如何解决Linux 中 Python 子进程之间的管道难点
以下脚本(应该从 p1 获取输出并将其通过管道传输到 p2,然后在终端中输出结果)似乎没有按预期工作。
代码如下:
#!/binr/bin/python
# Script to lauch mosquitto_sub to monitor a mqtt topic -- Syntax : mosk topic
import sys
import subprocess
total = len(sys.argv)
cmdargs = str(sys.argv)
print ("The total numbers of args passed to the script: %d " % total)
print ("Args list: %s " % cmdargs)
# Pharsing args one by one
print ("Script name: %s" % str(sys.argv[0]))
print ("First argument: %s" % str(sys.argv[1]))
path = str(sys.argv[1])
print (path)
p1 = subprocess.Popen(['mosquitto_sub','-h','192.168.1.100','-t',path,'-v'],shell=False,stdout=subprocess.PIPE)
p2 = subprocess.Popen(['ts'],stdin=p1.stdout,stdout=subprocess.PIPE)
for line in p2.stdout:
sys.stdout.write(line)
输入如下“./mosk2.py test/+”,在通过 mosquitto 发布相关主题的 MQTT 时,我从未在终端中得到预期的输出
解决方法
已解决 - 我最终巧妙地解决了问题(作弊),如下所示:
cmd = "mosquitto_sub -h 192.168.1.100 -v -t " + topic + " | ts"
print "The command which was executed is : ",cmd
def run_command(command):
process = subprocess.Popen(command,stdout=subprocess.PIPE,shell=True)
while True:
output = process.stdout.readline()
if output == '' and process.poll() is not None:
break
if output:
print output.strip()
rc = process.poll()
return rc
run_command(cmd) #This is the lauch of the actual command
版权声明:本文内容由互联网用户自发贡献,该文观点与技术仅代表作者本人。本站仅提供信息存储空间服务,不拥有所有权,不承担相关法律责任。如发现本站有涉嫌侵权/违法违规的内容, 请发送邮件至 dio@foxmail.com 举报,一经查实,本站将立刻删除。