public static FileType DetectMimeType(this Stream stream)
{
var tmp = MimeTypes.AllTypes.Select(x => x.HeaderOffset + x.Header.Length).OrderByDescending(x => x)
.FirstOrDefault();
var data = new byte[tmp];
stream.Read(data, 0, data.Length);
stream.Position = 0;
IEnumerable <byte?> GetHeader(FileType t) => data
.Skip(t.HeaderOffset)
.Take(t.Header.Length)
.Cast <byte?>();
var comparer = new IgnoreNullComparer();
var result = MimeTypes.AllTypes
.OrderByDescending(t => t.Header.Length)
.FirstOrDefault(t => t.Header.SequenceEqual(GetHeader(t), comparer));
if (result == null)
{
return(null);
}
if (!result.Equals(MimeTypes.ZIP))
{
return(result);
}
return(CheckForMsOfficeTypes(stream) ?? MimeTypes.ZIP);
}
public static FileType DetectMimeType(this byte[] file)
{
IEnumerable <byte?> GetHeader(FileType t) => file
.Skip(t.HeaderOffset)
.Take(t.Header.Length)
.Cast <byte?>();
var comparer = new IgnoreNullComparer();
var result = MimeTypes.AllTypes
.FirstOrDefault(t => t.Header.SequenceEqual(GetHeader(t), comparer));
if (result == null)
{
return(null);
}
if (!result.Equals(MimeTypes.ZIP))
{
return(result);
}
using (var ms = new MemoryStream(file))
{
return(CheckForDocxAndXlsx(ms) ?? MimeTypes.ZIP);
}
}
public static FileType DetectMimeType(this byte[] file)
{
var comparer = new IgnoreNullComparer();
var result = MimeTypes.AllTypes
.OrderByDescending(t => t.Signatures.Length)
.ThenByDescending(t => t.Signatures.Sum(s => s.SignatureBytes.Length))
.FirstOrDefault(t => t.Signatures.All(s => s.SignatureBytes.SequenceEqual(GetSignature(file, s), comparer)));
if (result == null)
{
return(DefaultFallback);
}
if (result.Equals(MimeTypes.MCF))
{
return(CheckForMsOldOfficeTypes(file) ?? DefaultFallback);
}
if (!result.Equals(MimeTypes.ZIP))
{
return(result);
}
using (var ms = new MemoryStream(file))
{
return(CheckForMsOfficeTypes(ms) ?? MimeTypes.ZIP);
}
}
