package File::Find; use 5.006; use strict; use warnings; use warnings::register; our $VERSION = '1.43'; use Exporter 'import'; require Cwd;
our @EXPORT = qw(find finddepth);
use strict; my $Is_VMS = $^O eq 'VMS'; my $Is_Win32 = $^O eq 'MSWin32';
require File::Basename; require File::Spec;
# Should ideally be my() not our() but local() currently # refuses to operate on lexicals
our %SLnkSeen; our ($wanted_callback, $avoid_nlink, $bydepth, $no_chdir, $follow, $follow_skip, $full_check, $untaint, $untaint_skip, $untaint_pat, $pre_process, $post_process, $dangling_symlinks);
sub contract_name { my ($cdir,$fn) = @_;
return substr($cdir,0,rindex($cdir,'/')) if $fn eq $File::Find::current_dir;
$cdir = substr($cdir,0,rindex($cdir,'/')+1);
$fn =~ s|^\./||;
my $abs_name= $cdir . $fn;
if (substr($fn,0,3) eq '../') {
1 while $abs_name =~ s!/[^/]*/\.\./+!/!;
}
return $abs_name;
}sub _is_absolute { return $_[0] =~ m|^(?:[A-Za-z]:)?/| if $Is_Win32; return substr($_[0], 0, 1) eq '/'; }
sub _is_root { return $_[0] =~ m|^(?:[A-Za-z]:)?/\z| if $Is_Win32; return $_[0] eq '/'; }
sub PathCombine($$) { my ($Base,$Name) = @_; my $AbsName;
if (_is_absolute($Name)) {
$AbsName= $Name;
}
else {
$AbsName= contract_name($Base,$Name);
}
# (simple) check for recursion
my $newlen= length($AbsName);
if ($newlen <= length($Base)) {
if (($newlen == length($Base) || substr($Base,$newlen,1) eq '/')
&& $AbsName eq substr($Base,0,$newlen))
{
return undef;
}
}
return $AbsName;
}sub Follow_SymLink($) { my ($AbsName) = @_;
my ($NewName,$DEV, $INO);
($DEV, $INO)= lstat $AbsName;
while (-l _) {
if ($SLnkSeen{$DEV, $INO}++) {
if ($follow_skip < 2) {
die "$AbsName is encountered a second time";
}
else {
return undef;
}
}
my $Link = readlink($AbsName);
# canonicalize directory separators
$Link =~ s|\\|/|g if $Is_Win32;
$NewName= PathCombine($AbsName, $Link);
unless(defined $NewName) {
if ($follow_skip < 2) {
die "$AbsName is a recursive symbolic link";
}
else {
return undef;
}
}
else {
$AbsName= $NewName;
}
($DEV, $INO) = lstat($AbsName);
return undef unless defined $DEV; # dangling symbolic link
}
if ($full_check && defined $DEV && $SLnkSeen{$DEV, $INO}++) {
if ( ($follow_skip < 1) || ((-d _) && ($follow_skip < 2)) ) {
die "$AbsName encountered a second time";
}
else {
return undef;
}
}
return $AbsName;
}our($dir, $name, $fullname, $prune); sub _find_dir_symlnk($$$); sub _find_dir($$$);
# check whether or not a scalar variable is tainted # (code straight from the Camel, 3rd ed., page 561) sub is_tainted_pp { my $arg = shift; my $nada = substr($arg, 0, 0); # zero-length local $@; eval { eval "# $nada" }; return length($@) != 0; }
sub _find_opt { my $wanted = shift; return unless @_; die "invalid top directory" unless defined $_[0];
# This function must local()ize everything because callbacks may
# call find() or finddepth()
local %SLnkSeen;
local ($wanted_callback, $avoid_nlink, $bydepth, $no_chdir, $follow,
$follow_skip, $full_check, $untaint, $untaint_skip, $untaint_pat,
$pre_process, $post_process, $dangling_symlinks);
local($dir, $name, $fullname, $prune);
local *_ = \my $a;
my $cwd = $wanted->{bydepth} ? Cwd::fastcwd() : Cwd::getcwd();
