GNU find from QProcess - Cannot use exec parameter

Question

I'm running GNU find in a QProcess which works just fine. Nevertheless, when I try to combine it with grep, it does not execute at all.

The QProcess is started with

process->start(findpattern.replace("~",QDir::home().absolutePath()), QProcess::Unbuffered | QProcess::ReadWrite);

When findpattern is e.g.

find "~/Downloads" -name "*.cpp"

this works just fine. But for e.g. finding all cpp files that contain "else"

find "~/Downloads" -name "*.cpp" -exec grep -l "else" {} \; 

it fails

What am I doing wrong?

Answer 1

The purpose of the backslash in {} \; is that the shell doesn't interpret the semicolon as a separator to the next command. This backslash will be removed by the shell and not passed to find.

But QProcess runs find directly, not through a shell, so that backslash should not be there.

From find's manpage:

   -exec command ;
          Execute command; true if 0 status is returned.  All following arguments to
          find are taken to be arguments to the command until an argument consisting
          of `;' is encountered.  The string `{}' is replaced by  the  current  file
          name being processed everywhere it occurs in the arguments to the command,
          not just in arguments where it is alone, as  in  some  versions  of  find.
          Both  of  these  constructions  might  need  to be escaped (with a `\') or
          quoted to protect them from expansion by the shell