How to check if the location in table is accessible from SQL Query

EXEC sp_configure 'show advanced options', 1
go
reconfigure
go
EXEC sp_configure'xp_cmdshell', 1 
go
exec xp_cmdshell 'dir c:\'

if not exists(select * from tempdb.dbo.sysobjects
    where name like '#tmptable_%')
begin
    create table #tmptable (dirs varchar(255));
    insert into #tmptable(dirs)
    values('d:\tmp\'), ('d:\source');
    create table #restable (dir_list varchar(255));
end


declare @mydir sysname;
declare @cmd sysname;
declare dircursor cursor for select * from #tmptable;
open dircursor;
fetch next from dircursor into @mydir;
while @@FETCH_STATUS=0
begin
    set @cmd='dir '+@mydir+' /b';
    insert into #restable(dir_list) exec xp_cmdshell @cmd;
    if exists (select * from #restable where dir_list='File Not Found')
        print 'not a dir: '+@mydir;
    else
        print 'exists: '+@mydir;
    delete from #restable;
    fetch next from dircursor into @mydir;
end
close dircursor;
deallocate dircursor
go