I wanted to do something similar.
I tried the freeware Caffeine but it was blocked by our IT policies. I ended up writing a Python script that does a similar thing (sending the keystroke F15 every xx seconds).
(It can definitely be trimmed to a minimum of lines but just got 15 minutes to spare on it so the first part is a big copy-paste of other code).
Here it is:
#!/python
import ctypes
import random
import re
import time
from argparse import ArgumentParser, HelpFormatter
LONG = ctypes.c_long
DWORD = ctypes.c_ulong
ULONG_PTR = ctypes.POINTER(DWORD)
WORD = ctypes.c_ushort
class MOUSEINPUT(ctypes.Structure):
_fields_ = (
('dx', LONG), ('dy', LONG), ('mouseData', DWORD),
('dwFlags', DWORD), ('time', DWORD),
('dwExtraInfo', ULONG_PTR)
)
class KEYBDINPUT(ctypes.Structure):
_fields_ = (
('wVk', WORD), ('wScan', WORD),
('dwFlags', DWORD), ('time', DWORD),
('dwExtraInfo', ULONG_PTR)
)
class _INPUTunion(ctypes.Union):
_fields_ = (
('mi', MOUSEINPUT),
('ki', KEYBDINPUT)
)
class INPUT(ctypes.Structure):
_fields_ = (('type', DWORD), ('union', _INPUTunion))
def SendInput(*inputs):
nInputs = len(inputs)
LPINPUT = INPUT * nInputs
pInputs = LPINPUT(*inputs)
cbSize = ctypes.c_int(ctypes.sizeof(INPUT))
return ctypes.windll.user32.SendInput(nInputs, pInputs, cbSize)
INPUT_MOUSE = 0
INPUT_KEYBOARD = 1
def Input(structure):
if isinstance(structure, MOUSEINPUT):
return INPUT(INPUT_MOUSE, _INPUTunion(mi=structure))
elif isinstance(structure, KEYBDINPUT):
return INPUT(INPUT_KEYBOARD, _INPUTunion(ki=structure))
else:
raise TypeError('Cannot create INPUT structure (keyboard)!')
keys = {
'DEFAULT': 0x7E, # F15 key
'SNAPSHOT': 0x2C, # PRINT SCREEN key
'F1': 0x70, # F1 key
'F2': 0x71, # F2 key
'F3': 0x72, # F3 key
'F4': 0x73, # F4 key
'F5': 0x74, # F5 key
'F6': 0x75, # F6 key
'F7': 0x76, # F7 key
'F8': 0x77, # F8 key
'F9': 0x78, # F9 key
'F10': 0x79, # F10 key
'F11': 0x7A, # F11 key
'F12': 0x7B, # F12 key
'F13': 0x7C, # F13 key
'F14': 0x7D, # F14 key
'F15': 0x7E, # F15 key
'F16': 0x7F, # F16 key
'F17': 0x80, # F17 key
'F18': 0x81, # F18 key
'F19': 0x82, # F19 key
'F20': 0x83, # F20 key
'F21': 0x84, # F21 key
'F22': 0x85, # F22 key
'F23': 0x86, # F23 key
'F24': 0x87, # F24 key
}
def Keyboard(code, flags=0):
# Code for key 0..9 or A..Z: it corresponds to the the ASCII code
if len(code) == 1 and re.match(r'[0-9A-Za-z]', code):
key = ord(code.upper())
# Keys 'F...': we use code in the dictionary
else:
key = keys.get(code.upper(), keys['DEFAULT'])
return Input(KEYBDINPUT(key, key, flags, 0, None))
############################################################################
sentences = [
"Don't sleep!",
"Stay awake!",
"Are you still here?",
"Hello...",
"Want some coffee?",
"What are you doing?"
]
def keep_alive(delay, nb_cycles=-1, key='F15'):
"""
Send keystroke F15 at a given delay for a given nb of cycles
Args:
delay(int): delay in seconds
nb_cycles(int): number of cycles (set to -1 for unlimited)
key(str): Key to send (default: 'F15')
"""
print("Trust me, I will keep you alive!\n")
while nb_cycles != 0:
time.sleep(delay)
SendInput(Keyboard(key))
print(random.choice(sentences))
nb_cycles -= 1
if __name__ == '__main__':
# Information on the Program
copyright_year = 2018
prog = "stay_awake"
version_str = "%s v1.0" % prog
help_string = """\
Purpose: Send a keystroke (F15) to simulate user activity
"""
# Options
parser = ArgumentParser(
description=help_string, prog=prog,
formatter_class=lambda prog:
HelpFormatter(prog, max_help_position=60)
)
parser.add_argument(
"-k", "--key",
type=str, default='F15',
help="Key to send [Dflt: F15]"
)
parser.add_argument(
"-d", "--delay",
type=int, default=234,
help="Delay (in s) between keystrokes [Dflt: 234]"
)
parser.add_argument(
"-r", "--duration",
type=int, default=-1,
help="Duration (in s) or negative value for infinite"
)
options = parser.parse_args()
# Run
nb_cycles = options.duration if options.duration < 0 \
else int(options.duration/options.delay)
keep_alive(options.delay, nb_cycles, key=options.key)
