File::Basename - Parse file paths into directory, filename and suffix.

perl documentation Contained in the perl distribution.

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NAME

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File::Basename - Parse file paths into directory, filename and suffix.

SYNOPSIS

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    use File::Basename;

    ($name,$path,$suffix) = fileparse($fullname,@suffixlist);
    $name = fileparse($fullname,@suffixlist);

    $basename = basename($fullname,@suffixlist);
    $dirname  = dirname($fullname);

DESCRIPTION

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These routines allow you to parse file paths into their directory, filename and suffix.

NOTE: dirname() and basename() emulate the behaviours, and quirks, of the shell and C functions of the same name. See each function's documentation for details. If your concern is just parsing paths it is safer to use File::Spec's splitpath() and splitdir() methods.

It is guaranteed that

    # Where $path_separator is / for Unix, \ for Windows, etc...
    dirname($path) . $path_separator . basename($path);

is equivalent to the original path for all systems but VMS.

fileparse fileparse
    my($filename, $directories, $suffix) = fileparse($path);
    my($filename, $directories, $suffix) = fileparse($path, @suffixes);
    my $filename                         = fileparse($path, @suffixes);

The fileparse() routine divides a file path into its $directories, $filename and (optionally) the filename $suffix.

$directories contains everything up to and including the last directory separator in the $path including the volume (if applicable). The remainder of the $path is the $filename.

     # On Unix returns ("baz", "/foo/bar/", "")
     fileparse("/foo/bar/baz");

     # On Windows returns ("baz", "C:\foo\bar\", "")
     fileparse("C:\foo\bar\baz");

     # On Unix returns ("", "/foo/bar/baz/", "")
     fileparse("/foo/bar/baz/");

If @suffixes are given each element is a pattern (either a string or a qr//) matched against the end of the $filename. The matching portion is removed and becomes the $suffix.

     # On Unix returns ("baz", "/foo/bar/", ".txt")
     fileparse("/foo/bar/baz.txt", qr/\.[^.]*/);

If type is non-Unix (see fileparse_set_fstype()) then the pattern matching for suffix removal is performed case-insensitively, since those systems are not case-sensitive when opening existing files.

You are guaranteed that $directories . $filename . $suffix will denote the same location as the original $path.

basename basename filename
    my $filename = basename($path);
    my $filename = basename($path, @suffixes);

This function is provided for compatibility with the Unix shell command basename(1). It does NOT always return the file name portion of a path as you might expect. To be safe, if you want the file name portion of a path use fileparse().

basename() returns the last level of a filepath even if the last level is clearly directory. In effect, it is acting like pop() for paths. This differs from fileparse()'s behaviour.

    # Both return "bar"
    basename("/foo/bar");
    basename("/foo/bar/");

@suffixes work as in fileparse() except all regex metacharacters are quoted.

    # These two function calls are equivalent.
    my $filename = basename("/foo/bar/baz.txt",  ".txt");
    my $filename = fileparse("/foo/bar/baz.txt", qr/\Q.txt\E/);

Also note that in order to be compatible with the shell command, basename() does not strip off a suffix if it is identical to the remaining characters in the filename.

dirname dirname

This function is provided for compatibility with the Unix shell command dirname(1) and has inherited some of its quirks. In spite of its name it does NOT always return the directory name as you might expect. To be safe, if you want the directory name of a path use fileparse().

Only on VMS (where there is no ambiguity between the file and directory portions of a path) and AmigaOS (possibly due to an implementation quirk in this module) does dirname() work like fileparse($path), returning just the $directories.

    # On VMS and AmigaOS
    my $directories = dirname($path);

When using Unix or MSDOS syntax this emulates the dirname(1) shell function which is subtly different from how fileparse() works. It returns all but the last level of a file path even if the last level is clearly a directory. In effect, it is not returning the directory portion but simply the path one level up acting like chop() for file paths.

Also unlike fileparse(), dirname() does not include a trailing slash on its returned path.

