You are not checking for fork failures.
Worse: xnous does check for fork failures, but way too late:
if (my $pid = fork) { # $pid defined and !=0 -->parent
++$forkcount;
} else { # $pid==0 -->child
open my $IN, '<', $infile or exit(0);
open my $OUT, '>', "$tempdir/$subdir/text-$i" or exit(0);
while (<$IN>) {
tr/-!"#%&()*',.\/:;?@\[\\\]”_“{’}><^)(|/ /; # no punct "
s/^/ /;
s/\n/ \n/;
s/[[:digit:]]{1,12}//g;
s/w(as|ere)/be/gi;
s{$re2}{ $prefix{lc $1} }g; # prefix
s{$re3}{ $substring{lc $1} }g; # part
s{$re1}{ $whole{lc $1} }g; # whole
print $OUT "$_";
}
close $OUT;
close $IN;
defined $pid and exit(0); # $pid==0 -->child, must exit itself
}
If fork() fails, $pid is undef, which is false. So perl will enter the else block, do everything that a child process does, but in the parent process. During that time, the entire child process management (i.e. $forkcount and wait/waitpid) does not happen. The check for failed fork() vs. real child (defined $pid) happens after the child code has run in the parent process. And it lacks any diagnostics.
When I use fork(), I usually write forking code like this:
my $pid=fork() // die "Can't fork: $!";
if ($pid) {
# parent code
} else {
# child code
}
Before Perl had the defined-or operator //, I used the following two lines instead of the first one.
my $pid=fork();
defined($pid) or die "Can't fork: $!";
Alexander
--
Today I will gladly share my knowledge and experience, for there are no sweeter words than "I told you so". ;-)
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