我使用以下方法创建了一个文件：
printf 'this is \n not is \n is is \n this biz' > file2
当我尝试删除所有 \n(newline) 时，它只会删除 sed 自己插入的数字的换行符
sed '=' file2 | sed 'N; s/\n/ /'
输出是：
1 this is
2 not is
3 is is
4 this biz
而不是我所期望的：
1 this is 2 not is 3 is is 4 this biz
我搞不清楚了。