package File::Find; use 5.006; use strict; use warnings; use warnings::register; our $VERSION = '1.39'; require Exporter; require Cwd; our @ISA = qw(Exporter); 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 PathCombine($$) { my ($Base,$Name) = @_; my $AbsName; if (substr($Name,0,1) eq '/') { $AbsName= $Name; } else { $AbsName= contract_name($Base,$Name); } # (simple) check for recursion my $newlen= length($AbsName); if ($newlen <= length($Base)) { if (($newlen == length($Base) || substr($Base,$newlen,1) eq '/') && $AbsName eq substr($Base,0,$newlen)) { return undef; } } return $AbsName; } sub Follow_SymLink($) { my ($AbsName) = @_; my ($NewName,$DEV, $INO); ($DEV, $INO)= lstat $AbsName; while (-l _) { if ($SLnkSeen{$DEV, $INO}++) { if ($follow_skip < 2) { die "$AbsName is encountered a second time"; } else { return undef; } } $NewName= PathCombine($AbsName, readlink($AbsName)); unless(defined $NewName) { if ($follow_skip < 2) { die "$AbsName is a recursive symbolic link"; } else { return undef; } } else { $AbsName= $NewName; } ($DEV, $INO) = lstat($AbsName); return undef unless defined $DEV; # dangling symbolic link } if ($full_check && defined $DEV && $SLnkSeen{$DEV, $INO}++) { if ( ($follow_skip < 1) || ((-d _) && ($follow_skip < 2)) ) { die "$AbsName encountered a second time"; } else { return undef; } } return $AbsName; } our($dir, $name, $fullname, $prune); sub _find_dir_symlnk($$$); 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; if ($Is_Win32) { $top_item =~ s|[/\\]\z|| unless $top_item =~ m{^(?:\w:)?[/\\]$}; } else { $top_item =~ s|/\z|| unless $top_item eq '/'; } $Is_Dir= 0; if ($follow) { if (substr($top_item,0,1) eq '/') { $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_Win32) { $dir_pref = ($p_dir =~ m{^(?:\w:[/\\]?|[/\\])$} ? $p_dir : "$p_dir/" ); } elsif ($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= ( $p_dir eq '/' ? '/' : "$p_dir/" ); } local ($dir, $name, $prune, *DIR); 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. unless (opendir DIR, ($no_chdir ? $dir_name : $File::Find::current_dir)) { warnings::warnif "Can't opendir($dir_name): $!\n"; next; } @filenames = readdir DIR; closedir(DIR); @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 ($Is_Win32) { $dir_name = ($p_dir =~ m{^(?:\w:[/\\]?|[/\\])$} ? "$p_dir$dir_rel" : "$p_dir/$dir_rel"); $dir_pref = "$dir_name/"; } elsif ($^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 { $dir_name = ($p_dir eq '/' ? "/$dir_rel" : "$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 = ( $p_dir eq '/' ? '/' : "$p_dir/" ); $loc_pref = ( $dir_loc eq '/' ? '/' : "$dir_loc/" ); local ($dir, $name, $fullname, $prune, *DIR); unless ($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; # $File::Find::dir # Get the list of files in the current directory. unless (opendir DIR, ($no_chdir ? $dir_loc : $File::Find::current_dir)) { warnings::warnif "Can't opendir($dir_loc): $!\n"; next; } @filenames = readdir DIR; closedir(DIR); 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; $dir_name = ($p_dir eq '/' ? "/$dir_rel" : "$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__ =head1 NAME File::Find - Traverse a directory tree. =head1 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 }, '.'); =head1 DESCRIPTION These are functions for searching through directory trees doing work on each file found similar to the Unix I command. File::Find exports two functions, C and C. They work similarly but have subtle differences. =over 4 =item B find(\&wanted, @directories); find(\%options, @directories); C does a depth-first search over the given C<@directories> in the order they are given. For each file or directory found, it calls the C<&wanted> subroutine. (See below for details on how to use the C<&wanted> function). Additionally, for each directory found, it will C into that directory and continue the search, invoking the C<&wanted> function on each file or subdirectory in the directory. =item B finddepth(\&wanted, @directories); finddepth(\%options, @directories); C works just like C except that it invokes the C<&wanted> function for a directory I 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 where C works from the top of the tree down. =back Despite the name of the C function, both C and C perform a depth-first search of the directory hierarchy. =head2 %options The first argument to C is either a code reference to your C<&wanted> function, or a hash reference describing the operations to be performed for each file. The code reference is described in L below. Here are the possible keys for the hash: =over 4 =item C The value should be a code reference. This code reference is described in L below. The C<&wanted> subroutine is mandatory. =item C Reports the name of a directory only AFTER all its entries have been reported. Entry point C is a shortcut for specifying C<< { bydepth => 1 } >> in the first argument of C. =item C 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 C<$File::Find::dir>. Your preprocessing function is called after C, but before the loop that calls the C 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 I or I are in effect, C is a no-op. =item C 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 C<$File::Find::dir>. This hook is handy