python script for RaspberryPi to connect wifi automatically
Question:
I want to operate a WiFi dongle with RaspberryPi, (it’s like a CPU without built-in WiFi). I need to write a python script which automatically scan for WiFi networks and a connection need to be automatically established with known SSID and password.
This mean that I need to provide the password for the WiFi network from a file, and the
remaining thing is to do the scanning and connecting automatically.
I read a file from the Web which contains WiFi SSID name and password.
I need to write a script which scan and list current networds and match it to the SSID from the file and further to automatically create the connection to this known network.
RaspberryPi OS: Rasbian
Answers:
wifi is a python library for scanning and connecting to wifi networks on linux. You can use it to scan and connect to wireless networks.
It doesn’t have any built-in support for connecting automatically to a network, but you could easily write a script to do that. Here’s an example of a basic idea for how to do this.
#!/usr/bin/python
from __future__ import print_function
from wifi import Cell, Scheme
# get all cells from the air
ssids = [cell.ssid for cell in Cell.all('wlan0')]
schemes = list(Scheme.all())
for scheme in schemes:
ssid = scheme.options.get('wpa-ssid', scheme.options.get('wireless-essid'))
if ssid in ssids:
print('Connecting to %s' % ssid)
scheme.activate()
break
I just wrote it and it seems to work. Just so you know, I wrote the wifi library. If you want me to add this feature to that library, I could.
This is a monkey patch of rockymeza’s answer above, so that the Scheme will use the /etc/wpa_supplicant/wpa_supplicant.conf file instead of the /etc/network/interfaces file. I couldn’t get his Scheme class to work on my pi3s as it seems like the Schemes just adds iface wlan0-SSIDname for each network to the /etc/network/interfaces file, and there is no mapping or anything to tell it that ifup wlan0-SSIDname is associated with ‘wlan0’.
import re
from wifi import Cell, Scheme
import wifi.subprocess_compat as subprocess
from wifi.utils import ensure_file_exists
class SchemeWPA(Scheme):
interfaces = "/etc/wpa_supplicant/wpa_supplicant.conf"
def __init__(self, interface, name, options=None):
self.interface = interface
self.name = name
self.options = options or {}
def __str__(self):
"""
Returns the representation of a scheme that you would need
in the /etc/wpa_supplicant/wpa_supplicant.conf file.
"""
options = ''.join("n {k}="{v}"".format(k=k, v=v) for k, v in self.options.items())
return "network={" + options + 'n}n'
def __repr__(self):
return 'Scheme(interface={interface!r}, name={name!r}, options={options!r}'.format(**vars(self))
def save(self):
"""
Writes the configuration to the :attr:`interfaces` file.
"""
if not self.find(self.interface, self.name):
with open(self.interfaces, 'a') as f:
f.write('n')
f.write(str(self))
@classmethod
def all(cls):
"""
Returns an generator of saved schemes.
"""
ensure_file_exists(cls.interfaces)
with open(cls.interfaces, 'r') as f:
return extract_schemes(f.read(), scheme_class=cls)
def activate(self):
"""
Connects to the network as configured in this scheme.
"""
subprocess.check_output(['/sbin/ifdown', self.interface], stderr=subprocess.STDOUT)
ifup_output = subprocess.check_output(['/sbin/ifup', self.interface] , stderr=subprocess.STDOUT)
ifup_output = ifup_output.decode('utf-8')
return self.parse_ifup_output(ifup_output)
def delete(self):
"""
Deletes the configuration from the /etc/wpa_supplicant/wpa_supplicant.conf file.
