File::stat - by-name interface to Perl's built-in stat functions |
File::stat - by-name interface to Perl's built-in stat()
functions
use File::stat; $st = stat($file) or die "No $file: $!"; if ( ($st->mode & 0111) && $st->nlink > 1) ) { print "$file is executable with lotsa links\n"; }
if ( -x $st ) { print "$file is executable\n"; }
use Fcntl "S_IRUSR"; if ( $st->cando(S_IRUSR, 1) ) { print "My effective uid can read $file\n"; }
use File::stat qw(:FIELDS); stat($file) or die "No $file: $!"; if ( ($st_mode & 0111) && ($st_nlink > 1) ) { print "$file is executable with lotsa links\n"; }
This module's default exports override the core stat()
and lstat()
functions, replacing them with versions that return
``File::stat'' objects. This object has methods that
return the similarly named structure field name from the
stat(2)
function; namely,
dev,
ino,
mode,
nlink,
uid,
gid,
rdev,
size,
atime,
mtime,
ctime,
blksize,
and
blocks.
As of version 1.02 (provided with perl 5.12) the object provides "-X"
overloading, so you can call filetest operators (-f
, -x
, and so
on) on it. It also provides a ->cando
method, called like
$st->cando( ACCESS, EFFECTIVE )
where ACCESS is one of S_IRUSR
, S_IWUSR
or S_IXUSR
from the
Fcntl module, and EFFECTIVE indicates whether to use
effective (true) or real (false) ids. The method interprets the mode
,
uid
and gid
fields, and returns whether or not the current process
would be allowed the specified access.
If you don't want to use the objects, you may import the ->cando
method into your namespace as a regular function called stat_cando
.
This takes an arrayref containing the return values of stat
or
lstat
as its first argument, and interprets it for you.
You may also import all the structure fields directly into your namespace
as regular variables using the :FIELDS import tag. (Note that this still
overrides your stat()
and lstat()
functions.) Access these fields as
variables named with a preceding st_
in front their method names.
Thus, $stat_obj->dev()
corresponds to $st_dev if you import
the fields.
To access this functionality without the core overrides,
pass the use
an empty import list, and then access
function functions with their full qualified names.
On the other hand, the built-ins are still available
via the CORE::
pseudo-package.
As of Perl 5.8.0 after using this module you cannot use the implicit
$_
or the special filehandle _
with stat()
or lstat(), trying
to do so leads into strange errors. The workaround is for $_
to
be explicit
my $stat_obj = stat $_;
and for _
to explicitly populate the object using the unexported
and undocumented populate()
function with CORE::stat():
my $stat_obj = File::stat::populate(CORE::stat(_));
-t
, -T
and -B
are not implemented, as
they require more information than just a stat buffer.
These can all be disabled with
no warnings "File::stat";
-rwxRWX
filetests with use
filetest 'access'
in effect. File::stat
will ignore the pragma, and
just use the information in the mode
member as usual.
File::stat
overloads, however,
do not, since the information required is not available.
While this class is currently implemented using the Class::Struct module to build a struct-like class, you shouldn't rely upon this.
Tom Christiansen
File::stat - by-name interface to Perl's built-in stat functions |