    # returns /foo/bar.  fileparse() would return /foo/bar/
    dirname("/foo/bar/baz");

    # also returns /foo/bar despite the fact that baz is clearly a 
    # directory.  fileparse() would return /foo/bar/baz/
    dirname("/foo/bar/baz/");

    # returns '.'.  fileparse() would return 'foo/'
    dirname("foo/");

Under VMS, if there is no directory information in the $path, then the current default device and directory is used.

fileparse_set_fstype filesystem
  my $type = fileparse_set_fstype();
  my $previous_type = fileparse_set_fstype($type);

Normally File::Basename will assume a file path type native to your current operating system (ie. /foo/bar style on Unix, \foo\bar on Windows, etc...). With this function you can override that assumption.

Valid $types are "MacOS", "VMS", "AmigaOS", "OS2", "RISCOS", "MSWin32", "DOS" (also "MSDOS" for backwards bug compatibility), "Epoc" and "Unix" (all case-insensitive). If an unrecognized $type is given "Unix" will be assumed.

If you've selected VMS syntax, and the file specification you pass to one of these routines contains a "/", they assume you are using Unix emulation and apply the Unix syntax rules instead, for that function call only.

SEE ALSO

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dirname(1), basename(1), File::Spec

perl documentation Contained in the perl distribution. 

package File::Basename;

# A bit of juggling to insure that C<use re 'taint';> always works, since
# File::Basename is used during the Perl build, when the re extension may
# not be available.
BEGIN {
  unless (eval { require re; })
    { eval ' sub re::import { $^H |= 0x00100000; } ' } # HINT_RE_TAINT
  import re 'taint';
}


use strict;
use 5.006;
use warnings;
our(@ISA, @EXPORT, $VERSION, $Fileparse_fstype, $Fileparse_igncase);
require Exporter;
@ISA = qw(Exporter);
@EXPORT = qw(fileparse fileparse_set_fstype basename dirname);
$VERSION = "2.77";

fileparse_set_fstype($^O);




sub fileparse {
  my($fullname,@suffices) = @_;

  unless (defined $fullname) {
      require Carp;
      Carp::croak("fileparse(): need a valid pathname");
  }

  my $orig_type = '';
  my($type,$igncase) = ($Fileparse_fstype, $Fileparse_igncase);

  my($taint) = substr($fullname,0,0);  # Is $fullname tainted?

  if ($type eq "VMS" and $fullname =~ m{/} ) {
    # We're doing Unix emulation
    $orig_type = $type;
    $type = 'Unix';
  }

  my($dirpath, $basename);

  if (grep { $type eq $_ } qw(MSDOS DOS MSWin32 Epoc)) {
    ($dirpath,$basename) = ($fullname =~ /^((?:.*[:\\\/])?)(.*)/s);
    $dirpath .= '.\\' unless $dirpath =~ /[\\\/]\z/;
  }
  elsif ($type eq "OS2") {
    ($dirpath,$basename) = ($fullname =~ m#^((?:.*[:\\/])?)(.*)#s);
    $dirpath = './' unless $dirpath;	# Can't be 0
    $dirpath .= '/' unless $dirpath =~ m#[\\/]\z#;
  }
  elsif ($type eq "MacOS") {
    ($dirpath,$basename) = ($fullname =~ /^(.*:)?(.*)/s);
    $dirpath = ':' unless $dirpath;
  }
  elsif ($type eq "AmigaOS") {
    ($dirpath,$basename) = ($fullname =~ /(.*[:\/])?(.*)/s);
    $dirpath = './' unless $dirpath;
  }
  elsif ($type eq 'VMS' ) {
    ($dirpath,$basename) = ($fullname =~ /^(.*[:>\]])?(.*)/s);
    $dirpath ||= '';  # should always be defined
  }
  else { # Default to Unix semantics.
    ($dirpath,$basename) = ($fullname =~ m{^(.*/)?(.*)}s);
    if ($orig_type eq 'VMS' and $fullname =~ m{^(/[^/]+/000000(/|$))(.*)}) {
      # dev:[000000] is top of VMS tree, similar to Unix '/'
      # so strip it off and treat the rest as "normal"
      my $devspec  = $1;
      my $remainder = $3;
      ($dirpath,$basename) = ($remainder =~ m{^(.*/)?(.*)}s);
      $dirpath ||= '';  # should always be defined
      $dirpath = $devspec.$dirpath;
    }
    $dirpath = './' unless $dirpath;
  }
      

  my $tail   = '';
  my $suffix = '';
  if (@suffices) {
    foreach $suffix (@suffices) {
      my $pat = ($igncase ? '(?i)' : '') . "($suffix)\$";
      if ($basename =~ s/$pat//s) {
        $taint .= substr($suffix,0,0);
        $tail = $1 . $tail;
      }
    }
  }

