=head1 NAME
-perlfaq5 - Files and Formats ($Revision: 1.1 $, $Date: 2001/09/20 03:03:00 $)
+perlfaq5 - Files and Formats ($Revision: 1.4 $, $Date: 2001/11/09 08:06:04 $)
=head1 DESCRIPTION
$document = join('', <$sock>);
print "DOC IS: $document\n";
-Note the bizarrely hardcoded carriage return and newline in their octal
+Note the bizarrely hard coded carriage return and newline in their octal
equivalents. This is the ONLY way (currently) to assure a proper flush
on all platforms, including Macintosh. That's the way things work in
network programming: you really should specify the exact bit pattern
We've used C<$$var> in a way that forbidden by C<use strict 'refs'>.
That is, we've promoted a string to a scalar variable reference using
-symbolic references. This is ok in small programs, but doesn't scale
+symbolic references. This is okay in small programs, but doesn't scale
well. It also only works on global variables, not lexicals.
=head2 How can I make a filehandle local to a subroutine? How do I pass filehandles between subroutines? How do I make an array of filehandles?
before using it. That is because only simple scalar variables, not
expressions or subscripts of hashes or arrays, can be used with
built-ins like C<print>, C<printf>, or the diamond operator. Using
-something other than a simple scalar varaible as a filehandle is
+something other than a simple scalar variable as a filehandle is
illegal and won't even compile:
@fd = (*STDIN, *STDOUT, *STDERR);
This one will do it for you:
sub commify {
- local $_ = shift;
- 1 while s/^([-+]?\d+)(\d{3})/$1,$2/;
- return $_;
+ my $number = shift;
+ 1 while ($number =~ s/^([-+]?\d+)(\d{3})/$1,$2/);
+ return $number;
}
$n = 23659019423.2331;
does implement append mode correctly (a local filesystem on a modern
Unix for example), and you keep the file in block-buffered mode and you
write less than one buffer-full of output between each manual flushing
-of the buffer then each bufferload is almost garanteed to be written to
+of the buffer then each bufferload is almost guaranteed to be written to
the end of the file in one chunk without getting intermingled with
anyone else's output. You can also use the syswrite() function which is
simply a wrapper around your systems write(2) system call.
If you want to retrieve the time at which the file was last read,
written, or had its meta-data (owner, etc) changed, you use the B<-M>,
-B<-A>, or B<-C> filetest operations as documented in L<perlfunc>. These
+B<-A>, or B<-C> file test operations as documented in L<perlfunc>. These
retrieve the age of the file (measured against the start-time of your
program) in days as a floating point number. To retrieve the "raw"
time in seconds since the epoch, you would call the stat function,
Otherwise you'll have to write your own multiplexing print
function--or your own tee program--or use Tom Christiansen's,
-at http://www.perl.com/CPAN/authors/id/TOMC/scripts/tct.gz , which is
+at http://www.cpan.org/authors/id/TOMC/scripts/tct.gz , which is
written in Perl and offers much greater functionality
than the stock version.
% ./fionread
0x4004667f
-And then hard-code it, leaving porting as an exercise to your successor.
+And then hard code it, leaving porting as an exercise to your successor.
$FIONREAD = 0x4004667f; # XXX: opsys dependent
This is elaborately and painstakingly described in the "Far More Than
You Ever Wanted To Know" in
-http://www.perl.com/CPAN/doc/FMTEYEWTK/file-dir-perms .
+http://www.cpan.org/doc/FMTEYEWTK/file-dir-perms .
The executive summary: learn how your filesystem works. The
permissions on a file say what can happen to the data in that file.
projects / p5sagit/p5-mst-13.2.git / blobdiff