删除C/C++中的注释-有限状态机（C语言实现）

前段时间写了一个删除c/c++源程序中的注释的程序，结构比较复杂，现在考虑用有限状态机来解决。代码没有考虑字符串、嵌套下的情况，若要考虑，还需进行少许修改。代码如下

 

#include <stdio.h>enum {CODE,COMMENT1,//“/**/”型注释COMMENT2,//“//”型注释}g_state=CODE;enum Input{CH, //其他字符CH1, // "/*" or "*/"CH2,// "//"RT,// "/n"};Input alter(char ch, FILE *file){char temp;if(ch=='/'){temp = fgetc(file);if(temp=='/') return CH2;else if(temp=='*') return CH1;else {fseek(file, -1, 1);return CH;}}else if(ch=='*'){temp = fgetc(file);if(temp=='/') return CH1;else{fseek(file, -1, 1);return CH;}}else if(ch=='/n')return RT;else return CH;}int main(){ FILE *infile = fopen("infile.cpp", "r"); FILE *outfile = fopen("outfile.cpp", "w"); Input input; if(infile==NULL) { printf("cannot open infile!"); return -1; } char ch; ch = fgetc(infile); while(ch!=EOF) { input = alter(ch, infile); switch(g_state) { case CODE: if(input==CH || input==RT) fputc(ch, outfile); else if(input==CH1) g_state = COMMENT1; else if(input==CH2) g_state = COMMENT2; else ; break; case COMMENT1: if(input==CH1) g_state = CODE; break; case COMMENT2: if(input==RT) { fputc('/n', outfile); g_state = CODE; break; } } ch = fgetc(infile); } printf("complete!"); getchar(); fclose(infile); fclose(outfile); return 0;}