Re^2: Win32 limit to number of calls to system()?

BrowserUk,
The code looks something like this:

for my $pdf (glob('*.pdf')) {
    my $txt = convert_pdf_to_text($pdf);
    next if ! interesting($txt);
    # ...
}

sub convert_pdf_to_text {
    my ($file) = @_;
    my $abs_file = rel2abs(catfile(curdir(), $file));

    ## Start Simpo PDF To Text 
    system(1, 'C:\Program Files\Simpo PDF to Text\PDF2Text.exe');

    # Locate the window
    my $wid = WaitWindow('Simpo PDF to Text', 5);
    die "Couldn't find 'Simpo PDF to Text' window" if ! defined $wid;

    ## Make sure it is on top
    SetForegroundWindow($wid);

    # Convert PDFs
    add_pdf($abs_file);
    convert();

    # Close the application
    SendKeys('%{F4}');

    my $txt_file = construct_txt_file($file);
    return '' if ! -r $txt_file;
    my $data = read_file($txt_file);
    unlink $txt_file or die $!;
    return $data;
}
[download]

As you can see, I use system(1, $app) to start the application and alt+f4 to close the application (before starting the new one). I have already worked around the problem by leaving the app open. Just not sure why this doesn't work as I would expect.

Cheers - L~R

Comment on Re^2: Win32 limit to number of calls to system()? Download Code

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Re^3: Win32 limit to number of calls to system()? by ikegami (Patriarch) on Sep 13, 2011 at 04:09 UTC
You don't reap. Use `waitpid($pid)`, the pid being returned by `system 1`.	[reply] [d/l] [select]
Re^3: Win32 limit to number of calls to system()? by BrowserUk (Patriarch) on Sep 13, 2011 at 08:19 UTC
Either of these will work: Use a synchronous system and the `start` command. This will synchronously run a copy of `cmd.exe` to run the start command, and it starts the program asynchronously. As `cmd.exe` returns immediately and the synchronous system gathers its exit code, it avoids the accumulation of zombies and the `WaitForMultipleObjects()` problem: `for ( 1 .. 100 ) { print "spawning job $_"; system 'start \\Windows\\system32\\notepad.exe'; my $wid = WaitWindow( 'Notepad', 1 ); SetForegroundWindow( $wid ); SendKeys( '%{F4}' ); }` [download] Use the asynchronous system and obtain the pid of the started instance from the returned value. Use waitpid to gather the exit code thus avoiding the accumulation of the zombies: `for ( 1 .. 100 ) { print "spawning job $_"; my $pid = system 1, '/Windows/system32/notepad.exe'; my $wid = WaitWindow( 'Notepad', 1 ); SetForegroundWindow( $wid ); SendKeys( '%{F4}' ); waitpid $pid, 1; }` [download] Finally, `'Simpo PDF to Text'` has a 'batch mode' which would be possible -- if awkward -- to drive programmically, but it might be substantially more efficient. I guess you've already looked at command line driven alternatives? Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l] [select]
Re^4: Win32 limit to number of calls to system()? by Limbic~Region (Chancellor) on Sep 13, 2011 at 17:10 UTC
BrowserUk, Finally, 'Simpo PDF to Text' has a 'batch mode' which would be possible That is one of the reasons I purchased it. Unfortunately, it is 'batch mode' through the UI and not command line. For my purposes, I need to make a decision after conversion before the next file that does not easily allow me to use the batch mode. I guess you've already looked at command line driven alternatives? Nothing I looked at did as good a job as Simpo's tool on the particular PDFs I was using. I have used a multitude of OCR tools in the past but I need to keep structure as well as text and it was the best I found for this particular data set. Cheers - L~R	[reply]