use CGI qw(:standard); use POSIX qw(strftime); print header( # date in the past -expires => 'Sat, 26 Jul 1997 05:00:00 GMT', # always modified -Last_Modified => strftime('%a, %d %b %Y %H:%M:%S GMT', gmtime), # HTTP/1.0 -Pragma => 'no-cache', # HTTP/1.1 + IE-specific (pre|post)-check -Cache_Control => join(', ', qw( private no-cache no-store must-revalidate max-age=0 pre-check=0 post-check=0 )), );