other hand, if zlib is compiled to use |
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263 | snprintf() or vsnprintf(), which should normally be the case, then there is |
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264 | no vulnerability. The ./configure script will display warnings if an |
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265 | insecure variation of sprintf() will be used by gzprintf(). Also the |
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266 | zlibCompileFlags() function will return information on what variant of |
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267 | sprintf() is used by gzprintf(). |
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268 | |||
269 | |||
270 | find a portable implementation here: |
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271 | |||
272 | |||
273 | |||
274 | |||
275 | 1.1.3 and before were subject to a double-free vulnerability, and versions |
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276 | 1.2.1 and 1.2.2 were subject to an access exception when decompressing |
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277 | invalid compressed data. |
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278 | |||
279 | |||
280 | |||
281 | |||
282 | as part of the Java SDK in the java.util.zip package. If you really want |
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283 | a version of zlib written in the Java language, look on the zlib home |
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284 | page for links: http://zlib.net/ . |
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285 | |||
286 | |||
287 | up to maximally-pedantic. Can't you guys write proper code? |
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288 | |||
289 | |||
290 | in the universe. It just got to be a waste of time, and some compilers |
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291 | were downright silly as well as contradicted each other. So now, we simply |
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292 | make sure that the code always works. |
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293 | |||
294 | |||
295 | performing a conditional jump that depends on an uninitialized value. |
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296 | Isn't that a bug? |
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297 | |||
298 | |||
299 | is not affected. This only started showing up recently since zlib 1.2.x |
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300 | uses malloc() by default for allocations, whereas earlier versions used |
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301 | calloc(), which zeros out the allocated memory. Even though the code was |
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302 | correct, versions 1.2.4 and later was changed to not stimulate these |
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303 | checkers. |
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304 | |||
305 | |||
306 | data format? |
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307 | |||
308 | |||
309 | formats and associated software. |
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310 | |||
311 | |||
312 | |||
313 | |||
314 | weak and can be broken with freely available programs. To get strong |
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315 | encryption, use GnuPG, http://www.gnupg.org/ , which already includes zlib |
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316 | compression. For PKZIP compatible "encryption", look at |
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317 | http://www.info-zip.org/ |
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318 | |||
319 | |||
320 | |||
321 | |||
322 | probably have called the second one "zlib" instead to avoid confusion with |
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323 | the raw deflate compressed data format. While the HTTP 1.1 RFC 2616 |
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324 | correctly points to the zlib specification in RFC 1950 for the "deflate" |
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325 | transfer encoding, there have been reports of servers and browsers that |
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326 | incorrectly produce or expect raw deflate data per the deflate |
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327 | specficiation in RFC 1951, most notably Microsoft. So even though the |
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328 | "deflate" transfer encoding using the zlib format would be the more |
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329 | efficient approach (and in fact exactly what the zlib format was designed |
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330 | for), using the "gzip" transfer encoding is probably more reliable due to |
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331 | an unfortunate choice of name on the part of the HTTP 1.1 authors. |
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332 | |||
333 | |||
334 | |||
335 | |||
336 | |||
337 | |||
338 | they have not documented it as they have previous compression formats. In |
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339 | any case, the compression improvements are so modest compared to other more |
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340 | modern approaches, that it's not worth the effort to implement. |
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341 | |||
342 | |||
343 | |||
344 | |||
345 | Giles Vollant, which is found in the contrib directory of zlib. It is not |
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346 | part of zlib. In fact none of the stuff in contrib is part of zlib. The |
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347 | files in there are not supported by the zlib authors. You need to contact |
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348 | the authors of the respective contribution for help. |
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349 | |||
350 | |||
351 | Since it's part of zlib, doesn't that mean that all of zlib falls under the |
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352 | GNU GPL? |
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353 | |||
354 | |||
355 | other authors and are provided as a convenience to the user within the zlib |
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356 | distribution. Each item in contrib has its own license. |
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357 | |||
358 | |||
359 | |||
360 | |||
361 | |||
362 | |||
363 | so that we can use your software in our product? |
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364 | |||
365 | |||
366 |