Rsync, sshpass and QProcess

TomNow99

Hi,

I would like to use Rsync in QT. When I run this line in command line, it works:

rsync -vr --rsh="/usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user" 192.168.10.10:/abc/ /def/

So in Qt I do the same:

process->start("rsync -vr --rsh=\"/usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user\" 192.168.10.10:/abc/ /def/", args);
// args is empty QStringList()

And this doesn't work.

I find simillar topic:
https://forum.qt.io/topic/127028/unable-to-run-qprocess-with-sshpass-in-windows

So I try:

process->start("rsync", QStringList()<<"-vr"<<"--rsh=\"/usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user\""<<"192.168.10.10:/abc/"<<"/def/");

( I get output: Rsync: Failed to exec /usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user No such file or directory

And I try something like:

process->start("rsync", QStringList()<<"-vr"<<"--rsh=\"/usr/bin/sshpass"<<"-p"<<"'password'"<<"ssh"<<"-o"<<"StrictHostKeyChecking=no"<<"-p"<<"22"<<"-l"<<"user\""<<"192.168.10.10:/abc/"<<"/def/");

( I get output: unexpected remote args: 192.168.10.10:/abc/ )

JonB

@TomNow99 said in Rsync, sshpass and QProcess:

process->start("rsync -vr --rsh=\"/usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user\" 192.168.10.10:/abc/ /def/", args);

This won't work: nowadays QProcess::start() does not accept a single, command-line string to execute, you must pass just the executable as the first parameter and a QStringList of the arguments as the second parameter.

Your second two attempts are along the right lines, but doubtless you have something wrong with the separation/quoting of your arguments.

The whole of your --rsh="/usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user" looks like a single command-line argument to me. But I don't think you want the "s around it, which your command shell was dealing with. I think you want:

process->start("rsync",  QStringList()
    << "-vr"
    << "--rsh=/usr/bin/sshpass -p 'password' ssh -o StrictHostKeyChecking=no -p 22 -l user"
    << "192.168.10.10:/abc/"
    << "/def/");

?

TomNow99

@JonB It works! Thank you :)

Could you tell me, when QProcess::start() was changed to not accept a single command-line string?

JonB

@TomNow99
At 5.6-ish I think. See the current QT_NO_PROCESS_COMBINED_ARGUMENT_START. There is an obsolete void QProcess::start(const QString &command, QIODevice::OpenMode mode = ReadWrite).

However, they factored out the internal code which must have been used to split the single-string parameter, so you can now call QStringList QProcess::splitCommand(QStringView command); requires Qt 5.15.

Note that under Linux you can still run a "string" via:

process.start("/bin/sh" /*or /bin/bash*/,  QStringList() << "-c" << "echo 'hello' | wc && echo \" This is a long line with \\$PATH=$PATH\" ");

or similar. You are going via /bin/sh -c "...", which has its own quoting rules you must abide by.... We could have done your command that way, but between the sh -c quoting, the various quotings in your command, and doing it from C++ literals with \s & "s it might have been a worse brain-ache than my suggestion you took, which actually hopefully is quite "clean" :)