"""
content = ''
with open(self.interfaces, 'r') as f:
lines=f.read().splitlines()
while lines:
line=lines.pop(0)
if line.startswith('#') or not line:
content+=line+"n"
continue
match = scheme_re.match(line)
if match:
options = {}
ssid=None
content2=line+"n"
while lines and lines[0].startswith(' '):
line=lines.pop(0)
content2+=line+"n"
key, value = re.sub(r's{2,}', ' ', line.strip()).split('=', 1)
#remove any surrounding quotes on value
if value.startswith('"') and value.endswith('"'):
value = value[1:-1]
#store key, value
options[key] = value
#check for ssid (scheme name)
if key=="ssid":
ssid=value
#get closing brace
line=lines.pop(0)
content2+=line+"n"
#exit if the ssid was not found so just add to content
if not ssid:
content+=content2
continue
#if this isn't the ssid then just add to content
if ssid!=self.name:
content+=content2
else:
#no match so add content
content+=line+"n"
continue
#Write the new content
with open(self.interfaces, 'w') as f:
f.write(content)
scheme_re = re.compile(r'network={s?')
#override extract schemes
def extract_schemes(interfaces, scheme_class=SchemeWPA):
lines = interfaces.splitlines()
while lines:
line = lines.pop(0)
if line.startswith('#') or not line:
continue
match = scheme_re.match(line)
if match:
options = {}
interface="wlan0"
ssid=None
while lines and lines[0].startswith(' '):
key, value = re.sub(r's{2,}', ' ', lines.pop(0).strip()).split('=', 1)
#remove any surrounding quotes on value
if value.startswith('"') and value.endswith('"'):
value = value[1:-1]
#store key, value
options[key] = value
#check for ssid (scheme name)
if key=="ssid":
ssid=value
#exit if the ssid was not found
if ssid is None:
continue
#create a new class with this info
scheme = scheme_class(interface, ssid, options)
yield scheme
To create the scheme, just do this:
scheme=SchemeWPA('wlan0',cell.ssid,{"ssid":cell.ssid,"psk":"yourpassword"})
Your /etc/network/interfaces file should look like this, or similar:
# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
iface eth0 inet manual
allow-hotplug wlan0
iface wlan0 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp
allow-hotplug wlan1
iface wlan1 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
Thank you all for your answers i made simple solution like below
def wifiscan():
allSSID = Cell.all('wlan0')
print allSSID # prints all available WIFI SSIDs
myssid= 'Cell(ssid=vivekHome)' # vivekHome is my wifi name
for i in range(len(allSSID )):
if str(allSSID [i]) == myssid:
a = i
myssidA = allSSID [a]
print b
break
else:
print "getout"
# Creating Scheme with my SSID.
myssid= Scheme.for_cell('wlan0', 'home', myssidA, 'vivek1234') # vive1234 is the password to my wifi myssidA is the wifi name
print myssid
myssid.save()
myssid.activate()
wifiscan()
You can use the natively available network manager cli package (nmcli):
import subprocess
def what_wifi():
process = subprocess.run(['nmcli', '-t', '-f', 'ACTIVE,SSID', 'dev', 'wifi'], stdout=subprocess.PIPE)
if process.returncode == 0:
return process.stdout.decode('utf-8').strip().split(':')[1]
else:
return ''
def is_connected_to(ssid: str):
return what_wifi() == ssid
def scan_wifi():
process = subprocess.run(['nmcli', '-t', '-f', 'SSID,SECURITY,SIGNAL', 'dev', 'wifi'], stdout=subprocess.PIPE)
if process.returncode == 0:
return process.stdout.decode('utf-8').strip().split('n')
else:
return []
def is_wifi_available(ssid: str):
return ssid in [x.split(':')[0] for x in scan_wifi()]
def connect_to(ssid: str, password: str):
if not is_wifi_available(ssid):
return False
subprocess.call(['nmcli', 'd', 'wifi', 'connect', ssid, 'password', password])
return is_connected_to(ssid)
def connect_to_saved(ssid: str):
if not is_wifi_available(ssid):
return False
subprocess.call(['nmcli', 'c', 'up', ssid])
return is_connected_to(ssid)
Connect to a saved network:
connect_to_saved('my_wifi')
Otherwise, connect to a network with ssid and password:
connect_to('my_wifi', 'my_password')
I want to operate a WiFi dongle with RaspberryPi, (it’s like a CPU without built-in WiFi). I need to write a python script which automatically scan for WiFi networks and a connection need to be automatically established with known SSID and password.
