| static private Read ( SafeFileHandle fd, byte buffer, int offset, int count ) : int | ||
| fd | SafeFileHandle | The file descriptor. |
| buffer | byte | The buffer to read into. |
| offset | int | The offset at which to start writing into the buffer. |
| count | int | The maximum number of bytes to read. |
| return | int | |
/// <summary>Read the database for the specified terminal from the specified directory.</summary>
/// <param name="term">The identifier for the terminal.</param>
/// <param name="directoryPath">The path to the directory containing terminfo database files.</param>
/// <returns>The database, or null if it could not be found.</returns>
private static Database?ReadDatabase(string?term, string?directoryPath)
{
if (string.IsNullOrEmpty(term) || string.IsNullOrEmpty(directoryPath))
{
return(null);
}
Span <char> stackBuffer = stackalloc char[256];
SafeFileHandle?fd;
if (!TryOpen(string.Create(null, stackBuffer, $"{directoryPath}/{term[0]}/{term}"), out fd) && // /directory/termFirstLetter/term (Linux)
!TryOpen(string.Create(null, stackBuffer, $"{directoryPath}/{(int)term[0]:X}/{term}"), out fd)) // /directory/termFirstLetterAsHex/term (Mac)
{
return(null);
}
using (fd)
{
// Read in all of the terminfo data
long termInfoLength = Interop.CheckIo(Interop.Sys.LSeek(fd, 0, Interop.Sys.SeekWhence.SEEK_END)); // jump to the end to get the file length
Interop.CheckIo(Interop.Sys.LSeek(fd, 0, Interop.Sys.SeekWhence.SEEK_SET)); // reset back to beginning
const int MaxTermInfoLength = 4096; // according to the term and tic man pages, 4096 is the terminfo file size max
const int HeaderLength = 12;
if (termInfoLength <= HeaderLength || termInfoLength > MaxTermInfoLength)
{
throw new InvalidOperationException(SR.IO_TermInfoInvalid);
}
byte[] data = new byte[(int)termInfoLength];
if (ConsolePal.Read(fd, data) != data.Length)
{
throw new InvalidOperationException(SR.IO_TermInfoInvalid);
}
// Create the database from the data
return(new Database(term, data));
}
}
/// <summary>Read the database for the specified terminal from the specified directory.</summary>
/// <param name="term">The identifier for the terminal.</param>
/// <param name="directoryPath">The path to the directory containing terminfo database files.</param>
/// <returns>The database, or null if it could not be found.</returns>
private static Database ReadDatabase(string term, string directoryPath)
{
if (string.IsNullOrEmpty(term) || string.IsNullOrEmpty(directoryPath))
{
return(null);
}
SafeFileHandle fd;
if (!TryOpen(directoryPath + "/" + term[0].ToString() + "/" + term, out fd) && // /directory/termFirstLetter/term (Linux)
!TryOpen(directoryPath + "/" + ((int)term[0]).ToString("X") + "/" + term, out fd)) // /directory/termFirstLetterAsHex/term (Mac)
{
return(null);
}
using (fd)
{
// Read in all of the terminfo data
long termInfoLength = Interop.CheckIo(Interop.Sys.LSeek(fd, 0, Interop.Sys.SeekWhence.SEEK_END)); // jump to the end to get the file length
Interop.CheckIo(Interop.Sys.LSeek(fd, 0, Interop.Sys.SeekWhence.SEEK_SET)); // reset back to beginning
const int MaxTermInfoLength = 4096; // according to the term and tic man pages, 4096 is the terminfo file size max
const int HeaderLength = 12;
if (termInfoLength <= HeaderLength || termInfoLength > MaxTermInfoLength)
{
throw new InvalidOperationException(SR.IO_TermInfoInvalid);
}
int fileLen = (int)termInfoLength;
byte[] data = new byte[fileLen];
if (ConsolePal.Read(fd, data, 0, fileLen) != fileLen)
{
throw new InvalidOperationException(SR.IO_TermInfoInvalid);
}
// Create the database from the data
return(new Database(term, data));
}
}
public override int Read(byte[] buffer, int offset, int count)
{
ValidateRead(buffer, offset, count);
return(ConsolePal.Read(_handle, buffer, offset, count));
}