  # Ensure taint is propgated from the path to its pieces.
  $tail .= $taint;
  wantarray ? ($basename .= $taint, $dirpath .= $taint, $tail)
            : ($basename .= $taint);
}





sub basename {
  my($path) = shift;

  # From BSD basename(1)
  # The basename utility deletes any prefix ending with the last slash `/'
  # character present in string (after first stripping trailing slashes)
  _strip_trailing_sep($path);

  my($basename, $dirname, $suffix) = fileparse( $path, map("\Q$_\E",@_) );

  # From BSD basename(1)
  # The suffix is not stripped if it is identical to the remaining 
  # characters in string.
  if( length $suffix and !length $basename ) {
      $basename = $suffix;
  }
  
  # Ensure that basename '/' == '/'
  if( !length $basename ) {
      $basename = $dirname;
  }

  return $basename;
}





sub dirname {
    my $path = shift;

    my($type) = $Fileparse_fstype;

    if( $type eq 'VMS' and $path =~ m{/} ) {
        # Parse as Unix
        local($File::Basename::Fileparse_fstype) = '';
        return dirname($path);
    }

    my($basename, $dirname) = fileparse($path);

    if ($type eq 'VMS') { 
        $dirname ||= $ENV{DEFAULT};
    }
    elsif ($type eq 'MacOS') {
	if( !length($basename) && $dirname !~ /^[^:]+:\z/) {
            _strip_trailing_sep($dirname);
	    ($basename,$dirname) = fileparse $dirname;
	}
	$dirname .= ":" unless $dirname =~ /:\z/;
    }
    elsif (grep { $type eq $_ } qw(MSDOS DOS MSWin32 OS2)) { 
        _strip_trailing_sep($dirname);
        unless( length($basename) ) {
	    ($basename,$dirname) = fileparse $dirname;
	    _strip_trailing_sep($dirname);
	}
    }
    elsif ($type eq 'AmigaOS') {
        if ( $dirname =~ /:\z/) { return $dirname }
        chop $dirname;
        $dirname =~ s{[^:/]+\z}{} unless length($basename);
    }
    else {
        _strip_trailing_sep($dirname);
        unless( length($basename) ) {
	    ($basename,$dirname) = fileparse $dirname;
	    _strip_trailing_sep($dirname);
	}
    }

    $dirname;
}


# Strip the trailing path separator.
sub _strip_trailing_sep  {
    my $type = $Fileparse_fstype;

    if ($type eq 'MacOS') {
        $_[0] =~ s/([^:]):\z/$1/s;
    }
    elsif (grep { $type eq $_ } qw(MSDOS DOS MSWin32 OS2)) { 
        $_[0] =~ s/([^:])[\\\/]*\z/$1/;
    }
    else {
        $_[0] =~ s{(.)/*\z}{$1}s;
    }
}




BEGIN {

my @Ignore_Case = qw(MacOS VMS AmigaOS OS2 RISCOS MSWin32 MSDOS DOS Epoc);
my @Types = (@Ignore_Case, qw(Unix));

sub fileparse_set_fstype {
    my $old = $Fileparse_fstype;

    if (@_) {
        my $new_type = shift;

        $Fileparse_fstype = 'Unix';  # default
        foreach my $type (@Types) {
            $Fileparse_fstype = $type if $new_type =~ /^$type/i;
        }

        $Fileparse_igncase = 
          (grep $Fileparse_fstype eq $_, @Ignore_Case) ? 1 : 0;
    }

    return $old;
}

}


1;