if ($Is_VMS) {
# VMS returns this by default in VMS format which just doesn't
# work for the rest of this module.
$cwd = VMS::Filespec::unixpath($cwd);
# Apparently this is not expected to have a trailing space.
# To attempt to make VMS/UNIX conversions mostly reversible,
# a trailing slash is needed. The run-time functions ignore the
# resulting double slash, but it causes the perl tests to fail.
$cwd =~ s#/\z##;
# This comes up in upper case now, but should be lower.
# In the future this could be exact case, no need to change.
}
my $cwd_untainted = $cwd;
my $check_t_cwd = 1;
$wanted_callback = $wanted->{wanted};
$bydepth = $wanted->{bydepth};
$pre_process = $wanted->{preprocess};
$post_process = $wanted->{postprocess};
$no_chdir = $wanted->{no_chdir};
$full_check = $wanted->{follow};
$follow = $full_check || $wanted->{follow_fast};
$follow_skip = $wanted->{follow_skip};
$untaint = $wanted->{untaint};
$untaint_pat = $wanted->{untaint_pattern};
$untaint_skip = $wanted->{untaint_skip};
$dangling_symlinks = $wanted->{dangling_symlinks};
# for compatibility reasons (find.pl, find2perl)
local our ($topdir, $topdev, $topino, $topmode, $topnlink);
# a symbolic link to a directory doesn't increase the link count
$avoid_nlink = $follow || $File::Find::dont_use_nlink;
my ($abs_dir, $Is_Dir);
Proc_Top_Item:
foreach my $TOP (@_) {
my $top_item = $TOP;
$top_item = VMS::Filespec::unixify($top_item) if $Is_VMS;
($topdev,$topino,$topmode,$topnlink) = $follow ? stat $top_item : lstat $top_item;
# canonicalize directory separators
$top_item =~ s|[/\\]|/|g if $Is_Win32;
# no trailing / unless path is root
$top_item =~ s|/\z|| unless _is_root($top_item);
$Is_Dir= 0;
if ($follow) {
if (_is_absolute($top_item)) {
$abs_dir = $top_item;
}
elsif ($top_item eq $File::Find::current_dir) {
$abs_dir = $cwd;
}
else { # care about any ../
$top_item =~ s/\.dir\z//i if $Is_VMS;
$abs_dir = contract_name("$cwd/",$top_item);
}
$abs_dir= Follow_SymLink($abs_dir);
unless (defined $abs_dir) {
if ($dangling_symlinks) {
if (ref $dangling_symlinks eq 'CODE') {
$dangling_symlinks->($top_item, $cwd);
} else {
warnings::warnif "$top_item is a dangling symbolic link\n";
}
}
next Proc_Top_Item;
}
if (-d _) {
$top_item =~ s/\.dir\z//i if $Is_VMS;
_find_dir_symlnk($wanted, $abs_dir, $top_item);
$Is_Dir= 1;
}
}
else { # no follow
$topdir = $top_item;
unless (defined $topnlink) {
warnings::warnif "Can't stat $top_item: $!\n";
next Proc_Top_Item;
}
if (-d _) {
$top_item =~ s/\.dir\z//i if $Is_VMS;
_find_dir($wanted, $top_item, $topnlink);
$Is_Dir= 1;
}
else {
$abs_dir= $top_item;
}
}
unless ($Is_Dir) {
unless (($_,$dir) = File::Basename::fileparse($abs_dir)) {
($dir,$_) = ('./', $top_item);
}
$abs_dir = $dir;
if (( $untaint ) && (is_tainted($dir) )) {
( $abs_dir ) = $dir =~ m|$untaint_pat|;
unless (defined $abs_dir) {
if ($untaint_skip == 0) {
die "directory $dir is still tainted";
}
else {
next Proc_Top_Item;
}
}
}
unless ($no_chdir || chdir $abs_dir) {
warnings::warnif "Couldn't chdir $abs_dir: $!\n";
next Proc_Top_Item;
}
$name = $abs_dir . $_; # $File::Find::name
$_ = $name if $no_chdir;
{ $wanted_callback->() }; # protect against wild "next"
}
unless ( $no_chdir ) {
if ( ($check_t_cwd) && (($untaint) && (is_tainted($cwd) )) ) {
( $cwd_untainted ) = $cwd =~ m|$untaint_pat|;
unless (defined $cwd_untainted) {
die "insecure cwd in find(depth)";
}
$check_t_cwd = 0;
}
unless (chdir $cwd_untainted) {
die "Can't cd to $cwd: $!\n";
}
}
}
}# API: # $wanted # $p_dir : "parent directory" # $nlink : what came back from the stat # preconditions: # chdir (if not no_chdir) to dir
sub _find_dir($$$) { my ($wanted, $p_dir, $nlink) = @_; my ($CdLvl,$Level) = (0,0); my @Stack; my @filenames; my ($subcount,$sub_nlink); my $SE= []; my $dir_name= $p_dir; my $dir_pref; my $dir_rel = $File::Find::current_dir; my $tainted = 0; my $no_nlink;
