Thanks to both of you for diagnostic suggestions. The problem turned out to be so strange (to me at least) that I thought it was worth showing here.
This is a Tk app, with the Win32::Process stuff in a separate module named PPSSubs. It turns out that if the "use PPSSubs" is in one place in the main program, Process waits, but in another place, it doesn't. I'd sure like to know the reason for this!
Here's the code -- fully runnable. I'm using ActiveState Perl 5.8.8.819. First the main program:
$::winheading = $::mainwin->Label
(
-background => '#b5bfcc',
-foreground => '#0000a0',
-font => 'Verdana 14 bold',
-text => "MWeb\x{2122} Preprocessing System",
);
$::beginbutton = $::mainwin->Button
(
-text => 'Begin',
-default => 'active',
-state => 'active',
-font => '{MS Sans Serif} 10 bold',
-width => '9',
-command => \&MainSub,
);
$::settingsbutton = $::mainwin->Button
(
-text => 'Settings',
-default => 'active',
-state => 'active',
-font => '{MS Sans Serif} 10 bold',
-width => '9',
);
$::cancelbutton = $::mainwin->Button
(
-text => 'Close',
-font => '{MS Sans Serif} 10 bold',
-width => '9',
-command => sub { exit; }
);
$::helplabel = $::mainwin->Label
(
-background => '#b5bfcc',
-foreground => '#0000a0',
-font => 'Arial 9 bold',
-text => "For Help go to http://systemsplanning.com/mweb/ppsadmin.
+asp",
);
$::progresstext = $::mainwin->Scrolled
(
'ROText',
-background => '#ffffff',
-foreground => '#000000',
-font => 'Arial 10',
-height => 10,
-scrollbars => 'oe',
);
$::SPlabel = $::mainwin->Label
(
-background => '#b5bfcc',
-foreground => '#0000a0',
-font => 'Verdana 10',
-text => 'Systems Planning',
);
$::clientlabel = $::mainwin->Label
(
-text => 'Client code',
-background => '#ffffff',
-font => 'Verdana 10',
);
$::clientbox = $::mainwin->Entry
(
-background => '#ffffff',
-font => 'Verdana 10',
-takefocus => 1,
);
$::startatlabel = $::mainwin->Label
(
-text => 'Program to start at',
-background => '#ffffff',
-font => 'Verdana 10',
);
$::startatbox = $::mainwin->Entry
(
-background => '#ffffff',
-font => 'Verdana 10',
-takefocus => 1,
);
$::runonlylabel = $::mainwin->Label
(
-text => 'Run only this program',
-background => '#ffffff',
-font => 'Verdana 10',
);
$::runonlybox = $::mainwin->Entry
(
-background => '#ffffff',
-font => 'Verdana 10',
-takefocus => 1,
);
$::copylabel = $::mainwin->Label
(
-background => '#b5bfcc',
-foreground => '#0000a0',
-font => 'Verdana 10',
-text => 'Copyright © 2000-2007',
);
# GEOMETRY MANAGEMENT
$::winheading->grid
(
-in => $::mainwin,
-column => '0',
-row => '0',
-columnspan => '4',
-ipadx => '0',
-ipady => '0',
-padx => '0',
-pady => '0',
-rowspan => '1',
-sticky => ''
);
$::beginbutton->grid
(
-in => $::mainwin,
-column => '0',
-row => '1',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '0',
-pady => '0',
-rowspan => '1',
-sticky => 'e'
);
$::settingsbutton->grid
(
-in => $::mainwin,
-column => '2',
-row => '1',
-columnspan => '1',
-ipadx => '4',
-ipady => '0',
-padx => '0',
-pady => '0',
-rowspan => '1',
-sticky => ''
);
$::cancelbutton->grid
(
-in => $::mainwin,
-column => '3',
-row => '1',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '0',
-pady => '0',
-rowspan => '1',
-sticky => 'w'
);
$::helplabel->grid
(
-in => $::mainwin,
-column => '0',
-row => '2',
-columnspan => '4',
-ipadx => '0',
-ipady => '0',
-padx => '0',
-pady => '0',
-rowspan => '1',
-sticky => ''
);
$::progresstext->grid
(
-in => $::mainwin,
-column => '0',
-row => '4',
-columnspan => '4',
-ipadx => '0',
-ipady => '0',
-padx => '0',
-pady => '0',
-rowspan => '1',
-sticky => ''
);
$::SPlabel->grid
(
-in => $::mainwin,
-column => '0',
-row => '7',
-columnspan => '2',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => 'w'
);
$::clientlabel->grid
(
-in => $::mainwin,
-column => '1',
-row => '5',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => ''
);
$::clientbox->grid
(
-in => $::mainwin,
-column => '2',
-row => '5',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => ''
);
$::startatlabel->grid
(
-in => $::mainwin,
-column => '1',
-row => '6',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => ''
);
$::startatbox->grid
(
-in => $::mainwin,
-column => '2',
-row => '6',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => ''
);
$::runonlylabel->grid
(
-in => $::mainwin,
-column => '1',
-row => '7',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => ''
);
$::runonlybox->grid
(
-in => $::mainwin,
-column => '2',
-row => '7',
-columnspan => '1',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => ''
);
$::copylabel->grid
(
-in => $::mainwin,
-column => '2',
-row => '7',
-columnspan => '2',
-ipadx => '0',
-ipady => '0',
-padx => '2',
-pady => '2',
-rowspan => '1',
-sticky => 'e'
);
$::mainwin->gridRowconfigure(0, -weight => 0, -minsize => 40, -pad =>
+0);
$::mainwin->gridRowconfigure(1, -weight => 0, -minsize => 60, -pad =>
+0);
$::mainwin->gridRowconfigure(2, -weight => 0, -minsize => 20, -pad =>
+0);
$::mainwin->gridRowconfigure(3, -weight => 0, -minsize => 20, -pad =>
+0);
$::mainwin->gridRowconfigure(4, -weight => 0, -minsize => 60, -pad =>
+0);
$::mainwin->gridRowconfigure(5, -weight => 0, -minsize => 30, -pad =>
+0);
$::mainwin->gridRowconfigure(6, -weight => 0, -minsize => 30, -pad =>
+0);
$::mainwin->gridColumnconfigure(0, -weight => 0, -minsize => 170, -pad
+ => 0);
$::mainwin->gridColumnconfigure(1, -weight => 0, -minsize => 170, -pad
+ => 0);
$::mainwin->gridColumnconfigure(2, -weight => 0, -minsize => 170, -pad
+ => 0);
$::mainwin->gridColumnconfigure(3, -weight => 0, -minsize => 170, -pad
+ => 0);
$::mainwin->bind('<Return>' => [$::beginbutton => 'Invoke']);
