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Nigel W Johnson's questions

Martin Hope
Nigel W Johnson
Asked: 2023-05-07 09:11:53 +0800 CST
  • 5

我有一个使用 msqllib 的程序。它扫描我构建的一些硬件，然后更新 mysql 数据库。这个程序已经运行了很多年，但我从来没有能够在系统重新启动时自动启动它。现在我遇到了一个我无法控制的电源循环问题，所以想让它自动运行。

在 rc.local 中：我有：

#!/bin/sh -e
#
# rc.local
#
# This script is executed at the end of each multiuser runlevel.
# Make sure that the script will "exit 0" on success or any other
# value on error.
#
# In order to enable or disable this script just change the execution
# bits.
#
# By default this script does nothing.

# Print the IP address
_IP=$(hostname -I) || true
if [ "$_IP" ]; then
  printf "My IP address is %s\n" "$_IP"
fi
/home/nigel/scan
exit 0

现在，当我在命令提示符下输入代码并更新我的数据库时，代码运行良好。但是，当我把它放在 rc.local 中时， ps -ef 显示：

root       356   350  0 20:54 ?        00:00:03 /home/nigel/scan

但是程序没有执行更新数据库的 SQL 调用。

如果我询问 rc.local 的状态：

root@Pi-Scan:~# systemctl status rc-local.service
● rc-local.service - /etc/rc.local Compatibility
   Loaded: loaded (/lib/systemd/system/rc-local.service; enabled-runtime; vendor preset: enabled)
  Drop-In: /usr/lib/systemd/system/rc-local.service.d
           └─debian.conf
           /etc/systemd/system/rc-local.service.d
           └─ttyoutput.conf
   Active: activating (start) since Sat 2023-05-06 20:54:19 EDT; 12min ago
     Docs: man:systemd-rc-local-generator(8)
Cntrl PID: 350 (rc.local)
    Tasks: 2 (limit: 414)
      CPU: 3.903s
   CGroup: /system.slice/rc-local.service
           ├─350 /bin/sh -e /etc/rc.local start
           └─356 /home/nigel/scan

May 06 20:54:21 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:22 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:23 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:24 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:25 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:26 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:27 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected
May 06 20:54:28 Pi-Scan rc.local[356]: error: first parameter is not a valid address family: Transport endpoint is not connected

但是，如果我发出systemctl restart rc-local.service 该程序执行第二个实例并且工作正常！

考虑到这可能是赛车条件，我尝试在命令前添加一个 sleep 5，但仍然遇到同样的问题。

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