Monty Taylor wrote:
> open(FOO,'<foo.txt');
> @LIST=['FOO','.bashrc'];
> while (<@LIST>) {
> process;
> }
>
> and a directory containing the files FOO, foo.txt, and .bashrc
>
> Does <@LIST> treat FOO as a filehandle or a filename? Or maybe this
> would be clearer...
I am assuming that bareword filehandles will go away (see discussion of
RFC 10 and RFC 14). The files './FOO' and './.bashrc' will be
processed. 'foo.txt' will not as ref 'FOO' ne 'GLOB'.
> open(LOG,'>/tmp/output.log');
> opendir(FOO,'.');
> @dir=readdir FOO;
> while (<@dir> ) {
> process;
> }
>
> and a directory having files 'FOO','STDOUT','STDIN' and 'LOG'. Do we
> treat as filehandles or files?
Only the files in '.' will be processed. Try out the code I posted in
the IMPLEMENTATION section - it works under perl 5.6.
> I agree, it's streching for an example, but I hope the question is
> clear?
In v2 of RFC 51, I intend to point out that filehandles can be
completely hidden from the user:
my $file = '/path/to/file';
print $file; # prints filename
print <$file>; # prints contents of the file
I will also propose extending the syntax to include directories:
my @homefiles = grep (-f, <'~'>); # list of plain files
print <@homefiles>; # cat ~/*
Under this scheme, _all_ scalars are potential filehandles. Think of
them as symlinks. As soon as you apply the <> operator to a scalar,
perl should open it in a DWIM fashion and give you back the next line
(in scalar context) or a list of lines (in list context) from the file.
The next time you use <> on that scalar, perl should give you the next
line or undef if there are no more lines to read. Most scripts won't
need to explicitly call open() any more.
my $file1 = '/path/to/file';
<$file1>; # read and discard one line
my $file2 = $file1; # copy the filehandle to $file2
print <$file2>; # print all but the first line
print <$file1>; # print nothing (end of file)
$file2 = scalar $file3; # copy filename
print <$file2>; # print entire file (new filehandle)
Jon
--
Knowledge is that which remains when what is
learned is forgotten. - Mr. King
