C소수 중에서 주석 // 을 /* ~ */ 로 변경하는 쉬운 방법

#include <stdio.h>
 
int main(int argc, char *argv[])
{
	FILE *in;
	FILE *out;
	char backup[300];
	char buff[5000];
	char *s;
	char *p;
	char *t;
	char *q;
	int i,len;
	int star = 0;
 
	if(argc != 2)
	{
		printf("error argument\n");
		return 0;
	}
 
 
	// file backup
	if((in=fopen(argv[1],"rb"))==NULL)
	{
		printf("error read file open\n");
		return 0;
	}
 
	sprintf(backup,"%s.bak",argv[1]);
	if((out=fopen(backup,"wb"))==NULL)
	{
		printf("error write file open\n");
		fclose(in);
		return 0;
	}
 
	while(fgets(buff,sizeof(buff), in) != NULL)	fputs(buff,out);
	fclose(out);
	fclose(in);
 
 
	// 작업시작
	if((in=fopen(backup,"rb"))==NULL)
	{
		printf("error read file open\n");
		return 0;
	}
 
	if((out=fopen(argv[1],"wb"))==NULL)
	{
		printf("error write file open\n");
		fclose(in);
		return 0;
	}
 
 
 
 
 
	while(fgets(buff,sizeof(buff),in) != NULL)
	{
		s = buff;
 
cmt :
 
		// "*/" 처리
		if(star == 1)
		{
			len = strlen(s);
			p = strstr(s,"*/");
			if(!p)
			{
				fputs(s,out);
				continue;				
			}
			for(i=0 ; i<len ; i++)
			{
				fputc((int)(*(s+i)), out);
				if(p == s+i)
				{
					fputc((int)(*(s+i+1)), out);
					s = s+i+2;
					star = 0;
					break;
				}
			}
		}
 
		// "/*" 처리
		p = strstr(s,"//");
		t = strstr(s,"/*");
 
		if((p && t&& p>t) || t && !p )
		{
			star = 1;
			len = strlen(s);
			q = strstr(t,"*/");
			if(q)
			{
				for(i=0 ; i<len ; i++)
				{
					fputc((int)(*(s+i)), out);
					if(q == s+i)
					{
						fputc((int)(*(s+i+1)), out);
						s = s+i+2;
						goto cmt;
					}
 
				}	
			}
 
			fputs(s,out);
			continue;
		}
 
		// "//"처리
		if(!p)
		{
			fputs(s,out);
			continue;
		}
		len = strlen(s);
		for(i=0 ; i<len ; i++)
		{
			if(p == s+i)	fputs("/*", out);
			if(*(s+i)== 0x0a || *(s+i) == 0x0d)
			{
				fputs("*/\n", out);
				continue;
			}
			fputc((int)(*(s+i)), out);
		}
	}
 
	fclose(out);
	fclose(in);
 
	printf("ok :: %s\n", argv[1]);
 
	return 0;
}