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43 <H1>Frequently Asked Questions (FAQ)</H1>
46 <LI><A href="#user_faq">User FAQ</A></LI>
47 <LI><A href="#developer_faq">Developer FAQ</A></LI>
50 <H2><a name="user_faq"></a>User FAQ</H2>
52 <H4>Can I use 7-Zip in a commercial organization?</H4>
53 <P>Yes, 7-Zip is free software. You can use it on any computer. You don't need to
54 register or pay for 7-Zip.</P>
56 <H4>Why do the add, delete and update operations not work for some existing archives?</H4>
57 <P>The current version of 7-Zip can't execute some operations with .7z archives that have been
58 created with the "solid" option switched on. You can disable solid mode with -ms=off switch
61 <H4>What about ACE archive support?</H4>
62 <P>Support for ACE archives could be implemented in 7-Zip, if the source code
63 of that format was available, and the license allowed it. The Unace.dll
64 library from the authors of the ACE program is not
65 compatible with the plugin interface of 7-Zip (Unace.dll works with files, but
66 7-Zip only allows plugins to work with abstract streams). For this reason 7-Zip can't use
67 Unace.dll without a complex wrapper.</P>
69 <H4>Why doesn't the command line version add files without extensions to an archive?</H4>
70 <P>You're probably using a *.* wildcard. 7-Zip doesn't use the operating system's wildcard mask parser,
71 and consequently treats *.* as any file that has an extension.
72 To process all files you must use the * wildcard instead or omit the wildcard altogether.</P>
74 <H4>Why can't 7-Zip open some ZIP archives?</H4>
75 <P>In 99% of these cases it means that the archive contains incorrect headers.
76 Other ZIP programs can open some archives with incorrect headers, since these programs
77 just ignore errors.</P>
78 <P>If you have such archive, please don't call the 7-Zip developers about it.
79 Instead try to find the program that was used to create the archive and inform the developers
80 of that program that their software is not ZIP-compatible.</P>
82 <H4>How can I install 7-Zip in silent mode?</H4>
84 <P>Use the "/S" parameter to do a silent installation and the "/D=dir" parameter
85 to specify the "output directory". These options are case-sensitive.
86 7-Zip uses the NSIS installer by Nullsoft.</P>
89 <H2><a name="developer_faq"></a>Developer FAQ</H2>
91 <H4>Why are there linking errors when I compile 7-Zip or LZMA SDK with Visual C++ 6.0?</H4>
93 <P>To compile sources you will need Visual C++ 6.0 or a later version.
94 Some files also require a new Platform SDK from microsoft.com:</P>
95 <A href="http://www.microsoft.com/msdownload/platformsdk/sdkupdate/psdk-full.htm"><B>
96 http://www.microsoft.com/msdownload/platformsdk/sdkupdate/psdk-full.htm</B></A>
98 <A href="http://www.microsoft.com/msdownload/platformsdk/sdkupdate/"><B>
99 http://www.microsoft.com/msdownload/platformsdk/sdkupdate/</B></A>
101 <P>If you are using MSVC, specify the SDK directories at the top of the "Include files" and
102 "Library files" directory lists. These can be found under "Tools / Options / Directories".</P>
103 <P>The latest Platform SDK is not compatible with MSVC6. So you must use
104 Windows Server 2003 PSDK (February 2003) with MSVC6.</P>
106 <H4>Can I use the EXE or DLL files from 7-Zip in a Commercial Application?</H4>
108 <P>Yes, but you are required to specify in your documentation (1) that
109 you used parts of the 7-Zip program, (2) that 7-Zip is licensed under the GNU LGPL license and
110 (3) you must give a link to www.7-zip.org, where the source code can be found.</P>
112 <H4>How can I add support for 7z archives to my application?</H4>
114 <P>One way is to use the 7za.dll (available from sf.net for download). The 7za.dll
115 works via COM interfaces. It, however, doesn't use standard COM interfaces for
116 creating objects. You can find a small example in the source code. A full example is
117 7-Zip itself, since 7-Zip works via this dll also. There are other applications
118 that use 7za.dll such as WinRAR, PowerArchiver and others.</P>
120 <P>The other way is to call the command line version: 7za.exe.</P>
122 <H4>Can I use the source code of 7-Zip in a commercial application?</H4>
124 <P>Since 7-Zip is licensed under the GNU LGPL you must follow the rules of that license.
125 In brief, it means that any LGPL'ed code must remain licensed under the LGPL. For
126 instance, you can change the code from 7-Zip or write a wrapper for some code
127 from 7-Zip and compile it into a DLL; but, the source code of that DLL (including
128 your modifications / additions / wrapper) must be licensed under the LGPL or GPL.
129 Any other code in your application can be licensed as you wish.
130 This scheme allows users and developers to change LGPL'ed code and recompile
131 that DLL. That is the idea of free software. Read more here:
132 <A href="http://www.gnu.org/">http://www.gnu.org/</A>.
134 You can also read about the <A href="sdk.html">LZMA SDK</A>, which is available
135 under a more liberal license.</P>
137 <HR><P><SMALL>Copyright (C) 2008 Igor Pavlov.</SMALL></P>
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