This mean that I need to provide the password for the WiFi network from a file, and the
remaining thing is to do the scanning and connecting automatically.
I read a file from the Web which contains WiFi SSID name and password.
I need to write a script which scan and list current networds and match it to the SSID from the file and further to automatically create the connection to this known network.
RaspberryPi OS: Rasbian
wifi is a python library for scanning and connecting to wifi networks on linux. You can use it to scan and connect to wireless networks.
It doesn’t have any built-in support for connecting automatically to a network, but you could easily write a script to do that. Here’s an example of a basic idea for how to do this.
#!/usr/bin/python
from __future__ import print_function
from wifi import Cell, Scheme
# get all cells from the air
ssids = [cell.ssid for cell in Cell.all('wlan0')]
schemes = list(Scheme.all())
for scheme in schemes:
ssid = scheme.options.get('wpa-ssid', scheme.options.get('wireless-essid'))
if ssid in ssids:
print('Connecting to %s' % ssid)
scheme.activate()
break
I just wrote it and it seems to work. Just so you know, I wrote the wifi library. If you want me to add this feature to that library, I could.
This is a monkey patch of rockymeza’s answer above, so that the Scheme will use the /etc/wpa_supplicant/wpa_supplicant.conf file instead of the /etc/network/interfaces file. I couldn’t get his Scheme class to work on my pi3s as it seems like the Schemes just adds iface wlan0-SSIDname for each network to the /etc/network/interfaces file, and there is no mapping or anything to tell it that ifup wlan0-SSIDname is associated with ‘wlan0’.
import re
from wifi import Cell, Scheme
import wifi.subprocess_compat as subprocess
from wifi.utils import ensure_file_exists
class SchemeWPA(Scheme):
interfaces = "/etc/wpa_supplicant/wpa_supplicant.conf"
def __init__(self, interface, name, options=None):
self.interface = interface
self.name = name
self.options = options or {}
def __str__(self):
"""
Returns the representation of a scheme that you would need
in the /etc/wpa_supplicant/wpa_supplicant.conf file.
"""
options = ''.join("n {k}="{v}"".format(k=k, v=v) for k, v in self.options.items())
return "network={" + options + 'n}n'
def __repr__(self):
return 'Scheme(interface={interface!r}, name={name!r}, options={options!r}'.format(**vars(self))
def save(self):
"""
Writes the configuration to the :attr:`interfaces` file.
"""
if not self.find(self.interface, self.name):
with open(self.interfaces, 'a') as f:
f.write('n')
f.write(str(self))
@classmethod
def all(cls):
"""
Returns an generator of saved schemes.
"""
ensure_file_exists(cls.interfaces)
with open(cls.interfaces, 'r') as f:
return extract_schemes(f.read(), scheme_class=cls)
def activate(self):
"""
Connects to the network as configured in this scheme.
"""
subprocess.check_output(['/sbin/ifdown', self.interface], stderr=subprocess.STDOUT)
ifup_output = subprocess.check_output(['/sbin/ifup', self.interface] , stderr=subprocess.STDOUT)
ifup_output = ifup_output.decode('utf-8')
return self.parse_ifup_output(ifup_output)
def delete(self):
"""
Deletes the configuration from the /etc/wpa_supplicant/wpa_supplicant.conf file.
"""
content = ''
with open(self.interfaces, 'r') as f:
lines=f.read().splitlines()
while lines:
line=lines.pop(0)
if line.startswith('#') or not line:
content+=line+"n"
continue
match = scheme_re.match(line)
if match:
options = {}
ssid=None
content2=line+"n"
while lines and lines[0].startswith(' '):
line=lines.pop(0)
content2+=line+"n"
key, value = re.sub(r's{2,}', ' ', line.strip()).split('=', 1)
#remove any surrounding quotes on value
if value.startswith('"') and value.endswith('"'):
value = value[1:-1]
#store key, value
options[key] = value
#check for ssid (scheme name)
if key=="ssid":
ssid=value
#get closing brace
line=lines.pop(0)
content2+=line+"n"
#exit if the ssid was not found so just add to content
if not ssid:
content+=content2
continue
#if this isn't the ssid then just add to content
if ssid!=self.name:
content+=content2
else:
#no match so add content
content+=line+"n"
continue
#Write the new content
with open(self.interfaces, 'w') as f:
f.write(content)
scheme_re = re.compile(r'network={s?')
