.NET Framework System.IO.File class Enumerate files older than a specified amount
Example
This snippet is an helper function to enumerate all files older than a specified age, it's useful - for example - when you have to delete old log files or old cached data.
static IEnumerable<string> EnumerateAllFilesOlderThan(
TimeSpan maximumAge,
string path,
string searchPattern = "*.*",
SearchOption options = SearchOption.TopDirectoryOnly)
{
DateTime oldestWriteTime = DateTime.Now - maximumAge;
return Directory.EnumerateFiles(path, searchPattern, options)
.Where(x => Directory.GetLastWriteTime(x) < oldestWriteTime);
}
Used like this:
var oldFiles = EnumerateAllFilesOlderThan(TimeSpan.FromDays(7), @"c:\log", "*.log");
Few things to note:
- Search is performed using
Directory.EnumerateFiles()instead ofDirectory.GetFiles(). Enumeration is alive then you won't need to wait until all file system entries have been fetched. - We're checking for last write time but you may use creation time or last access time (for example to delete unused cached files, note that access time may be disabled).
- Granularity isn't uniform for all those properties (write time, access time, creation time), check MSDN for details about this.
