[Spice-devel] [PATCH] Add utility to help redirecting output from remote-viewer/virt-viewer

[Frediano Ziglio]

> 
> Hi
> 
> ----- Original Message -----
> > These utility use some trick to use console even if they are GUI
> > application (not supposed to have a console by default).
> > This make output redirection harder as output by default will tend
> > to go to console of parent process instead of using redirected output.
> > This utility avoid remote-viewer/virt-viewer to see the calling process
> > console keeping the wanted redirection.
> 
> This looks like it should replace windows-cmdline-wrapper altogether.
> 

Really? I though the two utility were written for different purposes.
I though your utility was a complement of the AttachConsole in the executable
so the executable detect them and can provide some control/feedback using
the console.

If it's just redirect to console if parent has a console or to file if we
want to redirect to file probably we can find a solution in
virt-viewer/remote-viewer that satisfy both requirements.

Frediano

> > 
> > Signed-off-by: Frediano Ziglio <fziglio at redhat.com>
> > ---
> >  src/Makefile.am               |  4 ++
> >  src/output-redirect-wrapper.c | 92
> >  +++++++++++++++++++++++++++++++++++++++++++
> >  2 files changed, 96 insertions(+)
> >  create mode 100644 src/output-redirect-wrapper.c
> > 
> > diff --git a/src/Makefile.am b/src/Makefile.am
> > index e76f5bc..01b9bc8 100644
> > --- a/src/Makefile.am
> > +++ b/src/Makefile.am
> > @@ -155,6 +155,10 @@ bin_PROGRAMS += windows-cmdline-wrapper
> >  windows_cmdline_wrapper_SOURCES = windows-cmdline-wrapper.c
> >  windows_cmdline_wrapper_LDFLAGS = -lpsapi
> >  
> > +bin_PROGRAMS += output-redirect-wrapper
> > +output_redirect_wrapper_SOURCES  = output-redirect-wrapper.c
> > +output_redirect_wrapper_CPPFLAGS = -DUNICODE -D_UNICODE
> > +
> >  virt-viewer_rc.$(OBJEXT): $(VIRT_VIEWER_RES) $(ICONDIR)/virt-viewer.ico
> >  	$(AM_V_GEN)$(WINDRES)				\
> >  		-DICONDIR='\"$(ICONDIR)\"'		\
> > diff --git a/src/output-redirect-wrapper.c b/src/output-redirect-wrapper.c
> > new file mode 100644
> > index 0000000..ed807bb
> > --- /dev/null
> > +++ b/src/output-redirect-wrapper.c
> > @@ -0,0 +1,92 @@
> > +/*
> > + * Windows cmd: a command line wrapper for GUI applications
> > + *
> > + * Copyright (C) 2012-2016 Red Hat, Inc.
> > + *
> > + * This program is free software; you can redistribute it and/or modify
> > + * it under the terms of the GNU General Public License as published by
> > + * the Free Software Foundation; either version 2 of the License, or
> > + * (at your option) any later version.
> > + *
> > + * This program is distributed in the hope that it will be useful,
> > + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
> > + * GNU General Public License for more details.
> > + *
> > + * You should have received a copy of the GNU General Public License
> > + * along with this program; if not, write to the Free Software
> > + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307
> > USA
> > + *
> > + * Usage:
> > + * This wrapper allows to redirect output even if your application
> > + * tries to redirect its output to console.
> > + *
> > + * For instance you can use from console with a syntax like
> > + *
> > + *   output-redirect-wrapper remote-viewer.exe --debug > log.txt
> > + *
> > + * Based on Marc-André Lureau wrappers
> > + */
> > +
> > +#include <windows.h>
> > +#include <stdio.h>
> > +#include <string.h>
> > +#include <tchar.h>
> > +
> > +int main(void)
> > +{
> > +    STARTUPINFO si = { 0, };
> > +    PROCESS_INFORMATION pi = { 0, };
> > +
> > +    // pass same input/output handles
> > +    si.cb = sizeof(si);
> > +    si.dwFlags = STARTF_USESTDHANDLES;
> > +    si.hStdInput  = GetStdHandle(STD_INPUT_HANDLE);
> > +    // redirect all to single output
> > +    si.hStdError = si.hStdOutput = GetStdHandle(STD_OUTPUT_HANDLE);
> > +    SetHandleInformation(si.hStdInput,  HANDLE_FLAG_INHERIT,
> > HANDLE_FLAG_INHERIT);
> > +    SetHandleInformation(si.hStdOutput, HANDLE_FLAG_INHERIT,
> > HANDLE_FLAG_INHERIT);
> > +
> > +    // parse command line, strip executable
> > +    TCHAR *cmdline = GetCommandLine();
> > +    cmdline += _tcsspn(cmdline, _T(" \t\v"));
> > +    TCHAR *end = _tcsstr(cmdline, cmdline[0] == _T('\"') ? _T("\" ") :
> > _T("
> > "));
> > +    if (!end) {
> > +        fprintf(stderr, "Please pass executable to call\n");
> > +        return 1;
> > +    }
> > +    cmdline = end + 1;
> > +    cmdline += _tcsspn(cmdline, _T(" \t\v"));
> > +
> > +    // release console so program launched do not redirect to it
> > +    FreeConsole();
> > +
> > +    if (!CreateProcess(NULL,
> > +                       cmdline,
> > +                       NULL,           // Process handle not inheritable
> > +                       NULL,           // Thread handle not inheritable
> > +                       TRUE,           // Handle inheritance
> > +                       0,              // No creation flags
> > +                       NULL,           // Use parent's environment block
> > +                       NULL,           // Use parent's starting directory
> > +                       &si,
> > +                       &pi)) {
> > +        fprintf(stderr, "CreateProcess failed (%ld).\n", (long)
> > GetLastError());
> > +        return 1;
> > +    }
> > +    // Close unneeded handle
> > +    CloseHandle(pi.hThread);
> > +
> > +    // Wait until child process exits.
> > +    WaitForSingleObject(pi.hProcess, INFINITE);
> > +
> > +    DWORD exit_code;
> > +    GetExitCodeProcess(pi.hProcess, &exit_code);
> > +
> > +    // Close process handle
> > +    CloseHandle(pi.hProcess);
> > +
> > +    // return same output of application
> > +    ExitProcess(exit_code);
> > +    return 0;
> > +}
> > --
> > 2.5.0
> > 
> > _______________________________________________
> > Spice-devel mailing list
> > Spice-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/spice-devel
> > 
>