%{#include <string>#include <iostream>%}%%[/t ]+ /* white space */[a-zA-Z]+ { std::string Word(yytext); std::cout<<"word: "<<word<<std::endl; }[0-9]+ { std::string number(yytext); std::cout<<"number: "<<number<<std::endl; }.|/n {ECHO; /* normal default anyway */ }%%int main(){ std::cout<<"Lex and C++"<<std::endl; yylex(); return 0;}
運行
$ lex test.l $ gcc -o test lex.yy.c -lltest.l:3:10: fatal error: 'string' file not found#include <string> ^1 error generated.$ g++ -o test lex.yy.c -llclang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is dePRecated$ lslex.yy.c test test.l$ ./test Lex and C++the price is 100 yuan.word: theword: priceword: isnumber: 100word: yuan.^C$ cp lex.yy.c lex.yy.cpp$ g++ -o test lex.yy.cpp -ll$ ./test Lex and C++the price is 100 yuan.word: theword: priceword: isnumber: 100word: yuan.^C$