if ($Is_VMS) {
# VMS is returning trailing .dir on directories
# and trailing . on files and symbolic links
# in UNIX syntax.
#
$p_dir =~ s/\.(dir)?$//i unless $p_dir eq '.';
$dir_pref = ($p_dir =~ m/[\]>]+$/ ? $p_dir : "$p_dir/" );
}
else {
$dir_pref = _is_root($p_dir) ? $p_dir : "$p_dir/";
}
local ($dir, $name, $prune);
unless ( $no_chdir || ($p_dir eq $File::Find::current_dir)) {
my $udir = $p_dir;
if (( $untaint ) && (is_tainted($p_dir) )) {
( $udir ) = $p_dir =~ m|$untaint_pat|;
unless (defined $udir) {
if ($untaint_skip == 0) {
die "directory $p_dir is still tainted";
}
else {
return;
}
}
}
unless (chdir ($Is_VMS && $udir !~ /[\/\[<]+/ ? "./$udir" : $udir)) {
warnings::warnif "Can't cd to $udir: $!\n";
return;
}
}
# push the starting directory
push @Stack,[$CdLvl,$p_dir,$dir_rel,-1] if $bydepth;
while (defined $SE) {
unless ($bydepth) {
$dir= $p_dir; # $File::Find::dir
$name= $dir_name; # $File::Find::name
$_= ($no_chdir ? $dir_name : $dir_rel ); # $_
# prune may happen here
$prune= 0;
{ $wanted_callback->() }; # protect against wild "next"
next if $prune;
}
# change to that directory
unless ($no_chdir || ($dir_rel eq $File::Find::current_dir)) {
my $udir= $dir_rel;
if ( ($untaint) && (($tainted) || ($tainted = is_tainted($dir_rel) )) ) {
( $udir ) = $dir_rel =~ m|$untaint_pat|;
unless (defined $udir) {
if ($untaint_skip == 0) {
die "directory (" . ($p_dir ne '/' ? $p_dir : '') . "/) $dir_rel is still tainted";
} else { # $untaint_skip == 1
next;
}
}
}
unless (chdir ($Is_VMS && $udir !~ /[\/\[<]+/ ? "./$udir" : $udir)) {
warnings::warnif "Can't cd to (" .
($p_dir ne '/' ? $p_dir : '') . "/) $udir: $!\n";
next;
}
$CdLvl++;
}
$dir= $dir_name; # $File::Find::dir
# Get the list of files in the current directory.
my $dh;
unless (opendir $dh, ($no_chdir ? $dir_name : $File::Find::current_dir)) {
warnings::warnif "Can't opendir($dir_name): $!\n";
next;
}
@filenames = readdir $dh;
closedir($dh);
@filenames = $pre_process->(@filenames) if $pre_process;
push @Stack,[$CdLvl,$dir_name,"",-2] if $post_process;
# default: use whatever was specified
# (if $nlink >= 2, and $avoid_nlink == 0, this will switch back)
$no_nlink = $avoid_nlink;
# if dir has wrong nlink count, force switch to slower stat method
$no_nlink = 1 if ($nlink < 2);
if ($nlink == 2 && !$no_nlink) {
# This dir has no subdirectories.
for my $FN (@filenames) {
if ($Is_VMS) {
# Big hammer here - Compensate for VMS trailing . and .dir
# No win situation until this is changed, but this
# will handle the majority of the cases with breaking the fewest
$FN =~ s/\.dir\z//i;
$FN =~ s#\.$## if ($FN ne '.');
}
next if $FN =~ $File::Find::skip_pattern;
$name = $dir_pref . $FN; # $File::Find::name
$_ = ($no_chdir ? $name : $FN); # $_
{ $wanted_callback->() }; # protect against wild "next"
