I didn't write it, and I don't know Perl very well at all.

>>Why not just do it native say like

sysopen($fh, "$dir/$name", O_CREAT | O_EXCL | O_RDWR, 0600);
[download]

Thanks for supplying the code. I don't know why the person wanted to lock the file. Here is a bigger snippet of what is happening, down to the unlink, which I think is like the "unlock" ??

system ("lockfile -2 -r 5 $base_dir/.lock")  == 0
        or diehtml("Lock error: ", $? >> 8, "\n");
        # TODO stop stderr of system

    # create unique suffix
    if (-f "$base_dir/$seq_file") {
        open(SEQ, "+<$base_dir/$seq_file")
            or diehtml("Error opening seq file: $!\n");
        $seq = ;
        seek SEQ, 0, 0;
    } else {
        open(SEQ, ">$base_dir/$seq_file")
            or diehtml("Error creating seq file: $!\n");
        $seq = 0;
    }
    
    $outfile .= sprintf "%7.7d", $seq;
    $ordernumber = $seq;    #store this order no. before 'next' is cal
+c.
    print SEQ ++$seq;
    close SEQ or warn "Something wrong closing seq: $!\n";
    unlink "$base_dir/.lock" or diehtml("Unlock error: $!\n");

    open(ORDERFILE, ">$outfile")
        or diehtml("Can't open order records: $!\n");

    print ORDERFILE @_;
    close ORDERFILE or warn "Something fishy with closing the order: $
+!\n";
}
[download]

The file SEQ, is just a line line ASCII file with the next order number in it.

Peter

I didn't write it, and I don't know Perl very well at all.

We know. Regardless you have come to the right place for help.

The purpose of a lockfile is to tell other processes (ie copies of a CGI) to bugger off and wait their turn.

Anyway here is a pure Perl replacement that is identical to the lockfile call (well it is not IDENTICAL) because this actually works as the system call to lockfile should....

my $got_lock;
use Fcntl;   # to get constants for O_CREAT | O_EXCL | O_RDWR
for ( 0 .. 5 ) {
    if ( sysopen(my $fh, "$base_dir/.lock", O_CREAT | O_EXCL | O_RDWR,
+ 0600) ) {
        $got_lock = 1;
        close $fh;
      last;
    }
    sleep 2;
}
diehtml("Lock error $!\n") unless $got_lock;
[download]

That should be a cut and paste replacement for this:

system ("lockfile -2 -r 5 $base_dir/.lock")  == 0
        or diehtml("Lock error: ", $? >> 8, "\n");
        # TODO stop stderr of system
[download]

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print

Is there a line vaguely like:

while (-e "$base_dir/.lock") {
    sleep 1;
}
[download]

just above the code you have shown us????

Definitely not, no 'while' or 'sleep' code. It's all drop down, except for a few subs.

Thanks for supplying the pure Perl replacement code, I'll try that today. Would I still leave this line the same ?

unlink "$base_dir/.lock" or diehtml("Unlock error: $!\n");
[download]

Thanks a lot,

Peter

I don't know why the person wanted to lock the file.

I actually found a post on comp.lang.perl.misc that was from the guy that wrote it; here is his algorithm:

enter program
while (1)
   look for lockfile
   if lockfile does not exist exit
   sleep 5 seconds
}
create lockfile

..... do normal program stuff ......

unlink lockfile
exit
[download]

However, if the process died before removing the lock, it crashed the web server. The post was 7 years ago, so no doubt what has been suggested here will be _much_ better. :)

Peter

Okay, I will have to leave it until the morning, it's late here (down under), and the pwd for SSH access is on another computer.

Possibly the code needs rewriting anyway. Thanks to you all for your help, ... wow, I have never received such fast responses. :)

Peter

Thanks for sorting out the lockfile problem. I will either use this one you supplied

my $got_lock;
use Fcntl;   # to get constants for O_CREAT | O_EXCL | O_RDWR
for ( 0 .. 5 ) {
    if ( sysopen(my $fh, "$base_dir/.lock", O_CREAT | O_EXCL | O_RDWR,
+ 0600) ) {
        $got_lock = 1;
        close $fh;
      last;
    }
    sleep 2;
}
diehtml("Lock error $!\n") unless $got_lock;
[download]

.. or the "fully blown" lockfile code you supplied in your other post ..You either have to delete it by hand or do something like this:

I consider the lockfile problem sorted out now, thanks. Because of the problems now with "opens", I would to replace code like this:

open(ORDERFILE, ">$outfile")
        or diehtml("Can't open order records: $!\n");
[download]

with (native) code of the format:

sysopen($fh, "$dir/$name", O_CREAT | O_EXCL | O_RDWR, 0600);
[download]

... would it be something like:

$fh = "ORDERFILE";
sysopen($fh, "$outfile", O_CREAT | O_EXCL | O_RDWR, 0600)
        or diehtml("Can't open order records: $!\n");
[download]

Just a wild guess. :)

Peter

No :-)

This code is fine for what it does:

open        # open a file for read or write
(
ORDERFILE  # onto a FILEHANDLE called ORDERFILE
,
"
>          # > means write to the file, create if does not exist
           # Note all previous content will be deleted 
           # if this file exists >> means append to the end
$outfile   # full or relative path to file
"
)
or         # if the open works it returns true so we never do the next
+ bit
diehtml()  # print an error message
[download]

You don't wanna touch anything in the demon code. It was for illustrative purposes and is not relevant to your problem provided you are happy that the code you have worked just replace the lockfile code.

In this code:

$fh = "ORDERFILE";
sysopen($fh, "$outfile", O_CREAT | O_EXCL | O_RDWR, 0600)
        or diehtml("Can't open order records: $!\n");
[download]

You don't need to set $fh to a string. It will just get overwritten in the open. A FILEHANDLE is a type of perl internal object (like a scalar) and the reference to it is held in the $fh var. To illustrate the syntax:

open $fh, ">$file" or die "Can't write $file $!\n";
print $fh "here is some data\n";
close $fh;
[download]

Same with sysopen but I can't be bothered to type that much.

cheers

tachyon

s&&rsenoyhcatreve&&&s&n.+t&"$'$`$\"$\&"&ee&&y&srve&&d&&print