我們要測試幾種情況，將一些.c檔案裡的C語言註釋轉換成c++語言註釋。

commentconvert.h

#ifndef __COMMENTCONVERT_H__
#define __COMMENTCONVERT_H__

#include<stdio.h>
#include<stdlib.h>

enum State
{
	NUL_STATE,//無註釋狀態
	C_STATE,//C註釋狀態
	CPP_STATE,//C++註釋狀態
	END_STATE //結束狀態
};
void DoNulState(FILE *pfIn, FILE *pfOut, enum State *state);
void DoCState(FILE *pfIn, FILE *pfOut, enum State *state);
void DoCppState(FILE *pfIn, FILE *pfOut, enum State *state);
void commentconvert(FILE* pfIn, FILE* pfOut);
#endif //__COMMENTCONVERT_H__

 

test.c

#define _CRT_SECURE_NO_WARNINGS 1

#include"commentconvert.h"
void test()
{
	FILE* pfIn;
	FILE* pfOut;
	pfIn = fopen("Input.c", "r");
	if (pfIn == NULL)
	{
		perror("the file for read");
		exit(EXIT_FAILURE);
	}
	pfOut = fopen("Output.c", "w");
	if (pfOut == NULL)
	{
		perror("the file for read");
		fclose(pfIn);
		pfIn = NULL;
		exit(EXIT_FAILURE);
	}
	commentconvert(pfIn, pfOut);
	fclose(pfOut);
	pfOut = NULL;
}
int main()
{
	test();
	system("pause");
	return 0;
}
 

commentconvert.c

#define _CRT_SECURE_NO_WARNINGS 1

#include"commentconvert.h"
void DoNulState(FILE *pfIn, FILE *pfOut, enum State *state)
{
	int first = fgetc(pfIn);
	switch (first)
	{
	case '/':
	{
				int second = fgetc(pfIn);
				switch (second)
				{
				case '*':
				{
							fputc('/', pfOut);
							fputc('/', pfOut);
							*state = C_STATE;
				}
					break;
				case '/':
				{
							fputc(first, pfOut);
							fputc(second, pfOut);
							*state = CPP_STATE;
				}
					break;
				case EOF:
				{
							fputc(first, pfOut);
							*state = END_STATE;
				}
					break;
				default:
				{
						   fputc(first, pfOut);
						   fputc(second, pfOut);
				}
					break;
				}
	}
		break;
	case EOF:
		*state = END_STATE;
		break;
	default:
		fputc(first, pfOut);
		break;
	}
}
void DoCState(FILE *pfIn, FILE *pfOut, enum State *state)
{
	int first = fgetc(pfIn);
	switch (first)
	{
	case '*':
	{
				int second = fgetc(pfIn);
				switch (second)
				{
				case '/':
				{
							int third = fgetc(pfIn);
							switch (third)
							{
							case '\n':
								fputc('\n', pfOut);
								*state = NUL_STATE;
								break;
							case '/':
								fputc(first, pfOut);
								fputc(second, pfOut);
								fputc(third, pfOut);
								*state = C_STATE;
								break;
							default:
								fputc('\n', pfOut);
								fputc(third, pfOut);
								*state = NUL_STATE;
								break;
							}
				}
					//fputc('\n', pfOut);
					//*state = NUL_STATE;
					break;
				default:
					fputc(first, pfOut);
					ungetc(second, pfIn);
					break;
				}
	}
		break;
	case '\n':
	{
				 fputc('\n', pfOut);
				 fputc('/', pfOut);
				 fputc('/', pfOut);
				 *state = C_STATE;
	}
		break;
	case EOF:
		*state = END_STATE;
		break;
	default:
		fputc(first, pfOut);
		break;
	}
}
void DoCppState(FILE *pfIn, FILE *pfOut, enum State *state)
{
	int first = fgetc(pfIn);
	switch (first)
	{
	case '\n':
	{
				fputc('\n', pfOut);
				*state = NUL_STATE;
	}
		break;
	case EOF:
		*state = END_STATE;
		break;
	default:
		fputc(first, pfOut);
		break;
	}
}
void commentconvert(FILE* pfIn, FILE* pfOut)
{
	enum State state=NUL_STATE;
	while (state != END_STATE)
	{
		switch (state)
		{
		case NUL_STATE:
			DoNulState(pfIn, pfOut, &state);
			break;
		case C_STATE:
			DoCState(pfIn, pfOut, &state);
			break;
		case CPP_STATE:
			DoCppState(pfIn, pfOut, &state);
			break;
		default:

			break;
		}
	}
}
 

以下是此程式碼測試的幾種情況：