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| package File::stat; | |
| use 5.006; | |
| use strict; | |
| use warnings; | |
| use warnings::register; | |
| use Carp; | |
| use constant _IS_CYGWIN => $^O eq "cygwin"; | |
| BEGIN { *warnif = \&warnings::warnif } | |
| our(@EXPORT, @EXPORT_OK, %EXPORT_TAGS); | |
| our $VERSION = '1.09'; | |
| our @fields; | |
| our ( $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 | |
| ); | |
| 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 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 (_IS_CYGWIN ? _ingroup(544, $eff) : ($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 | |