}
}
else {
# This dir has subdirectories.
$subcount = $nlink - 2;
# HACK: insert directories at this position, so as to preserve
# the user pre-processed ordering of files (thus ensuring
# directory traversal is in user sorted order, not at random).
my $stack_top = @Stack;
for my $FN (@filenames) {
next if $FN =~ $File::Find::skip_pattern;
if ($subcount > 0 || $no_nlink) {
# Seen all the subdirs?
# check for directoriness.
# stat is faster for a file in the current directory
$sub_nlink = (lstat ($no_chdir ? $dir_pref . $FN : $FN))[3];
if (-d _) {
--$subcount;
$FN =~ s/\.dir\z//i if $Is_VMS;
# HACK: replace push to preserve dir traversal order
#push @Stack,[$CdLvl,$dir_name,$FN,$sub_nlink];
splice @Stack, $stack_top, 0,
[$CdLvl,$dir_name,$FN,$sub_nlink];
}
else {
$name = $dir_pref . $FN; # $File::Find::name
$_= ($no_chdir ? $name : $FN); # $_
{ $wanted_callback->() }; # protect against wild "next"
}
}
else {
$name = $dir_pref . $FN; # $File::Find::name
$_= ($no_chdir ? $name : $FN); # $_
{ $wanted_callback->() }; # protect against wild "next"
}
}
}
}
continue {
while ( defined ($SE = pop @Stack) ) {
($Level, $p_dir, $dir_rel, $nlink) = @$SE;
if ($CdLvl > $Level && !$no_chdir) {
my $tmp;
if ($Is_VMS) {
$tmp = '[' . ('-' x ($CdLvl-$Level)) . ']';
}
else {
$tmp = join('/',('..') x ($CdLvl-$Level));
}
die "Can't cd to $tmp from $dir_name: $!"
unless chdir ($tmp);
$CdLvl = $Level;
}
if ($^O eq 'VMS') {
if ($p_dir =~ m/[\]>]+$/) {
$dir_name = $p_dir;
$dir_name =~ s/([\]>]+)$/.$dir_rel$1/;
$dir_pref = $dir_name;
}
else {
$dir_name = "$p_dir/$dir_rel";
$dir_pref = "$dir_name/";
}
}
else {
$dir_name = _is_root($p_dir) ? "$p_dir$dir_rel" : "$p_dir/$dir_rel";
$dir_pref = "$dir_name/";
}
if ( $nlink == -2 ) {
$name = $dir = $p_dir; # $File::Find::name / dir
$_ = $File::Find::current_dir;
$post_process->(); # End-of-directory processing
}
elsif ( $nlink < 0 ) { # must be finddepth, report dirname now
$name = $dir_name;
if ( substr($name,-2) eq '/.' ) {
substr($name, length($name) == 2 ? -1 : -2) = '';
}
$dir = $p_dir;
$_ = ($no_chdir ? $dir_name : $dir_rel );
if ( substr($_,-2) eq '/.' ) {
substr($_, length($_) == 2 ? -1 : -2) = '';
}
{ $wanted_callback->() }; # protect against wild "next"
}
else {
push @Stack,[$CdLvl,$p_dir,$dir_rel,-1] if $bydepth;
last;
}
}
}
}# API: # $wanted # $dir_loc : absolute location of a dir # $p_dir : "parent directory" # preconditions: # chdir (if not no_chdir) to dir
sub _find_dir_symlnk($$$) { my ($wanted, $dir_loc, $p_dir) = @_; # $dir_loc is the absolute directory my @Stack; my @filenames; my $new_loc; my $updir_loc = $dir_loc; # untainted parent directory my $SE = []; my $dir_name = $p_dir; my $dir_pref; my $loc_pref; my $dir_rel = $File::Find::current_dir; my $byd_flag; # flag for pending stack entry if $bydepth my $tainted = 0; my $ok = 1;
$dir_pref = _is_root($p_dir) ? $p_dir : "$p_dir/";
$loc_pref = _is_root($dir_loc) ? $dir_loc : "$dir_loc/";
local ($dir, $name, $fullname, $prune);
unless ($no_chdir) {
# untaint the topdir
if (( $untaint ) && (is_tainted($dir_loc) )) {
( $updir_loc ) = $dir_loc =~ m|$untaint_pat|; # parent dir, now untainted
