@julyclyde
我确认了一下，Unix socket 确实是不能直接作为普通文件 open 啊
```
~/testsocket $ python ../s.py &
[1] 23401
~/testsocket $ ls -alh
total 7.0K
drwx------ 2 root root 3.5K Oct 29 14:17 .
drwx------ 9 root root 3.5K Oct 29 14:16 ..
srwx------ 1 root root 0 Oct 29 14:17 socket
~/testsocket $ echo 123 > socket
bash: socket: No such device or address
~/testsocket $ echo 123 > ./socket
bash: ./socket: No such device or address
~/testsocket $ echo 123 | tee socket
tee: socket: No such device or address
123
~/testsocket $ cat socket
cat: socket: No such device or address
```