[Solved] Reboot on Linux embedded

[Asperamanca]

I am trying to reboot a linux embedded device using QProcess.

I have tried various ways, and none of them seem to work:

a)
@
QProcess shellCommand;
shellCommand.startDetached("reboot");
@

b)
@
QProcess shellCommand;
shellCommand.start("reboot");
shellCommand.waitForFinished();
@

c)

@
QProcess shellCommand;
shellCommand.start("shutdown -r");
shellCommand.waitForFinished();
@

d)

@
QProcess shellCommand;
shellCommand.start("sh -c reboot");
shellCommand.waitForFinished();
@

I have tested all the command using telnet. Every one of them reboots the system.
I have also ensured that my application runs as root.
The QProcess in attempts b) to d) always exits with "NormalExit", and an exit code of zero.

Ideas?

[Asperamanca]

Note: My application uses about 80 % of the available system memory, which is all right because it's the only application running.

Does QProcess consume a lot of memory?

[blaroche]

can you try using the full path to reboot or shutdown?

[Asperamanca]

I think I know what's the problem:
The fork that must be somewhere inside QProcess can't work, because there isn't enough memory left to fork the current application. Why I wouldn't get an error state I don't know.

I have solved this by having a worker script run in an endless loop that will execute any shell script following a specific naming convention. I create a script containing the reboot command, and let it execute.

[thehilmisu]

have you tried to add "0" to your shell command ? "shutdown -r 0".
@QProcess shellCommand;
shellCommand.start("shutdown -r 0");
shellCommand.waitForFinished();@

if it does not work, may be the problem cause that you are not the root.

[Asperamanca]

I am root. And it used to work, before I expanded the buffers to use most of the available memory for archiving.

[luca]

Suppose your command is in /usr/sbin/reboot you can try with:
@
QProcess::startDetached("/usr/sbin/reboot");
@

[Asperamanca]

My first try was based on startDetached. It seems to do a fork internally, too.

[luca]

Have you tried with the full path of reboot command?

[Asperamanca]

No. Plain Reboot used to work just fine. Colleagues with 20+ years of Unix experience assured me this is an underlying OS limitation.