FileSys::Write( const char *, int, Error * )

Attempt to write “len” bytes of data to the object referenced by the file handle (returned by the Open() method) from the buffer pointed to by “buf”.

Virtual?	Yes
Class	FileSys
Arguments	const char *buf	pointer to buffer containing data to be written
	int len	length of data to write
	Error *error	returned error status
Returns	void

Notes

The default implementation of Write() is called every time there is a need to write data to the file created by the Open() call.

Your implementation must correctly report any system errors that might occur during I/O.

Example

To use Write() to write an error to a log file:

StrBuf m;
m.Set( "Unknown user\r\n" );
FileSys *f = FileSys::Create( FST_ATEXT );
Error e;

f->Set( "C:\\logfile.txt" );
f->Open( FOM_WRITE, &e );
f->Write( m.Text(), m.Length(), &e );
f->Close( &e );

To reimplement Write() to report errors with Error::Sys() and provide debugging output:

void FileSysDemo::Write( const char *buf, int len, Error *e )
{
    int bytes;

    if ( ( bytes = write( fd, buf, len ) ) < 0 )
        e->Sys( "write", Name() );

    if ( DEBUG )
        printf( "debug (Write): %d bytes\n", bytes );
}