def capture_subprocess(cmd, encoding='UTF-8', **popen_kwargs):
"""Run a command, showing its usual outputs in real time,
and return its stdout, stderr output as strings.
No temporary files are used.
"""
stdout = Pty() # libc uses full buffering for stdout if it doesn't see a tty
stderr = Pipe()
# deadlocks occur if we have any write-end of a pipe open more than once
# best practice: close any used write pipes just after spawn
outputter = Popen(
cmd,
stdout=stdout.write,
stderr=stderr.write,
**popen_kwargs
)
stdout.readonly() # deadlock otherwise
stderr.readonly() # deadlock otherwise
# start one tee each on the original stdout and stderr
# writing each to three places:
# 1. the original destination
# 2. a pipe just for that one stream
stdout_tee = Tee(stdout.read, STDOUT)
stderr_tee = Tee(stderr.read, STDERR)
# clean up left-over processes and pipes:
exit_code = outputter.wait()
result = (stdout_tee.join(), stderr_tee.join())
if encoding is not None:
result = tuple(
bytestring.decode(encoding)
for bytestring in result
)
if exit_code == 0:
return result
else:
error = CalledProcessError(exit_code, cmd)
error.result = result
raise error
def capture_subprocess(cmd, encoding='UTF-8', **popen_kwargs):
"""Run a command, showing its usual outputs in real time,
and return its stdout, stderr output as strings.
No temporary files are used.
"""
stdout = Pty(
) # libc uses full buffering for stdout if it doesn't see a tty
stderr = Pipe()
# deadlocks occur if we have any write-end of a pipe open more than once
# best practice: close any used write pipes just after spawn
outputter = Popen(cmd,
stdout=stdout.write,
stderr=stderr.write,
**popen_kwargs)
stdout.readonly() # deadlock otherwise
stderr.readonly() # deadlock otherwise
# start one tee each on the original stdout and stderr
# writing each to three places:
# 1. the original destination
# 2. a pipe just for that one stream
stdout_tee = Tee(stdout.read, STDOUT)
stderr_tee = Tee(stderr.read, STDERR)
# clean up left-over processes and pipes:
exit_code = outputter.wait()
result = (stdout_tee.join(), stderr_tee.join())
if encoding is not None:
result = tuple(bytestring.decode(encoding) for bytestring in result)
if exit_code == 0:
return result
else:
error = CalledProcessError(exit_code, cmd)
error.result = result
raise error
