Software

The Right Tool: The 7-Zip freeware compression tool

By · October 24, 2006, 6:09 AM PST · markwkaelin

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  • 7-Zip a freeware compression tool, the right tool.

    The 7-Zip freeware compression tool does almost all standard compression methods including ZIP and TAR. It also includes its own compression format called 7z that is highly effective.

    © CNET Networks

    Josh Hoskins

  • Freeware compression tool, the right tool.

    7-Zip is a freeware compression tool. This freeware tool does almost all standard compression methods including ZIP and TAR. It also includes its own compression format called 7z that is highly effective. Another feature of 7-ZIP is that it includes GUI and command line tools. The GUI (pictured here) will be familiar to anyone who has used WinZip or WinRAR, while the command line bears similarities to many command line scanners. It also adds system integration which makes using 7-Zip a breeze.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    Creating archives within the GUI is simple. Simply browse within the explorer like interface to the files you would like to create the archive with. Select the files by highlighting them (you can select multiples by using the shift key for continuous blocks of files, or by using CTRL key for individual files). Then press the ADD button. This will bring up the add to archive window where you can select options for the creation of the archive.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    Within the Add to Archive window the first thing you will want to do is to select the name and the location where you will want to place your archive. You can name your archive anything you wish, though the file extension will change based upon the archive format you choose. 7-Zip uses standard windows browse button (an ellipsis) and the normal Windows Explorer interface for placing files.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    The next step to take is to choose the type of compression you will use. The default type is 7z, which if the format upon which 7-Zip is based. You can also choose to create your archive as either Tar or Zip. Which format you choose is up to you, but 7z has shown to be a very good choice for compression. Besides supporting file sizes up to 16000000000 GB, and offering an excellent compression ratio, the 7z format is now also available in several other compression utilities including WinRAR, PowerArchiver, and IZArc.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    Finally you will choose your compression method. This determines the depth of the compression you will use. As you move along the line from Store to Ultra there is a correlation. While the lower compression level such as Store and Fastest offer a great speed boost in creating and extracting your archive, the higher levels such as Maximum and Ultra will offer much more compression benefit creating smaller archives. You must determine what your needs are and base your choice accordingly.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    You can see from this screen the difference in file size between various compression depths and formats. You will notice that there is difference of 253 KB between the normal depth 7z and ZIP formats. This is quite a large difference in such a small archive. You will also notice that there is a substantial difference in the ZIP archives created with 7-Zip and with the built in Windows compression utility. On 7=Zips website they state that the average difference is 30 percent – 70 percent when using 7z format over ZIP, and a 2 percent – 10 percent when using 7-Zip to create ZIP archives versus other compression utilities. While this difference may not mean enough to warrant an investment in most archive tools, it is worth it while you can get it with the free 7-Zip.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    Extracting files from your archives is simple with 7-Zip. Simply navigate to your archive file. 7-Zip will display the files contained in the archive, and you can select the files you wish to extract. You can extract by dragging the files to a folder you have open, or you can press the extract button to bring up a dialog to place the files. 7-Zip has the ability to not only extract archive in the formats it writes to, but many others including RAR, CAB, and even ISO. It also includes many others. If you have questions about a specific type of format, you check out the 7-Zip forums. There are many knowledgeable and friendly people who work on this project who can help you.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    This is the extraction dialog box. From here you can choose where to place the files you extract from your archive. You can either type the location into the box, or press the ellipses to bring up a standard browsing dialog box.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    ne of the most useful parts of 7-Zip for an I.T. administrator is the 7z.exe file. This is command line version of 7-Zip that is contained in a single file. There is no need to install 7-Zip on systems that you will only use the command line on. You can place 7z.exe in a folder and call it from that location, or you can place it within one of your path folders and call it just by name. This is very nice if you are attempting to automate the archival of files on your servers or desktops via batch files.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    You can run 7z.exe with no options to see it's help dialog. While there are a plethora of options, the main ones are: a - to add files to an archive, d - to delete files within an archive, e - to extract files from an archive, and u - to update the files within an archive. This help dialog is always useful if you have questions about how to do something from the command line.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    One of the first things I will do with an install of 7-Zip is to copy the 7z.exe to my system32 directory so that I can call it by name only instead of name and path. This greatly simplifies not only working directly from the command line, but is also greatly helpful in automating your compression duties. To learn more about automating takes with Windows Task Scheduler and Batch Files please see this article on Tech Republic.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    This presents the format needed to create a new archive. You will need to call 7z.exe either from its full path or just by name if you have placed it in one of your path directories. You will then give the full path and the name of the new archive you wish to create, followed by the files you wish to compress. You can select all the files in a directory by using a wildcard as I have, or you can select individual files referencing them individually, or you can use a partial wildcard to select certain types of files, such as all Word documents by selecting *.doc.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    While working in the command line you will get progression notifier on screen. There is a countdown as each file is compressed letting you know how much of the file has been compressed. How long each file takes shows how much that file is being compressed.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    You will also see a complete listing when your archived is completed. 7z also fully returns control to your command line session once it is completed. This again is very useful for automating your compression duties.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    Extracting files from the command line is also fairly easy. One thing you must know though is that 7-Zip will extract the files to the current directory. You must make sure to navigate to the directory you wish to extract files into before you begin this process. The extraction command itself is fairly easy. You simply call 7z.exe followed by the e command to extract, then the full location of the archive folder you wish to extract.

    © CNET Networks

    Josh Hoskins

  • Freeware compression tool, the right tool.

    One useful utility in the command line 7z is the l switch. This switch allows you to view the files contained within an archive. This is very useful on large archives as the command line version is much faster than the GUI version. To use this you simply call 7z.exe followed by the l switch, then the full path to the archive you wish to view the contents of.

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    Josh Hoskins

  • Freeware compression tool, the right tool.

    7z.exe also includes the ability to manipulate archive you have already created. This is a great help if you only have certain files within an archive you wish to update. The first of these utilities is the ability to delete files within an archive. The syntax for doing this is 7z.exe and the d switch to signify delete. You will then give the full path to your file, and then the name of the file you wish to delete. This is great if you are going to use this tool for backup purposes. You can keep an up to date archive by simply deleting the files you regularly use within the archive followed by adding the files back in as seen in the next step.

    © CNET Networks

    Josh Hoskins

  • Freeware compression tool, the right tool.

    The last thing we will discuss about 7-Zip is the ability to add files to an archive. This is accomplished by using the u switch to update the archive. This is for maintaining a constantly up to date archive. This way you do not need to keep old archives, but you can keep a single archive and the update it with the changed files. If there are files you know you update constantly you can even have the automatically delete and then update in your backup archive so that it will automatically be up to date. One thing you must note about this command is that you must use it from the directory in which your archive is in. You use this switch in the following manner 7z.exe followed by the name of your archive file name and then the full path to the file (or files using wildcards) you wish to add to your archive.

    © CNET Networks

    Josh Hoskins

7-Zip a freeware compression tool, the right tool.

The 7-Zip freeware compression tool does almost all standard compression methods including ZIP and TAR. It also includes its own compression format called 7z that is highly effective.

© CNET Networks

Josh Hoskins

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By Mark Kaelin

Mark W. Kaelin has been writing and editing stories about the IT industry, gadgets, finance, accounting, and tech-life for more than 25 years. Most recently, he has been a regular contributor to BreakingModern.com, aNewDomain.net, and TechRepublic.