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inc/File/Spec/Unix.pm  view on Meta::CPAN

=item devnull

Returns a string representation of the null device. "/dev/null" on UNIX.

=cut

sub devnull () { '/dev/null' }

=item rootdir

Returns a string representation of the root directory.  "/" on UNIX.

=cut

sub rootdir () { '/' }

=item tmpdir

Returns a string representation of the first writable directory from
the following list or the current directory if none from the list are
writable:

    $ENV{TMPDIR}
    /tmp

Since perl 5.8.0, if running under taint mode, and if $ENV{TMPDIR}
is tainted, it is not used.

=cut

my $tmpdir;
sub _tmpdir {
    return $tmpdir if defined $tmpdir;
    my $self = shift;
    my @dirlist = @_;
    {
	no strict 'refs';
	if (${"\cTAINT"}) { # Check for taint mode on perl >= 5.8.0
            require Scalar::Util;
	    @dirlist = grep { ! Scalar::Util::tainted($_) } @dirlist;
	}
    }
    foreach (@dirlist) {
	next unless defined && -d && -w _;
	$tmpdir = $_;
	last;
    }
    $tmpdir = $self->curdir unless defined $tmpdir;
    $tmpdir = defined $tmpdir && $self->canonpath($tmpdir);
    return $tmpdir;
}

sub tmpdir {
    return $tmpdir if defined $tmpdir;
    my $self = shift;
    $tmpdir = $self->_tmpdir( $ENV{TMPDIR}, "/tmp" );
}

=item updir

Returns a string representation of the parent directory.  ".." on UNIX.

=cut

sub updir () { '..' }

=item no_upwards

Given a list of file names, strip out those that refer to a parent
directory. (Does not strip symlinks, only '.', '..', and equivalents.)

=cut

sub no_upwards {
    my $self = shift;
    return grep(!/^\.{1,2}\Z(?!\n)/s, @_);
}

=item case_tolerant

Returns a true or false value indicating, respectively, that alphabetic
is not or is significant when comparing file specifications.

=cut

sub case_tolerant () { 0 }

=item file_name_is_absolute

Takes as argument a path and returns true if it is an absolute path.

This does not consult the local filesystem on Unix, Win32, OS/2 or Mac 
OS (Classic).  It does consult the working environment for VMS (see
L<File::Spec::VMS/file_name_is_absolute>).

=cut

sub file_name_is_absolute {
    my ($self,$file) = @_;
    return scalar($file =~ m:^/:s);
}

=item path

Takes no argument, returns the environment variable PATH as an array.

=cut

sub path {
    return () unless exists $ENV{PATH};
    my @path = split(':', $ENV{PATH});
    foreach (@path) { $_ = '.' if $_ eq '' }
    return @path;
}

=item join

join is the same as catfile.

=cut

sub join {
    my $self = shift;
    return $self->catfile(@_);
}

=item splitpath

    ($volume,$directories,$file) = File::Spec->splitpath( $path );

inc/File/Spec/Unix.pm  view on Meta::CPAN

    $rel_path = File::Spec->abs2rel( $path ) ;
    $rel_path = File::Spec->abs2rel( $path, $base ) ;

If $base is not present or '', then L<cwd()|Cwd> is used. If $base is
relative, then it is converted to absolute form using
L</rel2abs()>. This means that it is taken to be relative to
L<cwd()|Cwd>.

On systems that have a grammar that indicates filenames, this ignores the 
$base filename. Otherwise all path components are assumed to be
directories.

If $path is relative, it is converted to absolute form using L</rel2abs()>.
This means that it is taken to be relative to L<cwd()|Cwd>.

No checks against the filesystem are made.  On VMS, there is
interaction with the working environment, as logicals and
macros are expanded.

Based on code written by Shigio Yamaguchi.

=cut

sub abs2rel {
    my($self,$path,$base) = @_;

    # Clean up $path
    if ( ! $self->file_name_is_absolute( $path ) ) {
        $path = $self->rel2abs( $path ) ;
    }
    else {
        $path = $self->canonpath( $path ) ;
    }

    # Figure out the effective $base and clean it up.
    if ( !defined( $base ) || $base eq '' ) {
        $base = $self->_cwd();
    }
    elsif ( ! $self->file_name_is_absolute( $base ) ) {
        $base = $self->rel2abs( $base ) ;
    }
    else {
        $base = $self->canonpath( $base ) ;
    }

    # Now, remove all leading components that are the same
    my @pathchunks = $self->splitdir( $path);
    my @basechunks = $self->splitdir( $base);

    while (@pathchunks && @basechunks && $pathchunks[0] eq $basechunks[0]) {
        shift @pathchunks ;
        shift @basechunks ;
    }

    $path = CORE::join( '/', @pathchunks );
    $base = CORE::join( '/', @basechunks );

    # $base now contains the directories the resulting relative path 
    # must ascend out of before it can descend to $path_directory.  So, 
    # replace all names with $parentDir
    $base =~ s|[^/]+|..|g ;

    # Glue the two together, using a separator if necessary, and preventing an
    # empty result.
    if ( $path ne '' && $base ne '' ) {
        $path = "$base/$path" ;
    } else {
        $path = "$base$path" ;
    }

    return $self->canonpath( $path ) ;
}

=item rel2abs()

Converts a relative path to an absolute path. 

    $abs_path = File::Spec->rel2abs( $path ) ;
    $abs_path = File::Spec->rel2abs( $path, $base ) ;

If $base is not present or '', then L<cwd()|Cwd> is used. If $base is
relative, then it is converted to absolute form using
L</rel2abs()>. This means that it is taken to be relative to
L<cwd()|Cwd>.

On systems that have a grammar that indicates filenames, this ignores
the $base filename. Otherwise all path components are assumed to be
directories.

If $path is absolute, it is cleaned up and returned using L</canonpath()>.

No checks against the filesystem are made.  On VMS, there is
interaction with the working environment, as logicals and
macros are expanded.

Based on code written by Shigio Yamaguchi.

=cut

sub rel2abs {
    my ($self,$path,$base ) = @_;

    # Clean up $path
    if ( ! $self->file_name_is_absolute( $path ) ) {
        # Figure out the effective $base and clean it up.
        if ( !defined( $base ) || $base eq '' ) {
	    $base = $self->_cwd();
        }
        elsif ( ! $self->file_name_is_absolute( $base ) ) {
            $base = $self->rel2abs( $base ) ;
        }
        else {
            $base = $self->canonpath( $base ) ;
        }

        # Glom them together
        $path = $self->catdir( $base, $path ) ;
    }

    return $self->canonpath( $path ) ;