# once untainted, $updir_loc is pushed on the stack (as parent directory);
# hence, we don't need to untaint the parent directory every time we chdir
# to it later
unless (defined $updir_loc) {
if ($untaint_skip == 0) {
die "directory $dir_loc is still tainted";
}
else {
return;
}
}
}
$ok = chdir($updir_loc) unless ($p_dir eq $File::Find::current_dir);
unless ($ok) {
warnings::warnif "Can't cd to $updir_loc: $!\n";
return;
}
}
push @Stack,[$dir_loc,$updir_loc,$p_dir,$dir_rel,-1] if $bydepth;
while (defined $SE) {
unless ($bydepth) {
# change (back) to parent directory (always untainted)
unless ($no_chdir) {
unless (chdir $updir_loc) {
warnings::warnif "Can't cd to $updir_loc: $!\n";
next;
}
}
$dir= $p_dir; # $File::Find::dir
$name= $dir_name; # $File::Find::name
$_= ($no_chdir ? $dir_name : $dir_rel ); # $_
$fullname= $dir_loc; # $File::Find::fullname
# prune may happen here
$prune= 0;
lstat($_); # make sure file tests with '_' work
{ $wanted_callback->() }; # protect against wild "next"
next if $prune;
}
# change to that directory
unless ($no_chdir || ($dir_rel eq $File::Find::current_dir)) {
$updir_loc = $dir_loc;
if ( ($untaint) && (($tainted) || ($tainted = is_tainted($dir_loc) )) ) {
# untaint $dir_loc, what will be pushed on the stack as (untainted) parent dir
( $updir_loc ) = $dir_loc =~ m|$untaint_pat|;
unless (defined $updir_loc) {
if ($untaint_skip == 0) {
die "directory $dir_loc is still tainted";
}
else {
next;
}
}
}
unless (chdir $updir_loc) {
warnings::warnif "Can't cd to $updir_loc: $!\n";
next;
}
}
$dir = $dir_name; # $File::Find::dir
# Get the list of files in the current directory.
my $dh;
unless (opendir $dh, ($no_chdir ? $dir_loc : $File::Find::current_dir)) {
warnings::warnif "Can't opendir($dir_loc): $!\n";
next;
}
@filenames = readdir $dh;
closedir($dh);
for my $FN (@filenames) {
if ($Is_VMS) {
# Big hammer here - Compensate for VMS trailing . and .dir
# No win situation until this is changed, but this
# will handle the majority of the cases with breaking the fewest.
$FN =~ s/\.dir\z//i;
$FN =~ s#\.$## if ($FN ne '.');
}
next if $FN =~ $File::Find::skip_pattern;
# follow symbolic links / do an lstat
$new_loc = Follow_SymLink($loc_pref.$FN);
# ignore if invalid symlink
unless (defined $new_loc) {
if (!defined -l _ && $dangling_symlinks) {
$fullname = undef;
if (ref $dangling_symlinks eq 'CODE') {
$dangling_symlinks->($FN, $dir_pref);
} else {
warnings::warnif "$dir_pref$FN is a dangling symbolic link\n";
}
}
else {
$fullname = $loc_pref . $FN;
}
$name = $dir_pref . $FN;
$_ = ($no_chdir ? $name : $FN);
{ $wanted_callback->() };
next;
}
if (-d _) {
if ($Is_VMS) {
$FN =~ s/\.dir\z//i;
$FN =~ s#\.$## if ($FN ne '.');
$new_loc =~ s/\.dir\z//i;
$new_loc =~ s#\.$## if ($new_loc ne '.');
}
push @Stack,[$new_loc,$updir_loc,$dir_name,$FN,1];
}
else {
$fullname = $new_loc; # $File::Find::fullname
$name = $dir_pref . $FN; # $File::Find::name
$_ = ($no_chdir ? $name : $FN); # $_
{ $wanted_callback->() }; # protect against wild "next"
}
}
}
continue {
while (defined($SE = pop @Stack)) {
($dir_loc, $updir_loc, $p_dir, $dir_rel, $byd_flag) = @$SE;
$dir_name = _is_root($p_dir) ? "$p_dir$dir_rel" : "$p_dir/$dir_rel";
