Linux 读取文件n行并删除方法

最近工作中读取对AC或者AP产生的Event的文件并发送ACS后删除已发送的内容，下次发送未发送event。产生的event存入event文件中，要对event.dat文件进行文件操作，以下是操作流程！

void ParseEvent(void)
{
	FILE *fp,*dfp;
	char cp[1024],dir[128],ddir[128];
	struct stat buf;

	memset(dir,0,sizeof(dir));
	memset(ddir,0,sizeof(ddir));
	sprintf(dir,"event.dat");

	sprintf(ddir,"event.dat.bak");
	if(!access(dir,F_OK)){
		fp = fopen(dir,"r+");
		dfp = fopen(ddir,"w+");
		if(fp && dfp)
		{
			while (fgets (cp, sizeof(cp), fp) != NULL)
			{
				// remove the line start with '#', ' ', '\n', '\0'
				if ( cp[0] == '#' || cp[0] == ' ' || cp[0] == '\n' || cp[0] == '\0' )
				{
					continue;
				}
				// read NUM_LINES lines from the file
				if( ++ec  < NUM_LINES)
				{			
					FireEvent(cp);
				}else{
					fprintf(dfp,"%s\n",cp);
				}
			}
			fclose(fp);
			fclose(dfp);
			// sync all the buffer or cache to the file system
			sync();
			// rename() if the file exist, the file will be replaced.
			rename(ddir,dir);
		}
	}
}