unzip: what changed
Revision 0 to 1. Removed lines have a minus sign; added lines have a plus sign.
Title: unzip
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| 1 | + | ## Unzip and zip | |
| 2 | + | ||
| 3 | + | The unzip and zip package contains several routines to unzip or zip files on every Lazarus supported platforms. There are 4 units: | |
| 4 | + | ||
| 5 | + | - **zip** a unit which implements an zip mechanism with native Pascal links. | |
| 6 | + | - **unzip** a unit which implements an unzip mechanism with native Pascal links. | |
| 7 | + | - **ziputils** contains some tools for the unzip unit. | |
| 8 | + | - **zipbase** a unit which defines the interface for the info-zip unzip library. | |
| 9 | + | ||
| 10 | + | The zip library unit is included in Lazarus 2. | |
| 11 | + | ||
| 12 | + | ### Example | |
| 13 | + | ||
| 14 | + | Zip compression is in widespread use. It is also used to compress EPUB files. | |
| 15 | + | ||
| 16 | + | ``` pascal | |
| 17 | + | uses | |
| 18 | + | unzip,ziputils; | |
| 19 | + | const cover = 'cover.jpeg'; | |
| 20 | + | var UnZipper : unzFile; | |
| 21 | + | epubfile, UnPackPathFile : String; | |
| 22 | + | zfinfos : unz_file_info_ptr; | |
| 23 | + | i : Integer; | |
| 24 | + | li_SizeRead,li_SizeWrite,li_TotalW : Longint; | |
| 25 | + | lb_FoundFile : Boolean; | |
| 26 | + | FBuffer : TExtFileBuffer; | |
| 27 | + | li_HandleDest : Integer; | |
| 28 | + | begin | |
| 29 | + | epubfile :='/Your/Path/to/epub'; | |
| 30 | + | UnPackPathFile :='/Your/Path/to/uncompressed/file'; | |
| 31 | + | try | |
| 32 | + | UnZipper:=unzOpen(@epubfile[1]); | |
| 33 | + | if unzLocateFile(UnZipper,@cover[1],2)= UNZ_OK then | |
| 34 | + | try | |
| 35 | + | unzOpenCurrentFile(UnZipper); | |
| 36 | + | Getmem(zfinfos,SizeOf(zfinfos)); | |
| 37 | + | unzGetCurrentFileInfo(UnZipper,zfinfos,@cover[1],SizeOf(cover),nil,0,nil,0); | |
| 38 | + | lb_FoundFile := False; | |
| 39 | + | if not FileExistsUTF8(UnPackPathFile) | |
| 40 | + | Then FileCreateUTF8(UnPackPathFile); | |
| 41 | + | li_HandleDest := FileOpenUTF8(UnPackPathFile, fmopenwrite ); | |
| 42 | + | while not lb_FoundFile do | |
| 43 | + | begin | |
| 44 | + | li_SizeRead := unzReadCurrentFile(UnZipper,@FBuffer[0],high ( Fbuffer ) + 1); | |
| 45 | + | if li_SizeRead < high ( Fbuffer ) + 1 then lb_FoundFile := True; | |
| 46 | + | li_SizeWrite := Filewrite(li_HandleDest,Fbuffer,li_SizeRead); | |
| 47 | + | inc( li_TotalW, li_SizeWrite ); | |
| 48 | + | end; | |
| 49 | + | Break; | |
| 50 | + | finally | |
| 51 | + | Freemem(zfinfos,SizeOf(zfinfos)); | |
| 52 | + | end; | |
| 53 | + | finally | |
| 54 | + | try | |
| 55 | + | FileClose(li_HandleDest); | |
| 56 | + | finally | |
| 57 | + | unzCloseCurrentFile(UnZipper); | |
| 58 | + | unzClose(UnZipper); | |
| 59 | + | end; | |
| 60 | + | end; | |
| 61 | + | end. | |
| 62 | + | ``` | |
| 63 | + | ||
| 64 | + | ## See also | |
| 65 | + | ||
| 66 | + | - [[zip|zip library link]] | |
| 67 | + | - [[paszlib|paszlib: Object oriented zip file handling which does not require external libraries]] | |
| 68 | + | ||
| 69 | + | Go back to [[Package List|Packages List]] | |
| 70 | + | ||
| 71 | + | --- | |
| 72 | + | *From the Free Pascal wiki, page "unzip", as it stood on 2020-08-02 after a change by Trev, out of the wiki's dump of 2024-05-26. Copyright stays with the author who wrote it, according to the old wiki's [[Licensing]] page. If you have concerns about this material, [message the admin](/wiki-contact).* | |
| 73 | + | Category: FPC | |
| 74 | + | Category: Packages |