sed(1) -n '/\.ph\(p\|tml\)$/p'
stream editor for filtering and transforming text
-n, --quiet, --silent

       suppress automatic printing of pattern space
If no -e, --expression, -f, or --file option is given, then the first non-option argument is taken as the
sed script to interpret.  All remaining arguments are names  of  input  files;  if  no  input  files  are
specified, then the standard input is read.
source manpages: sed