$dir_pref = "$dir_name/";
$loc_pref = "$dir_loc/";
if ( $byd_flag < 0 ) { # must be finddepth, report dirname now
unless ($no_chdir || ($dir_rel eq $File::Find::current_dir)) {
unless (chdir $updir_loc) { # $updir_loc (parent dir) is always untainted
warnings::warnif "Can't cd to $updir_loc: $!\n";
next;
}
}
$fullname = $dir_loc; # $File::Find::fullname
$name = $dir_name; # $File::Find::name
if ( substr($name,-2) eq '/.' ) {
substr($name, length($name) == 2 ? -1 : -2) = ''; # $File::Find::name
}
$dir = $p_dir; # $File::Find::dir
$_ = ($no_chdir ? $dir_name : $dir_rel); # $_
if ( substr($_,-2) eq '/.' ) {
substr($_, length($_) == 2 ? -1 : -2) = '';
}
lstat($_); # make sure file tests with '_' work
{ $wanted_callback->() }; # protect against wild "next"
}
else {
push @Stack,[$dir_loc, $updir_loc, $p_dir, $dir_rel,-1] if $bydepth;
last;
}
}
}
}sub wrap_wanted { my $wanted = shift; if ( ref($wanted) eq 'HASH' ) { # RT #122547 my %valid_options = map {$_ => 1} qw( wanted bydepth preprocess postprocess follow follow_fast follow_skip dangling_symlinks no_chdir untaint untaint_pattern untaint_skip ); my @invalid_options = (); for my $v (keys %{$wanted}) { push @invalid_options, $v unless exists $valid_options{$v}; } warn "Invalid option(s): @invalid_options" if @invalid_options;
unless( exists $wanted->{wanted} and ref( $wanted->{wanted} ) eq 'CODE' ) {
die 'no &wanted subroutine given';
}
if ( $wanted->{follow} || $wanted->{follow_fast}) {
$wanted->{follow_skip} = 1 unless defined $wanted->{follow_skip};
}
if ( $wanted->{untaint} ) {
$wanted->{untaint_pattern} = $File::Find::untaint_pattern
unless defined $wanted->{untaint_pattern};
$wanted->{untaint_skip} = 0 unless defined $wanted->{untaint_skip};
}
return $wanted;
}
elsif( ref( $wanted ) eq 'CODE' ) {
return { wanted => $wanted };
}
else {
die 'no &wanted subroutine given';
}
}sub find { my $wanted = shift; _find_opt(wrap_wanted($wanted), @_); }
sub finddepth { my $wanted = wrap_wanted(shift); $wanted->{bydepth} = 1; _find_opt($wanted, @_); }
# default $File::Find::skip_pattern = qr/^\.{1,2}\z/; $File::Find::untaint_pattern = qr|^([-+@\w./]+)$|;
# this _should_ work properly on all platforms # where File::Find can be expected to work $File::Find::current_dir = File::Spec->curdir || '.';
$File::Find::dont_use_nlink = 1;
# We need a function that checks if a scalar is tainted. Either use the # Scalar::Util module's tainted() function or our (slower) pure Perl # fallback is_tainted_pp() { local $@; eval { require Scalar::Util }; *is_tainted = $@ ? \&is_tainted_pp : \&Scalar::Util::tainted; }
1;
__END__
NAME
File::Find - Traverse a directory tree.
SYNOPSIS
use File::Find;
find(\&wanted, @directories_to_search);
sub wanted { ... }
use File::Find;
finddepth(\&wanted, @directories_to_search);
sub wanted { ... }
use File::Find;
find({ wanted => \&process, follow => 1 }, '.');DESCRIPTION
These are functions for searching through directory trees doing work on each file found similar to the Unix find command. File::Find exports two functions, find and finddepth. They work similarly but have subtle differences.
