linux ec20 使用哪个/dev/ttyUSBx进行pppd连接

在Linux中，EC20连接到电脑后会被识别为一个USB串口设备。可以通过以下步骤来确定使用哪个`/dev/ttyUSBx`进行pppd连接：

1. 插入EC20模块并确认已正确安装驱动程序。
2. 打开终端并输入以下命令：`dmesg | grep ttyUSB`，会显示EC20模块的USB串口设备信息，其中会包含`/dev/ttyUSBx`的信息，x是一个数字。
3. 执行`ls -l /dev/ttyUSB*`命令，可以查看所有USB串口设备的权限和所有者信息，可以根据需要选择一个可用的设备进行pppd连接。

请注意，`/dev/ttyUSBx`的编号可能会随着电脑上其他USB设备的插拔而改变，因此建议在使用pppd之前先确认一下该设备是否可用。

相关问题

我有一个安卓ppp脚本，如何让它在开机时自动调用：# /etc/ppp/peers/quectel-pppd # Usage:root>pppd call quectel-pppd #Modem path, like /dev/ttyUSB3,/dev/ttyACM0, depend on your module, default path is /dev/ttyUSB3 /dev/ttyUSB3 115200 #Insert the username and password for authentication, default user and password are test user "test" password "test" # The chat script, customize your APN in this file connect 'chat -s -v -f /etc/ppp/peers/quectel-chat-connect' # The close script disconnect 'chat -s -v -f /etc/ppp/peers/quectel-chat-disconnect' # Hide password in debug messages hide-password # The phone is not required to authenticate noauth # Debug info from pppd debug # If you want to use the HSDPA link as your gateway defaultroute # pppd must not propose any IP address to the peer noipdefault # No ppp compression novj novjccomp noccp ipcp-accept-local ipcp-accept-remote local # For sanity, keep a lock on the serial line modem dump nodetach # Hardware flow control nocrtscts remotename 3gppp ipparam 3gppp ipcp-max-failure 30 # Ask the peer for up to 2 DNS server addresses usepeerdns并且在脚本中添加下面这一操作：

你可以将这个脚本放在 /etc/init.d/ 目录下，并添加启动脚本来确保它在开机时被调用。具体步骤如下：

1. 将脚本复制到 /etc/ppp/peers/quectel-pppd 中。

2. 创建一个启动脚本 /etc/init.d/quectel-pppd，内容如下：

#!/bin/sh
# chkconfig: 2345 99 01
# description: auto start quectel-pppd

case "$1" in
start)
    echo "Starting quectel-pppd..."
    /usr/sbin/pppd call quectel-pppd
    ;;
stop)
    echo "Stopping quectel-pppd..."
    killall pppd
    ;;
restart)
    $0 stop
    sleep 1
    $0 start
    ;;
*)
    echo "Usage: $0 {start|stop|restart}"
    ;;
esac
exit 0

3. 添加执行权限：

chmod +x /etc/init.d/quectel-pppd

4. 将脚本添加到启动项中：

update-rc.d quectel-pppd defaults

这样，在下一次重启后，quectel-pppd 脚本将会自动被调用。

cannot access '/dev/ppp0': No such file or directory

As an AI language model, I do not have access to your system resources, but I can provide you with some general information.

The error message "cannot access '/dev/ppp0': No such file or directory" indicates that the device file for the Point-to-Point Protocol (PPP) interface is not present in the /dev directory. This could be due to several reasons, such as:

1. The PPP module is not loaded: Check if the PPP module is loaded in the kernel. You can do this by running the command "lsmod | grep ppp". If it is not loaded, load it using the command "modprobe ppp".

2. The pppd daemon is not running: Check if the pppd daemon is running using the command "ps -ef | grep pppd". If it is not running, start it using the command "sudo pppd call <connection_name>".

3. The PPP interface is not created: Check if the PPP interface is created using the command "ifconfig -a". If it is not created, create it using the command "sudo pppd call <connection_name>".

If none of the above solutions work, it is possible that the PPP driver is not installed or is corrupted. Try reinstalling the PPP driver or updating your system.