Grep検索でファイル検索を行う方法

Grep検索でファイル検索を行う方法
VB.NET

Private Sub btn1_Click(ByVal sender As Object, _
        ByVal e As EventArgs) Handles btn1.Click
    Dim files As String() = _
        Grep("C:\grep1", "検索したい文字列", "*.txt", False)
    Dim f As String
    For Each f In files
        Console.WriteLine(f)
    Next f
End Sub

Public Shared Function Grep(ByVal dirPath As String, _
        ByVal pattern As String, ByVal fileWildcards As String, _
        ByVal ignoreCase As Boolean) As String()
    Dim fileCol As New System.Collections.ArrayList()

    Dim opts As System.Text.RegularExpressions.RegexOptions = _
        System.Text.RegularExpressions.RegexOptions.None
    If ignoreCase Then
        opts = opts Or System.Text.RegularExpressions.RegexOptions.IgnoreCase
    End If
    Dim reg As New System.Text.RegularExpressions.Regex(pattern, opts)

    Dim dir As New System.IO.DirectoryInfo(dirPath)
    Dim files As System.IO.FileInfo() = dir.GetFiles(fileWildcards)
    Dim f As System.IO.FileInfo
    For Each f In files
        If ContainTextInFile(f.FullName, reg) Then
            fileCol.Add(f.FullName)
        End If
    Next f

    Return CType(fileCol.ToArray(GetType(String)), String())
End Function

Private Shared Function ContainTextInFile(ByVal filePath As String, _
        ByVal reg As System.Text.RegularExpressions.Regex) As Boolean
    Dim strm As System.IO.StreamReader = Nothing
    Dim txt As String = ""
    Try
        strm = New System.IO.StreamReader( _
            filePath, System.Text.Encoding.Default, True)
        txt = strm.ReadToEnd()
    Finally
        strm.Close()
    End Try

    Return reg.IsMatch(txt)
End Function

C#

private void btn1_Click(object sender, EventArgs e)
{
    string[] files = Grep("C:\\docs1", "検索したい文字列", "*.txt", false);
    foreach (string f in files)
    {
        Console.WriteLine(f);
    }
}

public static string[] Grep(
    string dirPath, string pattern, string fileWildcards, bool ignoreCase)
{
    System.Collections.ArrayList fileCol =
        new System.Collections.ArrayList();

    System.Text.RegularExpressions.RegexOptions opts =
        System.Text.RegularExpressions.RegexOptions.None;
    if (ignoreCase)
        opts |= System.Text.RegularExpressions.RegexOptions.IgnoreCase;
    System.Text.RegularExpressions.Regex reg =
        new System.Text.RegularExpressions.Regex(pattern, opts);

    System.IO.DirectoryInfo dir = new System.IO.DirectoryInfo(dirPath);
    System.IO.FileInfo[] files = dir.GetFiles(fileWildcards);
    foreach (System.IO.FileInfo f in files)
    {
        if (ContainTextInFile(f.FullName, reg))
            fileCol.Add(f.FullName);
    }

    return (string[])fileCol.ToArray(typeof(string));
}

private static bool ContainTextInFile(
    string filePath, System.Text.RegularExpressions.Regex reg)
{
    System.IO.StreamReader strm = null;
    string txt = "";
    try
    {
        strm = new System.IO.StreamReader(
            filePath, System.Text.Encoding.Default, true);
        txt = strm.ReadToEnd();
    }
    finally
    {
        strm.Close();
    }

    return reg.IsMatch(txt);
}