Add your all file in xampp htdocs folder
on browser put this -
localhost/filename.html
if your created your own folder in htdocs folder then-
localhost/foldername/filename.html
Never forget to start apache and mysql on xampp control panel
Window -
flex program_name.l
gcc lex.yy.c
./a.exe
Linux -
lex program_name.l
cc lex.yy.c -ll
./a.out
if program containt .y file-
lex program_name.l
yacc -d program_name.y
cc lex.yy.c y.tab.c -ll
./a.out