How to read output from python 2.7 and Apache subprocess
I have an Apache web server and I created a python script to run a command. The command I'm running runs a ROS startup file that runs endlessly. I would like to read the output from a subprocess live and display it on a page. With my code so far, I could only draw the output to be printed after the process finished. I've tried all kinds of solutions from the internet but none of them work
command = "roslaunch package test.launch"
proc = subprocess.Popen(
command,
stdout=subprocess.PIPE,
stderr=subprocess.STDOUT,
env=env,
shell=True,
bufsize=1,
)
print "Content-type:text/html\r\n\r\n"
for line in iter(proc.stdout.readline, ''):
strLine = str(line).rstrip()
print(">>> " + strLine)
print("<br/>")
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The problem is that the output is roslaunch
buffered. subprocess
- not the best tool for processing the output in real time in such a situation, but there is a perfect tool for this task in the Python: pexpect
. The following snippet should do the trick:
import pexpect
command = "roslaunch package test.launch"
p = pexpect.spawn(command)
print "Content-type:text/html\r\n\r\n"
while not p.eof():
strLine = p.readline()
print(">>> " + strLine)
print("<br/>")
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