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From: Justin C on 11 Aug 2010 04:17
On 2010-08-10, PerlFAQ Server <brian(a)theperlreview.com> wrote:

[snip]

The code example in the original is over 80 columns wide and could be
easier to follow - especially in ye olde slrn in an 80 column terminal.
I've reformatted it, perhaps $FAQ_maintainer may consider the change?

> Anyway, this is what you can do if you can't help yourself.
>
> use Fcntl qw(:DEFAULT :flock);
> sysopen my $fh, "numfile", O_RDWR|O_CREAT
> or die "can't open numfile: $!";
> flock $fh, LOCK_EX
> or die "can't flock numfile: $!";
> my $num = <$fh> || 0;
> seek $fh, 0, 0
> or die "can't rewind numfile: $!";
> truncate $fh, 0
> or die "can't truncate numfile: $!";
> (print $fh $num+1, "\n")
> or die "can't write numfile: $!";
> close $fh
> or die "can't close numfile: $!";

Justin.

--
Justin C, by the sea.
From: Ben Morrow on 11 Aug 2010 06:41

Quoth Justin C <justin.1007(a)purestblue.com>:
> On 2010-08-10, PerlFAQ Server <brian(a)theperlreview.com> wrote:
>
> The code example in the original is over 80 columns wide and could be
> easier to follow - especially in ye olde slrn in an 80 column terminal.

Ooh, yes, that's nasty. I rather suspect someone's gone trawling through
the docs adding 'or die' everywhere without thinking too hard about the
formatting.

> I've reformatted it, perhaps $FAQ_maintainer may consider the change?
>
> > Anyway, this is what you can do if you can't help yourself.
> >
> > use Fcntl qw(:DEFAULT :flock);
> > sysopen my $fh, "numfile", O_RDWR|O_CREAT
> > or die "can't open numfile: $!";
> > flock $fh, LOCK_EX
> > or die "can't flock numfile: $!";
> > my $num = <$fh> || 0;
> > seek $fh, 0, 0
> > or die "can't rewind numfile: $!";
> > truncate $fh, 0
> > or die "can't truncate numfile: $!";
> > (print $fh $num+1, "\n")
> > or die "can't write numfile: $!";
> > close $fh
> > or die "can't close numfile: $!";

Since autodie has been core since 5.10, this would seem like a perfect
place to use it. I don't know what the FAQ's policy is on things like
that (myself, I'm starting to seriously consider adding 'autodie' to
'warnings' and 'strict' as something I always have on).

Ben

From: David Canzi on 12 Aug 2010 15:42
In article <8bbaj7-89u1.ln1(a)osiris.mauzo.dyndns.org>,
Ben Morrow <ben(a)morrow.me.uk> wrote:
>
>Quoth Justin C <justin.1007(a)purestblue.com>:
>> On 2010-08-10, PerlFAQ Server <brian(a)theperlreview.com> wrote:
>>
>> The code example in the original is over 80 columns wide and could be
>> easier to follow - especially in ye olde slrn in an 80 column terminal.
>
>Ooh, yes, that's nasty. I rather suspect someone's gone trawling through
>the docs adding 'or die' everywhere without thinking too hard about the
>formatting.
>
>> I've reformatted it, perhaps $FAQ_maintainer may consider the change?
>>
>> > Anyway, this is what you can do if you can't help yourself.
>> >
>> > use Fcntl qw(:DEFAULT :flock);
>> > sysopen my $fh, "numfile", O_RDWR|O_CREAT
>> > or die "can't open numfile: $!";
>> > flock $fh, LOCK_EX
>> > or die "can't flock numfile: $!";
>> > my $num = <$fh> || 0;
>> > seek $fh, 0, 0
>> > or die "can't rewind numfile: $!";
>> > truncate $fh, 0
>> > or die "can't truncate numfile: $!";
>> > (print $fh $num+1, "\n")
>> > or die "can't write numfile: $!";
>> > close $fh
>> > or die "can't close numfile: $!";
>
>Since autodie has been core since 5.10, this would seem like a perfect
>place to use it. I don't know what the FAQ's policy is on things like
>that (myself, I'm starting to seriously consider adding 'autodie' to
>'warnings' and 'strict' as something I always have on).

Advice and example code in the FAQs should be useful to typical
perl users, who run the version of perl that came with their
operating system. A quick scan of about 100 machines in my work
environment didn't find any running perl 5.10.

--
David Canzi | "If the human mind were simple enough for us to understand,
| we would be too simple-minded to understand it." -- anonymous
 | 
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