for summarizing a directory, such as calculating its disk usage. When I or I are in effect, C is a no-op. =item C Causes symbolic links to be followed. Since directory trees with symbolic links (followed) may contain files more than once and may even have cycles, a hash has to be built up with an entry for each file. This might be expensive both in space and time for a large directory tree. See L and L below. If either I or I is in effect: =over 4 =item * It is guaranteed that an I has been called before the user's C function is called. This enables fast file checks involving C<_>. Note that this guarantee no longer holds if I or I are not set. =item * There is a variable C<$File::Find::fullname> which 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 to C. =back This is a no-op on Win32. =item C This is similar to I 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 C function) is worse than just taking time, the option I should be used. This is also a no-op on Win32. =item C C, 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. C causes File::Find to die if any file is about to be processed a second time. C causes File::Find to ignore any duplicate files and directories but to proceed normally otherwise. =item C 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 C<"symbolic_link_name is a dangling symbolic link\n"> will be issued. If false, the dangling symbolic link will be silently ignored. =item C Does not C to each directory as it recurses. The C function will need to be aware of this, of course. In this case, C<$_> will be the same as C<$File::Find::name>. =item C If find is used in L (-T command line switch or if EUID != UID or if EGID != GID), then internally directory names have to be untainted before they can be C'd to. Therefore they are checked against a regular expression I. Note that all names passed to the user's C function are still tainted. If this option is used while not in taint-mode, C is a no-op. =item C See above. This should be set using the C quoting operator. The default is set to C. Note that the parentheses are vital. =item C If set, a directory which fails the I is skipped, including all its sub-directories. The default is to C in such a case. =back =head2 The wanted function The C function does whatever verifications you want on each file and directory. Note that despite its name, the C function is a generic callback function, and does B 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. =over 4 =item C<$File::Find::dir> is the current directory name, =item C<$_> is the current filename within that directory =item C<$File::Find::name> is the complete pathname to the file. =back 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 F you will have: $File::Find::dir = /some/path/ $_ = foo.ext $File::Find::name = /some/path/foo.ext You are chdir()'d to C<$File::Find::dir> when the function is called, unless C was specified. Note that when changing to directories is in effect, the root directory (F) is a somewhat special case inasmuch as the concatenation of C<$File::Find::dir>, C<'/'> and C<$_> is not literally equal to C<$File::Find::name>. The table below summarizes all variants: $File::Find::name $File::Find::dir $_ default / / . no_chdir=>0 /etc / etc /etc/x /etc x no_chdir=>1 / / / /etc / /etc /etc/x /etc /etc/x When C or C are in effect, there is also a C<$File::Find::fullname>. The function may set C<$File::Find::prune> to prune the tree unless C was specified. Unless C or C is specified, for compatibility reasons (find.pl, find2perl) there are in addition the following globals available: C<$File::Find::topdir>, C<$File::Find::topdev>, C<$File::Find::topino>, C<$File::Find::topmode> and C<$File::Find::topnlink>. This library is useful for the C tool (distributed as part of the App-find2perl CPAN distribution), which when fed, find2perl / -name .nfs\* -mtime +7 \ -exec rm -f {} \; -o -fstype nfs -prune produces 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 C<_> in the above C: the C<_> is a magical filehandle that caches the information from the preceding C, C, 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 C function. find(\&wanted, "./foo", "./bar", "./baz/epsilon"); In the example above, no file in F<./baz/> other than F<./baz/epsilon> will be evaluated by C. See also the script C on CPAN for a nice application of this module. =head1 WARNINGS If you run your program with the C<-w> switch, or if you use the C 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 L for more info about lexical warnings. =head1 BUGS AND CAVEATS =over 4 =item $dont_use_nlink You can set the variable C<$File::Find::dont_use_nlink> to 0 if you are sure the filesystem you are scanning reflects the number of subdirectories in the parent directory's C count. If you do set C<$File::Find::dont_use_nlink> to 0, you may notice an improvement in speed at the risk of not recursing into subdirectories if a filesystem doesn't populate C as expected. C<$File::Find::dont_use_nlink> now defaults to 1 on all platforms. =item 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 C is 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. =back =head1 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. =head1 SEE ALSO L, find2perl. =cut