- find
-
find(\&wanted, @directories); find(\%options, @directories);find()does a depth-first search over the given@directoriesin the order they are given. For each file or directory found, it calls the&wantedsubroutine. (See below for details on how to use the&wantedfunction). Additionally, for each directory found, it willchdir()into that directory and continue the search, invoking the&wantedfunction on each file or subdirectory in the directory. - finddepth
-
finddepth(\&wanted, @directories); finddepth(\%options, @directories);finddepth()works just likefind()except that it invokes the&wantedfunction for a directory after invoking it for the directory's contents. It does a postorder traversal instead of a preorder traversal, working from the bottom of the directory tree up wherefind()works from the top of the tree down.
Despite the name of the finddepth() function, both find() and finddepth() perform a depth-first search of the directory hierarchy.
%options
The first argument to find() is either a code reference to your &wanted function, or a hash reference describing the operations to be performed for each file. The code reference is described in "The wanted function" below.
Here are the possible keys for the hash:
wanted-
The value should be a code reference. This code reference is described in "The wanted function" below. The
&wantedsubroutine is mandatory. bydepth-
Reports the name of a directory only AFTER all its entries have been reported. Entry point
finddepth()is a shortcut for specifying{ bydepth => 1 }in the first argument offind(). preprocess-
The value should be a code reference. This code reference is used to preprocess the current directory. The name of the currently processed directory is in
$File::Find::dir. Your preprocessing function is called afterreaddir(), but before the loop that calls thewanted()function. It is called with a list of strings (actually file/directory names) and is expected to return a list of strings. The code can be used to sort the file/directory names alphabetically, numerically, or to filter out directory entries based on their name alone. When follow or follow_fast are in effect,preprocessis a no-op. postprocess-
The value should be a code reference. It is invoked just before leaving the currently processed directory. It is called in void context with no arguments. The name of the current directory is in
$File::Find::dir. This hook is handy for summarizing a directory, such as calculating its disk usage. When follow or follow_fast are in effect,postprocessis a no-op. follow-
Causes symbolic links to be followed. Since directory trees with symbolic links (followed) may contain files more than once and may even have cycles, a hash has to be built up with an entry for each file. This might be expensive both in space and time for a large directory tree. See "follow_fast" and "follow_skip" below. If either follow or follow_fast is in effect:
It is guaranteed that an lstat has been called before the user's
wanted()function is called. This enables fast file checks involving_. Note that this guarantee no longer holds if follow or follow_fast are not set.There is a variable
$File::Find::fullnamewhich holds the absolute pathname of the file with all symbolic links resolved. If the link is a dangling symbolic link, then fullname will be set toundef.
follow_fast-
This is similar to follow except that it may report some files more than once. It does detect cycles, however. Since only symbolic links have to be hashed, this is much cheaper both in space and time. If processing a file more than once (by the user's
wanted()function) is worse than just taking time, the option follow should be used. follow_skip-
follow_skip==1, which is the default, causes all files which are neither directories nor symbolic links to be ignored if they are about to be processed a second time. If a directory or a symbolic link are about to be processed a second time, File::Find dies.follow_skip==0causes File::Find to die if any file is about to be processed a second time.follow_skip==2causes File::Find to ignore any duplicate files and directories but to proceed normally otherwise. dangling_symlinks-
Specifies what to do with symbolic links whose target doesn't exist. If true and a code reference, will be called with the symbolic link name and the directory it lives in as arguments. Otherwise, if true and warnings are on, a warning of the form
"symbolic_link_name is a dangling symbolic link\n"will be issued. If false, the dangling symbolic link will be silently ignored. no_chdir-
Does not
chdir()to each directory as it recurses. Thewanted()function will need to be aware of this, of course. In this case,$_will be the same as$File::Find::name. untaint-
If find is used in taint-mode (-T command line switch or if EUID != UID or if EGID != GID), then internally directory names have to be untainted before they can be
chdir'd to. Therefore they are checked against a regular expression untaint_pattern. Note that all names passed to the user'swanted()function are still tainted. If this option is used while not in taint-mode,untaintis a no-op. untaint_pattern-
See above. This should be set using the
qrquoting operator. The default is set toqr|^([-+@\w./]+)$|. Note that the parentheses are vital. untaint_skip-
If set, a directory which fails the untaint_pattern is skipped, including all its sub-directories. The default is to
diein such a case.
