Re: Temporary files and cleaning up after an interruption

Says tye:

How does a child wait for a parent to exit? (use flock as an IPC mechanism)

That's nice. Thanks for the idea.

Here's an alternative mechanism. I think this might be more commonly used:

#!/usr/bin/perl

pipe R, W or die;
die unless defined my $pid = fork;
if ($pid) {
  # parent
  close R;
  print "parent: I'm going to do some work now\n";
  for (1 .. rand 12) {
    print "Parent is working...\n";
    sleep 1;
  }
  print "parent: exiting\n";
} else {  # child
  close W;
  print "child: waiting for parent to exit\n";
  <R>;
  print "child: parent exited; exiting\n";
}
[download]

I used this technique extensively in my obfuscated contest entry.

Comment on Re: Temporary files and cleaning up after an interruption Download Code

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Re: Temporary files and cleaning up after an interruption by Dominus (Parson) on Jan 05, 2001 at 08:45 UTC
Says tye: How does a child wait for a parent to exit? (use `flock` as an IPC mechanism) Another related technique: `# in the child: while (whatever...) { do_some_work(); if (getppid() == 1) { print "my parent is dead!"; clean_up(); exit; } }` [download]	[reply] [d/l]
(tye)Re2: Temporary files and cleaning up after an interruption by tye (Sage) on Jan 05, 2001 at 10:23 UTC
Yes, both of those work. I didn't use the first one because I already had a shared file handle so no need to create another one. I didn't use the second one because it doesn't allow me to wait; I have to loop sleeping and checking. But they are both good techniques to know. Thanks. - tye (but my friends call me "Tye")	[reply]