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- package File::stat;
- use 5.006;
- use strict;
- use warnings;
- use warnings::register;
- use Carp;
- BEGIN { *warnif = \&warnings::warnif }
- our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS);
- our $VERSION = '1.07';
- my @fields;
- BEGIN {
- use Exporter ();
- @EXPORT = qw(stat lstat);
- @fields = qw( $st_dev $st_ino $st_mode
- $st_nlink $st_uid $st_gid
- $st_rdev $st_size
- $st_atime $st_mtime $st_ctime
- $st_blksize $st_blocks
- );
- @EXPORT_OK = ( @fields, "stat_cando" );
- %EXPORT_TAGS = ( FIELDS => [ @fields, @EXPORT ] );
- }
- use vars @fields;
- use Fcntl qw(S_IRUSR S_IWUSR S_IXUSR);
- BEGIN {
- # These constants will croak on use if the platform doesn't define
- # them. It's important to avoid inflicting that on the user.
- no strict 'refs';
- for (qw(suid sgid svtx)) {
- my $val = eval { &{"Fcntl::S_I\U$_"} };
- *{"_$_"} = defined $val ? sub { $_[0] & $val ? 1 : "" } : sub { "" };
- }
- for (qw(SOCK CHR BLK REG DIR LNK)) {
- *{"S_IS$_"} = defined eval { &{"Fcntl::S_IF$_"} }
- ? \&{"Fcntl::S_IS$_"} : sub { "" };
- }
- # FIFO flag and macro don't quite follow the S_IF/S_IS pattern above
- # RT #111638
- *{"S_ISFIFO"} = defined &Fcntl::S_IFIFO
- ? \&Fcntl::S_ISFIFO : sub { "" };
- }
- # from doio.c
- sub _ingroup {
- my ($gid, $eff) = @_;
- # I am assuming that since VMS doesn't have getgroups(2), $) will
- # always only contain a single entry.
- $^O eq "VMS" and return $_[0] == $);
- my ($egid, @supp) = split " ", $);
- my ($rgid) = split " ", $(;
- $gid == ($eff ? $egid : $rgid) and return 1;
- grep $gid == $_, @supp and return 1;
- return "";
- }
- # VMS uses the Unix version of the routine, even though this is very
- # suboptimal. VMS has a permissions structure that doesn't really fit
- # into struct stat, and unlike on Win32 the normal -X operators respect
- # that, but unfortunately by the time we get here we've already lost the
- # information we need. It looks to me as though if we were to preserve
- # the st_devnam entry of vmsish.h's fake struct stat (which actually
- # holds the filename) it might be possible to do this right, but both
- # getting that value out of the struct (perl's stat doesn't return it)
- # and interpreting it later would require this module to have an XS
- # component (at which point we might as well just call Perl_cando and
- # have done with it).
-
- if (grep $^O eq $_, qw/os2 MSWin32 dos/) {
- # from doio.c
- *cando = sub { ($_[0][2] & $_[1]) ? 1 : "" };
- }
- else {
- # from doio.c
- *cando = sub {
- my ($s, $mode, $eff) = @_;
- my $uid = $eff ? $> : $<;
- my ($stmode, $stuid, $stgid) = @$s[2,4,5];
- # This code basically assumes that the rwx bits of the mode are
- # the 0777 bits, but so does Perl_cando.
- if ($uid == 0 && $^O ne "VMS") {
- # If we're root on unix
- # not testing for executable status => all file tests are true
- return 1 if !($mode & 0111);
- # testing for executable status =>
- # for a file, any x bit will do
- # for a directory, always true
- return 1 if $stmode & 0111 || S_ISDIR($stmode);
- return "";
- }
- if ($stuid == $uid) {
- $stmode & $mode and return 1;
- }
- elsif (_ingroup($stgid, $eff)) {
- $stmode & ($mode >> 3) and return 1;
- }
- else {
- $stmode & ($mode >> 6) and return 1;
- }
- return "";
- };
- }
- # alias for those who don't like objects
- *stat_cando = \&cando;
- my %op = (
- r => sub { cando($_[0], S_IRUSR, 1) },
- w => sub { cando($_[0], S_IWUSR, 1) },
- x => sub { cando($_[0], S_IXUSR, 1) },
- o => sub { $_[0][4] == $> },
- R => sub { cando($_[0], S_IRUSR, 0) },
- W => sub { cando($_[0], S_IWUSR, 0) },
- X => sub { cando($_[0], S_IXUSR, 0) },
- O => sub { $_[0][4] == $< },
- e => sub { 1 },
- z => sub { $_[0][7] == 0 },
- s => sub { $_[0][7] },
- f => sub { S_ISREG ($_[0][2]) },
- d => sub { S_ISDIR ($_[0][2]) },
- l => sub { S_ISLNK ($_[0][2]) },
- p => sub { S_ISFIFO($_[0][2]) },
- S => sub { S_ISSOCK($_[0][2]) },
- b => sub { S_ISBLK ($_[0][2]) },
- c => sub { S_ISCHR ($_[0][2]) },
- u => sub { _suid($_[0][2]) },
- g => sub { _sgid($_[0][2]) },
- k => sub { _svtx($_[0][2]) },
- M => sub { ($^T - $_[0][9] ) / 86400 },
- C => sub { ($^T - $_[0][10]) / 86400 },
- A => sub { ($^T - $_[0][8] ) / 86400 },
- );
- use constant HINT_FILETEST_ACCESS => 0x00400000;
- # we need fallback=>1 or stringifying breaks
- use overload
- fallback => 1,
- -X => sub {
- my ($s, $op) = @_;
- if (index("rwxRWX", $op) >= 0) {
- (caller 0)[8] & HINT_FILETEST_ACCESS
- and warnif("File::stat ignores use filetest 'access'");
- $^O eq "VMS" and warnif("File::stat ignores VMS ACLs");
- # It would be nice to have a warning about using -l on a
- # non-lstat, but that would require an extra member in the
- # object.
