fgets显示文件行数

int main(int argc, const char *argv[])
{
	if(argc != 2)
	{
	  printf("input file wrror\n");
	  printf("wsage:./a.out dileName\n");
	  return -1;
	} 

	FILE *fp;
	if((fp=fopen(argv[1],"r"))==NULL)
	{
	    perror("fopen error");
		return -1;
	}

	char buf[5];
	int count = 0;
	
	while(fgets(buf,sizeof(buf),fp) != NULL)
	{
		if(buf[strlen(buf)-1] == '\n')
		{
		  count++;
		}
	}

	fclose(fp);
	printf("文件一共有%d行\n",count);
	return 0;
}

fgets和fputs实现拷贝文件内容

int main(int argc, const char *argv[])
{
	if(argc != 3)
	{
	    printf("input file error\n");
		printf("usage:./a.out srcfile dstfile\n");
	}

	FILE *srcfp;
	if((srcfp = fopen(argv[1],"r"))==NULL)
	{
	    perror("srclife open error");
		return -1;
	}

	FILE *dstfp;
	if((dstfp = fopen(argv[2],"w"))==NULL)
	{
	    perror("dstfile open error");
		return -1;
	}

	char buf[100];
	while(fgets(buf,100,srcfp) != NULL)
	{
	    fputs(buf,dstfp);
	}

	fclose(srcfp);
	fclose(dstfp);

	printf("拷贝成功\n");
	return 0;
}