Quite often, I output information through PRINT command. It works well only when message is shorter than 8000 bytes. When the message is greater than 8000 bytes, extra-characters will be removed. the simplest way to overcome this is to make a loop and print 8000 characters at a time

declare @line nvarchar(max) = Replicate(cast('0123456789' as varchar(max)), 800)+'abc
'
select @line = replicate(@line, 3)
declare @pos int = 1
while @pos <= len(@line)
begin
print substring(@line, @pos, 8000)
select @pos = @pos + 8000
end
/*
012345678901234567890....
abc
012345678901234567890....
6789abc
012345678901234567890....
23456789abc
*/

It seems good until I look at the line 12, 14, 16 above. what I really want to see is the first line contains numbers and the second line are letters, then the third line are numbers and fourth line are letters. Here is the procedure to display them correctly

create procedure PrintString (@str varchar(max))
as
begin
declare @line varchar(max), @StartLocation int, @Length int, @TotalLength int, @Current int
select @StartLocation = 1, @TotalLength = datalength(@str), @Current = 1, @Length = 0
declare @PrintLine nvarchar(max) =
'declare @pos int = 1
while @pos <= len(@line)
begin
print substring(@line, @pos, 8000)
select @pos = @pos + 8000
end'
while @Current <= @TotalLength
begin
if(substring(@str, @Current, 2) in( char(0x0d) + char(0x0a), char(0x0a) + char(0x0d)))
begin
if @Length <= 0
print ''
else
begin -- line
select @line = substring(@str, @StartLocation, @Length)
exec sp_executesql @PrintLine, N'@Line varchar(max)' , @line
end
select @StartLocation = @Current + 2, @Current = @Current + 2, @Length = 0
continue;
end
else if (substring(@str, @Current, 1) in(char(0x0d) , char(0x0a)))
begin
if @Length <= 0
print ''
else
begin
select @line = substring(@str, @StartLocation, @Length)
exec sp_executesql @PrintLine, N'@Line varchar(max)' , @line
end
select @StartLocation = @Current + 1, @Current = @Current + 1, @Length = 0
continue;
end
select @Current = @Current + 1, @Length = @Length + 1
end
if(@StartLocation <= datalength(@str))
print substring(@str, @StartLocation, datalength(@str))
end
go
declare @str nvarchar(max) = Replicate(cast('0123456789' as varchar(max)), 800)+'abc
'
select @str = replicate(@str, 3)
exec PrintString @str
/*
01234567890...
abc
01234567890...
abc
01234567890...
abc
*/

Everything looks good now.