txt文件格式是这样：
StartLoft
StartCurve
48.080990338 -13.719269957 -27.057190581
48.092208870 -13.679892032 -27.092132636
48.104499723 -13.636609050 -27.120879916
48.117735369 -13.589832336 -27.142704970
48.134686891 -13.529668065 -27.158733442
EndCurve
StartCurve
48.251861561 13.105642138 25.599082613
48.255634126 13.091744541 25.603722117
48.259503396 13.077474218 25.606634001
48.263434891 13.062957267 25.607440615
48.267413133 13.048250054 25.605574332
EndCurve
EndLoft
End
要求从StartLoft开始到End结束，把每段StartCurve和EndCurve中的数据输出为一个txt
还是没找到换行的写法