我正在尝试在属于某个目录的某些文件中搜索特定字符串。 （搜索也在子目录中执行。目前，我提出了类似的解决方案。
继续这个直到最后一个文件。
string[] fileNames = Directory.GetFiles(@"d:\test", "*.txt", SearchOption.AllDirectories);
foreach (string sTem in fileNames)
{
foreach (string line in File.ReadAllLines(sTem))
{
if (line.Contains(SearchString))
{
MessageBox.Show("Found search string!");
break;
}
}
}
我认为可以有其他方法/方法有效且超速吗？使用批处理文件？好。另一种解决方案是使用findstr（但如何在没有批处理文件的情况下直接使用C＃程序？什么是最有效的（或者比我做的更有效？） 代码示例非常感谢！
找到另一种解决方案。
Process myproc = new Process();
myproc.StartInfo.FileName = "findstr";
myproc.StartInfo.Arguments = "/m /s /d:\"c:\\REQs\" \"madhuresh\" *.req";
myproc.StartInfo.RedirectStandardOutput = true;
myproc.StartInfo.UseShellExecute = false;
myproc.Start();
string output = myproc.StandardOutput.ReadToEnd();
myproc.WaitForExit();
这个流程的执行是否良好？也欢迎对此发表评论！
根据@ AbitChev的方法，一个时尚（我不知道它是否有效！）。无论如何，它继续这样下去。这个搜索所有目录以及子目录！
IEnumerable<string> s = from file in Directory.EnumerateFiles("c:\\directorypath", "*.req", SearchOption.AllDirectories)
from str in File.ReadLines(file)
//where str.Contains("Text@tosearched2")
where str.IndexOf(sSearchItem, StringComparison.OrdinalIgnoreCase) >= 0
select file;
foreach (string sa in s)
MessageBox.Show(sa);
（对于不区分大小写的搜索。也许这可以帮助某人。） 请评论！感谢。
答案 0 :(得分：2)
这样的事情怎么样
var found = false;
string file;
foreach (file in Directory.EnumerateFiles(
"d:\\tes\\",
"*.txt",
SearchOption.AllDirectories))
{
foreach(var line in File.ReadLines(file))
{
if (line.Contains(searchString))
{
found = ture;
break;
}
}
if (found)
{
break;
}
}
if (found)
{
var message = string.Format("Search string found in \"{0}\".", file)
MessageBox.Show(file);
}
这样做的好处是只加载内存所需的内容，而不是每个文件的内容，而不是所有文件的名称。
我注意到你正在使用String.Contains
执行序数（区分大小写和文化不敏感）比较
这将允许我们做一个简单的charachter明智比较。
我从一个小帮手函数开始
private static bool CompareCharBuffers(
char[] buffer,
int headPosition,
char[] stringChars)
{
// null checking and length comparison ommitted
var same = true;
var bufferPos = headPosition;
for (var i = 0; i < stringChars.Length; i++)
{
if (!stringChars[i].Equals(buffer[bufferPos]))
{
same = false;
break;
}
bufferPos = ++bufferPos % (buffer.Length - 1);
}
return same;
}
然后我改变以前的算法来使用这样的函数。
var stringChars = searchString.ToCharArray();
var found = false;
string file;
foreach (file in Directory.EnumerateFiles(
"d:\\tes\\",
"*.txt",
SearchOption.AllDirectories))
{
using (var reader = File.OpenText(file))
{
var buffer = new char[stringChars.Length];
if (reader.ReadBlock(buffer, 0, buffer.Length - 1)
< stringChars.Length - 1)
{
continue;
}
var head = 0;
var nextPos = buffer.Length - 1;
var nextChar = reader.Read();
while (nextChar != -1)
{
buffer[nextPos] = (char)nextChar;
if (CompareCharBuffers(buffer, head, stringChars))
{
found = ture;
break;
}
head = ++head % (buffer.Length - 1);
if (head == 0)
{
nextPos = buffer.Length - 1;
}
else
{
nextPos = head - 1;
}
nextChar = reader.Read();
}
if (found)
{
break;
}
}
}
if (found)
{
var message = string.Format("Search string found in \"{0}\".", file)
MessageBox.Show(file);
}
这只保留了搜索字符串在内存中包含的char个，并在每个文件中使用滚动缓冲区。从理论上讲，该文件可能不包含新行并使用整个磁盘，或者您的搜索字符串可能包含新行。
作为进一步的工作，我将算法的每个文件部分转换为函数并研究多线程方法。
所以这将是内部函数，
static bool FileContains(string file, char[] stringChars)
