Question Extract file

[Eric_03]

Hi,

How to extract only files with PEZ character 10, 11 and 12 in file name from this code:

using SharpCompress.Common;
using SharpCompress.Readers;
using System;
using System.IO;

namespace ExcelWorkbook1
{
    class SharpCompress
    {
        public static void UnTAR(String tarFilePath, string uncompressFolderPath)
        {
            using (Stream stream = File.OpenRead(tarFilePath))
            {
                var reader = ReaderFactory.Open(stream);
                while (reader.MoveToNextEntry())
                {
                    if (!reader.Entry.IsDirectory)
                    {
                        ExtractionOptions opt = new ExtractionOptions
                        {
                            ExtractFullPath = true,
                            Overwrite = true
                        };
                        reader.WriteEntryToDirectory(uncompressFolderPath, opt);
                    }
                }
            }
        }
    }
}

thank you

Eric

 

[Skydiver]

Did you look at the documentation for that library you are using? There is a high probability that Entry had other properties that just IsDirectory, like the name of the entry. You can add a condition to check that property.

 

[Eric_03]

My initial searches for the properties of this library were unsuccessful. But I continue.

Thanks

 

[Skydiver]

Since it's open source, you can look at the source code itself.

sharpcompress/IEntry.cs at 3009e6dcfd183760fbdb675249b7a65a2894618b · adamhathcock/sharpcompress

SharpCompress is a fully managed C# library to deal with many compression types and formats. - sharpcompress/IEntry.cs at 3009e6dcfd183760fbdb675249b7a65a2894618b · adamhathcock/sharpcompress

github.com

Looks like Key contains the filename. That's validated by the sample usage page (go all the way to the bottom):

sharpcompress/USAGE.md at master · adamhathcock/sharpcompress

SharpCompress is a fully managed C# library to deal with many compression types and formats. - sharpcompress/USAGE.md at master · adamhathcock/sharpcompress

github.com

 

[Eric_03]

I'll post the code as soon as I'm done

Thanks very much

Eric

 

[Eric_03]

using SharpCompress.Common;
using SharpCompress.Readers;
using System;
using System.IO;

namespace ExcelWorkbook1
{
    class SharpCompress
    {

        public static void UnTAR(String tarFilePath, string uncompressFolderPath)
        {
            using (Stream stream = File.OpenRead(tarFilePath))
            {
                var reader = ReaderFactory.Open(stream);
                while (reader.MoveToNextEntry())
                {
                    if (!reader.Entry.IsDirectory)
                    {
                        String str = reader.Entry.Key;
                        if (str.Substring(11, 3) == "PEZ")
                        {
                            ExtractionOptions opt = new ExtractionOptions
                            {
                                ExtractFullPath = true,
                                Overwrite = true
                            };
                            reader.WriteEntryToDirectory(uncompressFolderPath, opt);
                        }
                    }
                }
            }
        }
    }
}

 

[Skydiver]

Maybe better written as:

using SharpCompress.Common;
using SharpCompress.Readers;
using System;
using System.IO;

namespace ExcelWorkbook1
{
    class SharpCompress
    {
        public static void UnTarPezFiles(String tarFilePath, string uncompressFolderPath)
        {
            var extractOptions = new ExtractionOptions
            {
                ExtractFullPath = true,
                Overwrite = true
            };

            using (var stream = File.OpenRead(tarFilePath))
            using (var reader = ReaderFactory.Open(stream))
            {
                while (reader.MoveToNextEntry())
                {
                    if (!reader.Entry.IsDirectory &&
                        reader.Entry.Key.Substring(11, 3) == "PEZ")
                    {
                        reader.WriteEntryToDirectory(uncompressFolderPath, extractOptions);
                    }
                }
            }
        }
    }
}

 

[Eric_03]

Hi,

I'm beginner to c# and I don't understand why it's better to write the code like this. Can you tell me a little more please so that I can progress. I will of course replace my code with yours.

Thanks very much

Eric

 

[jmcilhinney]

• The suggested code creates the reader with a using statement, so it will be closed implicitly.
• The ExtractionOptions is only created once, instead of on every iteration of the loop.
• The code is simplified by combining two if statements into one as their separation serves no useful purpose.