ZipFile.OpenRead(String) Method

Definition

Namespace:

System.IO.Compression

Assembly:

System.IO.Compression.ZipFile.dll

Source:

ZipFile.Create.cs

Opens a zip archive for reading at the specified path.

public:
 static System::IO::Compression::ZipArchive ^ OpenRead(System::String ^ archiveFileName);

public static System.IO.Compression.ZipArchive OpenRead (string archiveFileName);

static member OpenRead : string -> System.IO.Compression.ZipArchive

Public Shared Function OpenRead (archiveFileName As String) As ZipArchive

Parameters

archiveFileName

String

The path to the archive to open, specified as a relative or absolute path. A relative path is interpreted as relative to the current working directory.

Returns

ZipArchive

The opened zip archive.

Exceptions

ArgumentException

archiveFileName is Empty, contains only white space, or contains at least one invalid character.

ArgumentNullException

archiveFileName is null.

PathTooLongException

In archiveFileName, the specified path, file name, or both exceed the system-defined maximum length.

DirectoryNotFoundException

archiveFileName is invalid or does not exist (for example, it is on an unmapped drive).

IOException

archiveFileName could not be opened.

-or-

An unspecified I/O error occurred while opening the file.

UnauthorizedAccessException

archiveFileName specifies a directory.

-or-

The caller does not have the required permission to access the file specified in archiveFileName.

FileNotFoundException

The file specified in archiveFileName is not found.

NotSupportedException

archiveFileName contains an invalid format.

InvalidDataException

archiveFileName could not be interpreted as a zip archive.

Examples

The following example shows how to open a zip archive for reading.

using System;
using System.IO;
using System.IO.Compression;

class Program
{
    static void Main(string[] args)
    {
        string zipPath = @".\result.zip";

        Console.WriteLine("Provide path where to extract the zip file:");
        string extractPath = Console.ReadLine();

        // Normalizes the path.
        extractPath = Path.GetFullPath(extractPath);

        // Ensures that the last character on the extraction path
        // is the directory separator char.
        // Without this, a malicious zip file could try to traverse outside of the expected
        // extraction path.
        if (!extractPath.EndsWith(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal))
            extractPath += Path.DirectorySeparatorChar;

        using (ZipArchive archive = ZipFile.OpenRead(zipPath))
        {
            foreach (ZipArchiveEntry entry in archive.Entries)
            {
                if (entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase))
                {
                    // Gets the full path to ensure that relative segments are removed.
                    string destinationPath = Path.GetFullPath(Path.Combine(extractPath, entry.FullName));

                    // Ordinal match is safest, case-sensitive volumes can be mounted within volumes that
                    // are case-insensitive.
                    if (destinationPath.StartsWith(extractPath, StringComparison.Ordinal))
                        entry.ExtractToFile(destinationPath);
                }
            }
        }
    }
}

open System
open System.IO;
open System.IO.Compression;

[<EntryPoint>]
let main _ =
    let zipPath = @".\result.zip"

    printfn "Provide path where to extract the zip file:"
    let extractPath = stdin.ReadLine();

    // Normalizes the path.
    let mutable extractPath = Path.GetFullPath extractPath

    // Ensures that the last character on the extraction path
    // is the directory separator char.
    // Without this, a malicious zip file could try to traverse outside of the expected
    // extraction path.
    if extractPath.EndsWith(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal) |> not then
        extractPath <- extractPath + string Path.DirectorySeparatorChar

    use archive = ZipFile.OpenRead zipPath

    for entry in archive.Entries do
        if entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase) then
            // Gets the full path to ensure that relative segments are removed.
            let destinationPath = Path.GetFullPath(Path.Combine(extractPath, entry.FullName))

            // Ordinal match is safest, case-sensitive volumes can be mounted within volumes that
            // are case-insensitive.
            if destinationPath.StartsWith(extractPath, StringComparison.Ordinal) then
                entry.ExtractToFile destinationPath
    0

Imports System.IO
Imports System.IO.Compression

Module Module1

    Sub Main()
        Dim zipPath As String = ".\result.zip"

        Console.WriteLine("Provide path where to extract the zip file:")
        Dim extractPath As String = Console.ReadLine()

        ' Normalizes the path.
        extractPath = Path.GetFullPath(extractPath)

        ' Ensures that the last character on the extraction path
        ' is the directory separator char. 
        ' Without this, a malicious zip file could try to traverse outside of the expected
        ' extraction path.
        If Not extractPath.EndsWith(Path.DirectorySeparatorChar.ToString(), StringComparison.Ordinal) Then
            extractPath += Path.DirectorySeparatorChar
        End If

        Using archive As ZipArchive = ZipFile.OpenRead(zipPath)
            For Each entry As ZipArchiveEntry In archive.Entries
                If entry.FullName.EndsWith(".txt", StringComparison.OrdinalIgnoreCase) Then

                    ' Gets the full path to ensure that relative segments are removed.
                    Dim destinationPath As String = Path.GetFullPath(Path.Combine(extractPath, entry.FullName))
                    
                    ' Ordinal match is safest, case-sensitive volumes can be mounted within volumes that
                    ' are case-insensitive.
                    If destinationPath.StartsWith(extractPath, StringComparison.Ordinal) Then 
                        entry.ExtractToFile(destinationPath)
                    End If

                End If
            Next
        End Using
    End Sub

End Module

Remarks

This method is equivalent to calling the Open method and setting the mode parameter to Read. The archive is opened with FileMode.Open as the file mode value. If the archive does not exist, a FileNotFoundException exception is thrown.