I would like to know when the user from a command line presses control-c so I can save some stuff.
How do I do this? I've looked but haven't really seen anything.
Note: I'm somewhat familiar with lua, but I'm no expert. I mostly use lua to use the library Torch (http://torch.ch/)
Implementing a SIGINT
handler is straightforward using the excellent luaposix library:
local signal = require("posix.signal")
signal.signal(signal.SIGINT, function(signum)
io.write("\n")
-- put code to save some stuff here
os.exit(128 + signum)
end)
Refer to the posix.signal module's API documentation for more information.
windows : SetConsoleCtrlHandler
There are two behaviors of the signal which are undesirable, which will cause complexities in the code.
- Program termination
- Broken IO
The first behavior can be caught and remembered in a C program by using SetConsoleCtrlHandler/signal. This will allow your function to be called, and you can remember that the system needs to shutdown. Then at some point in the lua code you see it has happened (call to check), and perform your tidy up and shutdown.
The second behavior, is that a blocking operation (read/write) will be cancelled by the signal, and the operation will be unfinished. That would need to be checked at each IO event, and then re-started, or cancelled as appropriate.
There exists io libraries that support this. I know zmq and libuv
Libuv example with lluv binding - https://github.com/moteus/lua-lluv/blob/master/examples/sig.lua
ZeroMQ return EINTR from poll function when user press Ctrl-C
But I do not handle thi byself
require('sys')
sys.catch_ctrl_c()
I use this to catch the exit from cli.
来源:https://stackoverflow.com/questions/32337591/how-catch-ctrl-c-in-lua-when-ctrl-c-is-sent-via-the-command-line