swapon -s will display all used swap areas, their type, size, usage, and priority.

swapon的命令-s显示所有已用交换区，它们的类型、大小、使用和优先级。

youdao

swapon (and its sister swapoff) is used to start swap on files/devices, and display status of currently used swap areas.

swapon(它的同类swapoff)用于开启文件系统/设备上的交换分区，显示目前使用交换区的状态。

youdao

Swap files used in this way are never generally a long-term solution to the problem for swap space.

以这种方式使用的交换文件通常决不是针对交换空间问题的长期解决方案。

youdao

Swap lines used to be used to provide dollars for foreign central banks to use to support their currencies in foreign exchange markets.

FORBES: The Fed's Balance Sheet

Such agreements allow central banks to swap currencies and can be used by firms to settle trade in local currencies rather than in US dollars, as happens now, since China's currency is not fully convertible to other currencies.

BBC: UK and China poised for currency swap deal

This hardware was used to build a simulated aircraft that ran many of the systems found on commercial aircraft and could swap data via radio with the air traffic and navigation systems used in the real world.

BBC: Hacker targets flight deck computer systems