* Ovid <[EMAIL PROTECTED]> [2007-04-16 12:55]:
> Ugh. I hated my double call to stat().
>
> $ENV{PATH} = do {
> my $sep = $Config{path_sep};
>
> join $sep, (
> map { /(.*)/ }
> grep {
> local $_ = stat $_;
> defined && !( $_->mode & S_IWOTH )
> }
> grep { file_name_is_absolute($_) }
> split( /\Q$sep/, $ENV{PATH}, -1 ),
> );
> };
Note that `local $_` has issues when tieing or other magic are
involved. If you want to topicalise something, use `for` instead.
That’s not viable in this case, though, since `for` doesn’t
return a well-defined value and you need that for `grep`. Better
just use a lexical variable.
Also note that if `stat` succeeds it will return an object, which
can never be false. Testing definedness is therefore unnecessary,
you can just test truth.
Finally, if you switch to the low-precedence boolops you can get
rid of those parens. At that point you have the version I posted.
What I learned from this excercise is that Perl has no good API
to encapsulate stat(2). What I *wanted* to write is this:
$s and $s->perm( 'o-w' )
where the `o-w` is a string that follows symbolic chmod mode
syntax. (So `o-w` means “others may not write”, `o+w` means
“others may write”, and `o=w` means “others may write, but not
read or execute,” and you can equally use variations on the theme
like `ug+rx,o=x`.)
That is much easier to decipher than all that C-ish bitfiddle.
Regards,
--
Aristotle Pagaltzis // <http://plasmasturm.org/>
