diff options
Diffstat (limited to 'pod/perlpacktut.pod')
| -rw-r--r-- | pod/perlpacktut.pod | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/pod/perlpacktut.pod b/pod/perlpacktut.pod index 3b138efe2d..7beee3234a 100644 --- a/pod/perlpacktut.pod +++ b/pod/perlpacktut.pod @@ -176,7 +176,8 @@ template doesn't match the incoming data, Perl will scream and die. Hence, putting it all together: - my($date,$description,$income,$expend) = unpack("A10xA27xA7xA*", $_); + my ($date, $description, $income, $expend) = + unpack("A10xA27xA7xA*", $_); Now, that's our data parsed. I suppose what we might want to do now is total up our income and expenditure, and add another line to the end of @@ -184,7 +185,8 @@ our ledger - in the same format - saying how much we've brought in and how much we've spent: while (<>) { - my($date, $desc, $income, $expend) = unpack("A10xA27xA7xA*", $_); + my ($date, $desc, $income, $expend) = + unpack("A10xA27xA7xA*", $_); $tot_income += $income; $tot_expend += $expend; } @@ -196,7 +198,8 @@ how much we've spent: # OK, let's go: - print pack("A10xA27xA7xA*", $date, "Totals", $tot_income, $tot_expend); + print pack("A10xA27xA7xA*", $date, "Totals", + $tot_income, $tot_expend); Oh, hmm. That didn't quite work. Let's see what happened: @@ -219,7 +222,8 @@ What we actually need to do is expand the width of the fields. The C<A> format pads any non-existent characters with spaces, so we can use the additional spaces to line up our fields, like this: - print pack("A11 A28 A8 A*", $date, "Totals", $tot_income, $tot_expend); + print pack("A11 A28 A8 A*", $date, "Totals", + $tot_income, $tot_expend); (Note that you can put spaces in the template to make it more readable, but they don't translate to spaces in the output.) Here's what we got @@ -238,7 +242,8 @@ can get C<sprintf> to do it: $tot_income = sprintf("%.2f", $tot_income); $tot_expend = sprintf("%12.2f", $tot_expend); $date = POSIX::strftime("%m/%d/%Y", localtime); - print pack("A11 A28 A8 A*", $date, "Totals", $tot_income, $tot_expend); + print pack("A11 A28 A8 A*", $date, "Totals", + $tot_income, $tot_expend); This time we get the right answer: @@ -791,7 +796,8 @@ C</> is not implemented in Perls before 5.6, so if your code is required to work on older Perls you'll need to C<unpack( 'Z* Z* C')> to get the length, then use it to make a new unpack string. For example - # pack a message: ASCIIZ, ASCIIZ, length, string, byte (5.005 compatible) + # pack a message: ASCIIZ, ASCIIZ, length, string, byte + # (5.005 compatible) my $msg = pack( 'Z* Z* C A* C', $src, $dst, length $sm, $sm, $prio ); # unpack |