#override extract schemes
def extract_schemes(interfaces, scheme_class=SchemeWPA):
lines = interfaces.splitlines()
while lines:
line = lines.pop(0)
if line.startswith('#') or not line:
continue
match = scheme_re.match(line)
if match:
options = {}
interface="wlan0"
ssid=None
while lines and lines[0].startswith(' '):
key, value = re.sub(r's{2,}', ' ', lines.pop(0).strip()).split('=', 1)
#remove any surrounding quotes on value
if value.startswith('"') and value.endswith('"'):
value = value[1:-1]
#store key, value
options[key] = value
#check for ssid (scheme name)
if key=="ssid":
ssid=value
#exit if the ssid was not found
if ssid is None:
continue
#create a new class with this info
scheme = scheme_class(interface, ssid, options)
yield scheme
To create the scheme, just do this:
scheme=SchemeWPA('wlan0',cell.ssid,{"ssid":cell.ssid,"psk":"yourpassword"})
Your /etc/network/interfaces file should look like this, or similar:
# interfaces(5) file used by ifup(8) and ifdown(8)
# Please note that this file is written to be used with dhcpcd
# For static IP, consult /etc/dhcpcd.conf and 'man dhcpcd.conf'
# Include files from /etc/network/interfaces.d:
source-directory /etc/network/interfaces.d
auto lo
iface lo inet loopback
iface eth0 inet manual
allow-hotplug wlan0
iface wlan0 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
iface default inet dhcp
allow-hotplug wlan1
iface wlan1 inet manual
wpa-conf /etc/wpa_supplicant/wpa_supplicant.conf
Thank you all for your answers i made simple solution like below
def wifiscan():
allSSID = Cell.all('wlan0')
print allSSID # prints all available WIFI SSIDs
myssid= 'Cell(ssid=vivekHome)' # vivekHome is my wifi name
for i in range(len(allSSID )):
if str(allSSID [i]) == myssid:
a = i
myssidA = allSSID [a]
print b
break
else:
print "getout"
# Creating Scheme with my SSID.
myssid= Scheme.for_cell('wlan0', 'home', myssidA, 'vivek1234') # vive1234 is the password to my wifi myssidA is the wifi name
print myssid
myssid.save()
myssid.activate()
wifiscan()
You can use the natively available network manager cli package (nmcli):
import subprocess
def what_wifi():
process = subprocess.run(['nmcli', '-t', '-f', 'ACTIVE,SSID', 'dev', 'wifi'], stdout=subprocess.PIPE)
if process.returncode == 0:
return process.stdout.decode('utf-8').strip().split(':')[1]
else:
return ''
def is_connected_to(ssid: str):
return what_wifi() == ssid
def scan_wifi():
process = subprocess.run(['nmcli', '-t', '-f', 'SSID,SECURITY,SIGNAL', 'dev', 'wifi'], stdout=subprocess.PIPE)
if process.returncode == 0:
return process.stdout.decode('utf-8').strip().split('n')
else:
return []
def is_wifi_available(ssid: str):
return ssid in [x.split(':')[0] for x in scan_wifi()]
def connect_to(ssid: str, password: str):
if not is_wifi_available(ssid):
return False
subprocess.call(['nmcli', 'd', 'wifi', 'connect', ssid, 'password', password])
return is_connected_to(ssid)
def connect_to_saved(ssid: str):
if not is_wifi_available(ssid):
return False
subprocess.call(['nmcli', 'c', 'up', ssid])
return is_connected_to(ssid)
Connect to a saved network:
connect_to_saved('my_wifi')
Otherwise, connect to a network with ssid and password:
connect_to('my_wifi', 'my_password')