FFI::C::Stat

Object-oriented FFI interface to native stat and lstat

SYNOPSIS

use FFI::C::Stat;

my $stat = FFI::C::Stat->new("foo.txt");
print "size = ", $stat->size;

DESCRIPTION

Perl comes with perfectly good stat, lstat functions, however if you are writing FFI bindings for a library that use the C stat structure, you are out of luck there. This module provides an FFI friendly interface to the C stat function, which uses an object similar to File::stat, except the internals are a real C struct that you can pass into C APIs that need it.

Supposing you have a C function:

void
my_cfunction(struct stat *s)
{
  ...
}

You can bind my_cfunction like this:

use FFI::Platypus 1.00;

my $ffi = FFI::Platypus->new( api => 1 );
$ffi->type('object(FFI::C::Stat)' => 'stat');
$ffi->attach( my_cfunction => ['stat'] => 'void' );

CONSTRUCTORS

new

my $stat = FFI::C::Stat->new(*HANDLE,   %options);
my $stat = FFI::C::Stat->new($filename, %options);
my $stat = FFI::C::Stat->new;

You can create a new instance of this class by calling the new method and passing in either a file or directory handle, or by passing in the filename path. If you do not pass anything then an uninitialized stat will be returned.

Options:

• symlink

  Use lstat instead of stat, that is if the filename is a symlink, stat the symlink instead of the target.

clone

my $stat = FFI::C::Stat->clone($other_stat);

Creates a clone of $stat. The argument $stat can be either a FFI::C::Stat instance, or an opaque pointer to a stat structure. The latter case is helpful when writing bindings to a method that returns a stat structure, since you won't be wanting to free the pointer that belongs to the callee.

C:

struct stat *
my_cfunction()
{
  static struct stat stat;  /* definitely do not want to free static memory */
  ...
  return stat;
}

Perl:

$ffi->attach( my_cfunction => [] => 'opaque' => sub {
  my $xsub = shift;
  my $ptr = $xsub->();
  return FFI::C::Stat->clone($ptr);
});

The behavior of passing in undef prior to version 0.03 was undefined and could cause a crash. In version 0.03 and later passing in undef will return a stat object with all of the bits set to zero (0).

PROPERTIES

dev

my $id = $stat->dev;

The ID of device containing file.

ino

my $inode = $stat->ino;

The inode number.

mode

my $mode = $stat->mode;

The file type and mode.

nlink

my $n = $stat->nlink;

The number of hard links.

uid

my $uid = $stat->uid;

The User ID owner.

gid

my $gid = $stat->gid;

The Group ID owner.

rdev

my $id = $stat->rdev;

The ID of device (if special file)

size

my $size = $stat->size;

Returns the size of the file in bytes.

atime

my $time = $stat->atime;

The time of last access.

mtime

my $time = $stat->mtime;

The time of last modification.

ctime

my $time = $stat->ctime;

The time of last status change.

blksize

my $size = $stat->blksize;

The filesystem-specific preferred I/O block size.

blocks

my $count = $stat->blocks;

Number of blocks allocated.

AUTHOR

Graham Ollis [email protected]

COPYRIGHT AND LICENSE

This software is copyright (c) 2021-2023 by Graham Ollis.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.