泛舟湖上清波郎朗
到append文件使用 >>echo "hello world" >> read.txt cat read.txt echo "hello siva" >> read.txt cat read.txt那么输出应该是hello world # from 1st echo commandhello world # from 2nd echo commandhello siva到overwrite文件使用 >echo "hello tom" > read.txtcat read.txt 那么输出就是hello tom