我正在使用Popen在ssh上启动一个telnet进程,通过telnet发送命令并检查输出以监视telnet的状态。奇怪的是,我发现该代码在Python 3.2.3中运行正常,但在没有代码更改的情况下在Python 3.6.5中无法获取输出。
我尝试过:
- 刷新stdout - 在stdout.write后等待最多10秒 - 检查了stderr
我尝试过:
- 刷新stdout - 在stdout.write后等待最多10秒 - 检查了stderr
def nonblockingread(sout):
fd = output.fileno()
fl = fcntl.fcntl(fd, fcntl.F_GETFL)
try:
return sout.read()
except:
return ""
process = Popen(shlex.split("ssh anon@server \"telnet 0 2323\""), stdin=subprocess.PIPE, stdout=subprocess.PIPE, stderr=subprocess.PIPE)
print(nonblockingread(process.stdout)) # works for both versions
process.stdin.write(b"start service 4\n")
print(nonblockingread(process.stdout)) # works in 3.2 but not 3.6 (prints empty line)
print(process.stdout.readline()) # also prints empty line in 3.6