去除注释

题目描述：

1. 将一个.c文件1复制到另一个文件2中，要求过滤掉文件1中的注释。

注释类型：以//开头或者/**/中的注释。用一个函数完成该功能。

基本要求：假设//或者/**/不会出现在printf语句中。

高级要求：要能处理printf中的//或者/**/

练习目的：练习文件的基本操作

//klkl//kk;;l/*l;;l*/

/*klklk/*k;k;l

lklkl*/

/*klklkl//klklkl*/

/*上述红色字体部分都是注释*/

main()

{

printf("here // should not be handled as comment");

printf("here /* .. */ should not be handled as comment");

}

状态转换图：

代码：

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
FILE * inputFile, *outputFile;
int curState = 0;
char curChar;
char commentBuffer[10]="";
int bufferSize = 0;

void handleCurChar()
{
    switch(curState)
    {
        case 0:
            if(curChar == '/')
            {
                commentBuffer[bufferSize] = curChar;
                commentBuffer[++bufferSize] = '\0';
            }
            else
            {
                fputc(curChar, outputFile);
            }
            break;
        case 1:
            if(curChar == '/' || curChar == '*')
            {
                commentBuffer[0] = '\0';
            }
            else
            {
                fputs(commentBuffer, outputFile);
                commentBuffer[0] = '\0';
                fputc(curChar, outputFile);
            }
            break;
        case 2:
            break;
        case 3:
            break;
        case 4:
            fputc(curChar, outputFile);
            break;
        case 5:
            break;
        case 6:
            if(curChar == '/')
            {
                commentBuffer[bufferSize] = curChar;
                commentBuffer[++ bufferSize] = '\0';
            }
            else
            {
                printf("%c", fputc(curChar, outputFile));
            }
            break;
    }
}
void changeState()
{
    switch(curState)
    {
        case 0:
            if(curChar == '/')
            {
                curState = 1;
            }
            else if(curChar == '"')
            {
                curState = 4;
            }
            else
            {
                curState = 6;
            }
            break;
        case 1:
            if(curChar == '/')
            {
                curState = 2;
            }
            else if(curChar == '*')
            {
                curState = 3;
            }
            else if(curChar == '"')
            {
                curState = 4;
            }
            else
            {
                curState = 6;
            }
            break;
        case 2:
            if(curChar == '\n')
            {
                curState = 6;
            }
            else
            {
                curState = 2;
            }
            break;
        case 3:
            if(curChar == '*')
            {
                curState = 5;
            }
            else
            {
                curState = 3;
            }
            break;
        case 4:
            if(curChar == '"')
            {
                curState = 6;
            }
            else
            {
                curState = 4;
            }
            break;
        case 5:
            if(curChar == '/')
            {
                curState = 6;
            }
            else
            {
                curState = 3;
            }
            break;
        case 6:
            if(curChar == '/')
            {
                curState = 1;
            }
            else if(curChar == '"')
            {
                curState = 4;
            }
            else
            {
                curState = 6;
            }
            break;
    }
}
void clearComments()
{
    while(!feof(inputFile))
    {
        curChar = fgetc(inputFile);
        handleCurChar();
        changeState();
    }
}
int main(void){
    printf("hello");
                              /*指向两个文件的指针*/
	if((inputFile=fopen("1.txt","r"))==NULL)             /*假如打不开的情况*/
	{
		printf("File could not be opened\n");
	}
	else if((outputFile=fopen("2.txt","w"))==NULL)
	{
		printf("File could not be opened\n");
	}
	else                                              /*打开之后引用函数*/
	{
		clearComments();
	}
	fclose(inputFile);                                   /*关闭文件*/
	fclose(outputFile);
	getchar();
	return 0;
}