David <[EMAIL PROTECTED]> wrote:
> Steve Grazzini wrote:
>>
>> And besides, open() is not particularly easy to
>> override. You'd have to account for all of:
>>
>> open FH, $path;
>> open FH, "> $path";
>> open FH, ">", $path;
>> open FH, ">", \$sstream;
>> open FH, "command |";
>> open FH, "| command";
>
> i don't recommand people do all of the above. if
> the need arise to access the open() function that
> came with Perl, CORE::open() is good enough.
Right -- you don't want to implement open(), just
validate the arguments before calling the builtin.
But there are still two issues.
1) Before validating a path, you have to determine
whether you've been passed one, since several
standard forms of open() don't open a regular
file at all.
I left out a few of these:
open FH, "<&stdin"; # dup STDIN
open FH, "<&0"; # ditto
open FH, "-"; # ditto
open FH, "|-"; # fork + pipe
And I've probably *still* forgotten others.
2) You can't break the semantics of the builtin.
This means you have to turn the first argument
(a string, a globref, an undefined scalar, etc)
into a filehandle. And then you need to call
the builtin with the correct number and type of
arguments.
This is also trickier than it appears on first
blush. Look what happens when you try:
use subs qw/open/;
sub open { CORE::open(@_) }
open IN, $0 or die "open: '$0': $!\n";
print while <IN>;
Anyway there's a lot to learn in IPC/Open3.pm
if the OP really wants to do this.
--
Steve
perldoc -qa.j | perl -lpe '($_)=m("(.*)")'
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