def system(self, cmd):
"""Execute a command in a subshell.
Parameters
----------
cmd : str
A command to be executed in the system shell.
Returns
-------
int : child's exitstatus
"""
# Get likely encoding for the output.
enc = DEFAULT_ENCODING
# Patterns to match on the output, for pexpect. We read input and
# allow either a short timeout or EOF
patterns = [pexpect.TIMEOUT, pexpect.EOF]
# the index of the EOF pattern in the list.
# even though we know it's 1, this call means we don't have to worry if
# we change the above list, and forget to change this value:
EOF_index = patterns.index(pexpect.EOF)
# The size of the output stored so far in the process output buffer.
# Since pexpect only appends to this buffer, each time we print we
# record how far we've printed, so that next time we only print *new*
# content from the buffer.
out_size = 0
try:
# Since we're not really searching the buffer for text patterns, we
# can set pexpect's search window to be tiny and it won't matter.
# We only search for the 'patterns' timeout or EOF, which aren't in
# the text itself.
#child = pexpect.spawn(pcmd, searchwindowsize=1)
if hasattr(pexpect, 'spawnb'):
child = pexpect.spawnb(self.sh, args=['-c', cmd]) # Pexpect-U
else:
child = pexpect.spawn(self.sh, args=['-c', cmd]) # Vanilla Pexpect
flush = sys.stdout.flush
while True:
# res is the index of the pattern that caused the match, so we
# know whether we've finished (if we matched EOF) or not
res_idx = child.expect_list(patterns, self.read_timeout)
print(child.before[out_size:].decode(enc, 'replace'), end='')
flush()
if res_idx==EOF_index:
break
# Update the pointer to what we've already printed
out_size = len(child.before)
except KeyboardInterrupt:
# We need to send ^C to the process. The ascii code for '^C' is 3
# (the character is known as ETX for 'End of Text', see
# curses.ascii.ETX).
child.sendline(chr(3))
# Read and print any more output the program might produce on its
# way out.
try:
out_size = len(child.before)
child.expect_list(patterns, self.terminate_timeout)
print(child.before[out_size:].decode(enc, 'replace'), end='')
sys.stdout.flush()
except KeyboardInterrupt:
# Impatient users tend to type it multiple times
pass
finally:
# Ensure the subprocess really is terminated
child.terminate(force=True)
# add isalive check, to ensure exitstatus is set:
child.isalive()
return child.exitstatus
def system(self, cmd):
"""Execute a command in a subshell.
Parameters
----------
cmd : str
A command to be executed in the system shell.
Returns
-------
int : child's exitstatus
"""
# Get likely encoding for the output.
enc = text.getdefaultencoding()
# Patterns to match on the output, for pexpect. We read input and
# allow either a short timeout or EOF
patterns = [pexpect.TIMEOUT, pexpect.EOF]
# the index of the EOF pattern in the list.
# even though we know it's 1, this call means we don't have to worry if
# we change the above list, and forget to change this value:
EOF_index = patterns.index(pexpect.EOF)
# The size of the output stored so far in the process output buffer.
# Since pexpect only appends to this buffer, each time we print we
# record how far we've printed, so that next time we only print *new*
# content from the buffer.
out_size = 0
try:
# Since we're not really searching the buffer for text patterns, we
# can set pexpect's search window to be tiny and it won't matter.
# We only search for the 'patterns' timeout or EOF, which aren't in
# the text itself.
#child = pexpect.spawn(pcmd, searchwindowsize=1)
if hasattr(pexpect, 'spawnb'):
child = pexpect.spawnb(self.sh, args=['-c', cmd]) # Pexpect-U
else:
child = pexpect.spawn(self.sh, args=['-c',
cmd]) # Vanilla Pexpect
flush = sys.stdout.flush
while True:
# res is the index of the pattern that caused the match, so we
# know whether we've finished (if we matched EOF) or not
res_idx = child.expect_list(patterns, self.read_timeout)
print(child.before[out_size:].decode(enc, 'replace'), end='')
flush()
if res_idx == EOF_index:
break
# Update the pointer to what we've already printed
out_size = len(child.before)
except KeyboardInterrupt:
# We need to send ^C to the process. The ascii code for '^C' is 3
# (the character is known as ETX for 'End of Text', see
# curses.ascii.ETX).
child.sendline(chr(3))
# Read and print any more output the program might produce on its
# way out.
try:
out_size = len(child.before)
child.expect_list(patterns, self.terminate_timeout)
print(child.before[out_size:].decode(enc, 'replace'), end='')
sys.stdout.flush()
except KeyboardInterrupt:
# Impatient users tend to type it multiple times
pass
finally:
# Ensure the subprocess really is terminated
child.terminate(force=True)
# add isalive check, to ensure exitstatus is set:
child.isalive()
return child.exitstatus