- }
- if ($op{$op}) {
- return $op{$op}->($_[0]);
- }
- else {
- croak "-$op is not implemented on a File::stat object";
- }
- };
- # Class::Struct forbids use of @ISA
- sub import { goto &Exporter::import }
- use Class::Struct qw(struct);
- struct 'File::stat' => [
- map { $_ => '$' } qw{
- dev ino mode nlink uid gid rdev size
- atime mtime ctime blksize blocks
- }
- ];
- sub populate (@) {
- return unless @_;
- my $stob = new();
- @$stob = (
- $st_dev, $st_ino, $st_mode, $st_nlink, $st_uid, $st_gid, $st_rdev,
- $st_size, $st_atime, $st_mtime, $st_ctime, $st_blksize, $st_blocks )
- = @_;
- return $stob;
- }
- sub lstat ($) { populate(CORE::lstat(shift)) }
- sub stat ($) {
- my $arg = shift;
- my $st = populate(CORE::stat $arg);
- return $st if defined $st;
- my $fh;
- {
- local $!;
- no strict 'refs';
- require Symbol;
- $fh = \*{ Symbol::qualify( $arg, caller() )};
- return unless defined fileno $fh;
- }
- return populate(CORE::stat $fh);
- }
- 1;
- __END__
- =head1 NAME
- File::stat - by-name interface to Perl's built-in stat() functions
- =head1 SYNOPSIS
- 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";
- }
- =head1 DESCRIPTION
- 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 C<"-X">
- overloading, so you can call filetest operators (C<-f>, C<-x>, and so
- on) on it. It also provides a C<< ->cando >> method, called like
- $st->cando( ACCESS, EFFECTIVE )
- where I<ACCESS> is one of C<S_IRUSR>, C<S_IWUSR> or C<S_IXUSR> from the
- L<Fcntl|Fcntl> module, and I<EFFECTIVE> indicates whether to use
- effective (true) or real (false) ids. The method interprets the C<mode>,
- C<uid> and C<gid> fields, and returns whether or not the current process
- would be allowed the specified access.
- If you don't want to use the objects, you may import the C<< ->cando >>
- method into your namespace as a regular function called C<stat_cando>.
- This takes an arrayref containing the return values of C<stat> or
- C<lstat> as its first argument, and interprets it for you.
- You may also import all the structure fields directly into your namespace
- as regular variables using the :FIELDS import tag. (Note that this still
- overrides your stat() and lstat() functions.) Access these fields as
- variables named with a preceding C<st_> in front their method names.
- Thus, C<$stat_obj-E<gt>dev()> corresponds to $st_dev if you import
- the fields.
- To access this functionality without the core overrides,
- pass the C<use> an empty import list, and then access
- function functions with their full qualified names.
- On the other hand, the built-ins are still available
- via the C<CORE::> pseudo-package.
- =head1 BUGS
- As of Perl 5.8.0 after using this module you cannot use the implicit
- C<$_> or the special filehandle C<_> with stat() or lstat(), trying
- to do so leads into strange errors. The workaround is for C<$_> to
- be explicit
- my $stat_obj = stat $_;
- and for C<_> to explicitly populate the object using the unexported
- and undocumented populate() function with CORE::stat():
- my $stat_obj = File::stat::populate(CORE::stat(_));
- =head1 ERRORS
- =over 4
- =item -%s is not implemented on a File::stat object
- The filetest operators C<-t>, C<-T> and C<-B> are not implemented, as
- they require more information than just a stat buffer.
- =back
- =head1 WARNINGS
- These can all be disabled with
- no warnings "File::stat";
- =over 4
- =item File::stat ignores use filetest 'access'
- You have tried to use one of the C<-rwxRWX> filetests with C<use
- filetest 'access'> in effect. C<File::stat> will ignore the pragma, and
- just use the information in the C<mode> member as usual.
- =item File::stat ignores VMS ACLs
- VMS systems have a permissions structure that cannot be completely
- represented in a stat buffer, and unlike on other systems the builtin
- filetest operators respect this. The C<File::stat> overloads, however,
- do not, since the information required is not available.
- =back
- =head1 NOTE
- While this class is currently implemented using the Class::Struct
- module to build a struct-like class, you shouldn't rely upon this.
- =head1 AUTHOR
- Tom Christiansen
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