“`flex
%{
#include
%}

%%

int|integers { printf(“Keyword: int\n”); }
float|floating { printf(“Keyword: float\n”); }
if { printf(“Keyword: if\n”); }
then { printf(“Keyword: then\n”); }
else { printf(“Keyword: else\n”); }
for { printf(“Keyword: for\n”); }
print£ { printf(“Keyword: print£\n”); }
switch { printf(“Keyword: switch\n”); }
case { printf(“Keyword: case\n”); }
return { printf(“Keyword: return\n”); }
[0-9]+ { printf(“Integer: %s\n”, yytext); }
[0-9]+”.”[0-9]+ { printf(“Float: %s\n”, yytext); }
. { /* Ignore other characters */ }

%%

int main() {
yylex();
return 0;
}
“`