PL/I

Hello2: proc options(main);
     put list ('Hello, world!');
end Hello2;

/* Read in a line, which contains a string,
/* and then print every subsequent line that contains that string. */

find_strings: procedure options (main);
   declare pattern character (100) varying;
   declare line character (100) varying;
   declare line_no fixed binary;

   on endfile (sysin) stop;

   get edit (pattern) (L);
   line_no = 1;
   do forever;
      get edit (line) (L);
      if index(line, pattern) > 0 then
         put skip list (line_no, line);
      line_no = line_no + 1;
   end;

end find_strings;