{
using (var reader = File.OpenText(file))
{
var buffer = new char[stringChars.Length];
if (reader.ReadBlock(buffer, 0, buffer.Length - 1)
< stringChars.Length - 1)
{
return false;
}
var head = 0;
var nextPos = buffer.Length - 1;
var nextChar = reader.Read();
while (nextChar != -1)
{
buffer[nextPos] = (char)nextChar;
if (CompareCharBuffers(buffer, head, stringChars))
{
return true;
}
head = ++head % (buffer.Length - 1);
if (head == 0)
{
nextPos = buffer.Length - 1;
}
else
{
nextPos = head - 1;
}
nextChar = reader.Read();
}
return false;
}
}
然后你可以像这样并行处理文件
var stringChars = searchString.ToCharArray();
if (Directory.EnumerateFiles(
"d:\\tes\\",
"*.txt",
SearchOption.AllDirectories)
.AsParallel()
.Any(file => FileContains(file, stringChars)))
{
MessageBox.Show("Found search string!");
}
答案 1 :(得分：2)
使用Directory.EnumerateFiles()和File.ReadLines() - 两者都提供延迟加载数据：
from file in Directory.EnumerateFiles(path)
from arr in File.ReadLines(file)
from str in arr
where str.Contains(pattern)
select new
{
FileName = file, // file containing matched string
Line = str // matched string
};
或
foreach (var file in Directory.EnumerateFiles(path).AsParallel())
{
try
{
foreach (var arr in File.ReadLines(file).AsParallel())
{
// one more try here?
foreach (var str in arr)
{
if (str.Contains(pattern))
{
yield return new
{
FileName = file, // file containing matched string
Line = str // matched string
};
}
}
}
}
catch (SecurityException)
{
// swallow or log
}
}
答案 2 :(得分：1)
这很有效。我在不到0.5毫秒的时间内搜索了超过230个文件的500个术语。这是非常记忆密集的;它将每个文件加载到内存中
public class FindInDirectory
{
public class Match
{
public string Pattern { get; set; }
public string Directory { get; set; }
public MatchCollection Matches { get; set; }
}
public static List<FindInDirectory.Match> Search(string directory, string searchPattern, List<string> patterns)
{
//find all file locations
IEnumerable<string> files = System.IO.Directory.EnumerateFiles(directory, searchPattern, System.IO.SearchOption.AllDirectories);
//load all text into memory for MULTI-PATERN
//this greatly increases speed, but it requires a ton of memory!
Dictionary<string, string> contents = files.ToDictionary(f => f, f => System.IO.File.ReadAllText(f));
List<FindInDirectory.Match> directoryMatches = new List<Match>();
foreach (string pattern in patterns)
{
directoryMatches.AddRange
(
contents.Select(c => new Match
{
Pattern = pattern,
Directory = c.Key,
Matches = Regex.Matches(c.Value, pattern, RegexOptions.IgnoreCase | RegexOptions.Multiline)
})
.Where(c => c.Matches.Count > 0)//switch to > 1 when program directory is same or child of search
);
};
return directoryMatches;
}
}
使用：
static void Main(string[] args)
{
List<string> patterns = new List<string>
{
"class",
"foreach",
"main",
};
string searchPattern = "*.cs";
string directory = "C:\\SearchDirectory";
DateTime start = DateTime.UtcNow;
FindInDirectory.Search(directory, searchPattern, patterns);
Console.WriteLine((DateTime.UtcNow - start).TotalMilliseconds);
Console.ReadLine();
}
答案 3 :(得分：0)
您可以使用Tasks.Dataflow创建“管道”（此.dll目前不是.NET 4.5的一部分，但您可以从here下载）以使用所有文件并搜索显式字符串。看一下这个Reference Implementation。