The wanted function
The wanted() function does whatever verifications you want on each file and directory. Note that despite its name, the wanted() function is a generic callback function, and does not tell File::Find if a file is "wanted" or not. In fact, its return value is ignored.
The wanted function takes no arguments but rather does its work through a collection of variables.
$File::Find::diris the current directory name,$_is the current filename within that directory$File::Find::nameis the complete pathname to the file.
The above variables have all been localized and may be changed without affecting data outside of the wanted function.
For example, when examining the file /some/path/foo.ext you will have:
$File::Find::dir = /some/path/
$_ = foo.ext
$File::Find::name = /some/path/foo.extYou are chdir()'d to $File::Find::dir when the function is called, unless no_chdir was specified. Note that when changing to directories is in effect, the root directory (/) is a somewhat special case inasmuch as the concatenation of $File::Find::dir, '/' and $_ is not literally equal to $File::Find::name. The table below summarizes all variants:
$File::Find::name $File::Find::dir $_
default / / .
no_chdir=>0 /etc / etc
/etc/x /etc x
no_chdir=>1 / / /
/etc / /etc
/etc/x /etc /etc/xWhen follow or follow_fast are in effect, there is also a $File::Find::fullname. The function may set $File::Find::prune to prune the tree unless bydepth was specified. Unless follow or follow_fast is specified, for compatibility reasons (find.pl, find2perl) there are in addition the following globals available: $File::Find::topdir, $File::Find::topdev, $File::Find::topino, $File::Find::topmode and $File::Find::topnlink.
This library is useful for the find2perl tool (distributed as part of the App-find2perl CPAN distribution), which when fed,
find2perl / -name .nfs\* -mtime +7 \
-exec rm -f {} \; -o -fstype nfs -pruneproduces something like:
sub wanted {
/^\.nfs.*\z/s &&
(($dev, $ino, $mode, $nlink, $uid, $gid) = lstat($_)) &&
int(-M _) > 7 &&
unlink($_)
||
($nlink || (($dev, $ino, $mode, $nlink, $uid, $gid) = lstat($_))) &&
$dev < 0 &&
($File::Find::prune = 1);
}Notice the _ in the above int(-M _): the _ is a magical filehandle that caches the information from the preceding stat(), lstat(), or filetest.
Here's another interesting wanted function. It will find all symbolic links that don't resolve:
sub wanted {
-l && !-e && print "bogus link: $File::Find::name\n";
}Note that you may mix directories and (non-directory) files in the list of directories to be searched by the wanted() function.
find(\&wanted, "./foo", "./bar", "./baz/epsilon");In the example above, no file in ./baz/ other than ./baz/epsilon will be evaluated by wanted().
See also the script pfind on CPAN for a nice application of this module.
WARNINGS
If you run your program with the -w switch, or if you use the warnings pragma, File::Find will report warnings for several weird situations. You can disable these warnings by putting the statement
no warnings 'File::Find';in the appropriate scope. See warnings for more info about lexical warnings.
BUGS AND CAVEATS
- $dont_use_nlink
-
You can set the variable
$File::Find::dont_use_nlinkto 0 if you are sure the filesystem you are scanning reflects the number of subdirectories in the parent directory'snlinkcount.If you do set
$File::Find::dont_use_nlinkto 0, you may notice an improvement in speed at the risk of not recursing into subdirectories if a filesystem doesn't populatenlinkas expected.$File::Find::dont_use_nlinknow defaults to 1 on all platforms. - symlinks
-
Be aware that the option to follow symbolic links can be dangerous. Depending on the structure of the directory tree (including symbolic links to directories) you might traverse a given (physical) directory more than once (only if
follow_fastis in effect). Furthermore, deleting or changing files in a symbolically linked directory might cause very unpleasant surprises, since you delete or change files in an unknown directory.
HISTORY
File::Find used to produce incorrect results if called recursively. During the development of perl 5.8 this bug was fixed. The first fixed version of File::Find was 1.01.
SEE ALSO
find(1), find2perl.