问题
When I run this command which makes the ble device scanning for just 5 seconds only:
$ sudo timeout 5s hcitool -i hci0 lescan
the output is shown in the terminal screen.
But when I redirect the output to a file to save the addresses of the advertising devices, every time I run the command I find the file is empty and the output isn't visible in the terminal nor in the file.
The command I used:
$ sudo timeout 5s hcitool -i hci0 lescan > file.txt
What do I have to do in order to make hcitool correctly redirect its ouput to the file?
回答1:
timeout by default sends a SIGTERM to the program. Looks like hcitool doesn't handle that gracefully. Instead use SIGINT (equivalent to ctrl-c).
sudo timeout -s SIGINT 5s hcitool -i hci0 lescan > file.txt
来源：https://stackoverflow.com/questions/32300008/scan-bluetooth-low-energy-using-hcitool