Untitled

%{
    int chars=0,words=0,lines=0;
    %}
    %%
    [^\t\n ]+ {words++; chars=chars+yyleng;}
    [ ]* {chars++;}
    [\n] {lines++; chars++;}
    %%
    int main(){
        yyin = fopen("input.txt","r"); yylex();
        fclose(yyin);
        printf("\nwords = %d",words); printf("\ncharacters = %d",chars); printf("\nlines = %d\n",lines); return 0;
    }