Simple Python script for automating the installation of signal-cli, the DBus service, and registering a new user. Fork of https://gist.github.com/Vic3198/f0c9e17ef3d70e7b8c066bfd8cf4db2d

InstallSignalEN.py

# Run this Python 3 script with superuser rights ('sudo') to install the Signal client

input("Welcome to the signal-cli install wizard.\nPress ENTER when you are ready.")

import os

yes = ['Oui', 'Yes', 'O', 'Y', 'oui', 'yes', 'o', 'y']


javaInstalled = input(
    "\n\nSignal requires Java and the Java Cryptography extension.\n"
    "For Java, just do 'sudo apt install openjdk-17-jdk'.\n"
    "For the JCE, download it at http://www.oracle.com/technetwork/java/javase/downloads/jce8-download-2133166.html\n"
    "and copy the files in /usr/lib/jvm/<the Java folder>/lib/security/"
    "\nReplace the existing files if needed.\n"
    "Are Java and the JCE extension correctly installed? (Yes/No): "
)

if javaInstalled in yes:
    # Ask for Signal number and check if input is matching the required format
    numberOK = False
    while not numberOK:
        number = input(
            "\nType in the phone number that will be associated to your Signal account.\n"
            "This number must be formatted as follows: +CCXXXXXXXXX (CC : Country Code).\n"
            "e.g. for France: +33601020304.\n"
            "Number: "
        )
        numberOK = number[0] == "+" and number[1:].isdecimal()
        if not numberOK:
            print("\nThis is not a valid number. Please retry.")

    captchaToken = None
    captchaNeeded = input(
        "\nIf you are running this script again,\n"
        "did your previous registration fail with captcha required error? (Yes/No): "
    )
    if captchaNeeded in yes:
        captchaToken = input(
            "\nObtain a captcha token by following the instructions "
            "at https://github.com/AsamK/signal-cli/wiki/Registration-with-captcha.\n"
            "Paste the token here: "
        )
        # Omit "signalcaptcha://"
        if captchaToken.startswith("signalcaptcha://"):
            captchaToken = captchaToken[len("signalcaptcha://"):]

    # Ask for Signal version and check if input is matching the required format
    versionOK = False
    while not versionOK:
        version = input(
            "\nPlease check the latest signal-cli version\n"
            "on https://github.com/AsamK/signal-cli/releases and write it below.\n"
            "The format must be x.y.z. e.g. : 0.8.1\n"
            "Version: "
        )
        # Original author didn't know numbers could be larger than 9
        versionOK = version.count(".") == 2 and all(s.isdecimal() for s in version.split("."))
        if not versionOK:
            print("\nThis is not a valid number. Please retry.")

    # Filename now includes OS
    new_filename = "signal-cli-" + version + "-Linux.tar.gz"
    os.system("cd /tmp ; wget https://github.com/AsamK/signal-cli/releases/download/v" + version + "/" + new_filename)
    # Revert filename format because I'm scared of breaking things
    os.system("mv /tmp/{} /tmp/{}".format(new_filename, "signal-cli-" + version + ".tar.gz"))
    os.system("tar xf /tmp/signal-cli-" + version + ".tar.gz -C /opt ; ln -sf /opt/signal-cli-" + version + "/bin/signal-cli /usr/local/bin/")
    os.system("apt install -y git")
    os.system("cd /tmp ; git clone https://github.com/AsamK/signal-cli.git")
    os.system("cd /tmp/signal-cli/data ; cp org.asamk.Signal.conf /etc/dbus-1/system.d/ ; cp org.asamk.Signal.service /usr/share/dbus-1/system-services/ ; cp signal-cli.service /etc/systemd/system/")
    os.system("""sed -i -e "s|%dir%|/opt/signal-cli-""" + version + """/|" -e "s|%number%|""" + number + """|" /etc/systemd/system/signal-cli.service""")

    os.system("""sed -i -e 's|policy user="signal-cli"|policy user="root"|' /etc/dbus-1/system.d/org.asamk.Signal.conf""")
    os.system("""sed -i -e 's|User=signal-cli|User=root|' /etc/systemd/system/signal-cli.service""")

    installMode = input(
        "\nA Signal account might be installed on several devices.\n"
        "In this case, one of them is the master device,\nand the others must be linked via a QR Code before use.\n"
        "Will this computer be used as the master device for your Signal account? (Yes/No): "
    )

    if installMode in yes:
        sms = input(
            "\nA validation PIN will be sent to the provided phone number.\n"
            "If this phone cannot receive SMS (landline), the PIN will be given by a call.\n"
            "Can this phone number receive SMS? (Yes/No): "
        )

        command = "signal-cli --config /var/lib/signal-cli -u " + number + " register"
        if sms not in yes:
            command += " --voice"
        if captchaToken:
            command += " --captcha " + captchaToken
        os.system(command)

        # Ask for verfication code and check if input is matching the required format
        verifOK = False
        while not verifOK:
            verifCode = input("Enter the 6-digit validation PIN you just received: ")
            verifOK = len(verifCode) == 6 and verifCode.isdecimal()
            if not verifOK:
                print("\nThis is not a valid number. Please retry.")

        os.system('signal-cli --config /var/lib/signal-cli -u ' + number + ' verify ' + verifCode)

    else:
        deviceName = input(
            '\nYou are about to generate a link beginning by sgnl://...\n'
            'Copy it and paste it in a QR Code generator, like https://www.the-qrcode-generator.com/.\n'
            'Be careful to choose "Text", not "Link" in the generator.\n'
            'Use the Signal app on your phone to flash the generated QR code.\n'
            'How do you want to name your device?: '
        )
        os.system('''signal-cli --config /var/lib/signal-cli link -n "''' + deviceName + '''"''')

    os.system("apt install libunixsocket-java")
    os.system("cp /usr/lib/jni/libunix-java.so /lib") # Because sometimes it says that libunix-java is not in java.library.path
    os.system("systemctl daemon-reload && systemctl enable signal-cli.service && systemctl reload dbus.service && systemctl start signal-cli.service")

    print("\nInstallation finished.")

    numberOK = False
    while not numberOK:
        number = input(
            "\nIn order to check if the installation completed correctly,\n"
            "please provide a phone number linked to a Signal account (not this one).\n"
            "This number must be formatted as follows: +CCXXXXXXXXX (CC : Country Code).\n"
            "e.g. for France: +33601020304.\n"
            "Number: "
        )
        numberOK = number[0] == "+" and number[1:].isdecimal()
        if not numberOK:
            print("\nThis is not a valid number. Please retry.")
        else:
            os.system('''signal-cli --dbus-system send -m "Everything works as expected. The signal-cli client installation is finished.\nWell done!" ''' + number)
            received = input("\nA message has just been sent to this number.\nHave you received it? (Yes/No): ")
            if received not in yes:
                numberOK = False

Thanks..
This script working fine.
could you tell me that how can I see incoming message?