package CuTmpdir;

# create, then chdir into a temporary sub-directory

# Copyright (C) 2007-2015, 2017 Free Software Foundation, Inc.

# This program is free software: you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation, either version 3 of the License, or

# (at your option) any later version.

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

use strict;

use warnings;

use File::Temp;

use File::Find;

our $ME = $0 || "";

my $dir;

sub skip_test($)

{

  warn "$ME: skipping test: unsafe working directory name: '$_[0]'\n";

  exit 77;

}

sub chmod_1

{

  my $name = $_;

  # Skip symlinks and non-directories.

  -l $name || !-d _

    and return;

  chmod 0700, $name;

}

sub chmod_tree

{

  # When tempdir fails, it croaks, which leaves $dir undefined.

  defined $dir

    or return;

  # Perform the equivalent of find "$dir" -type d -print0|xargs -0 chmod -R 700.

  my $options = {untaint => 1, wanted => \&chmod_1};

  find ($options, $dir);

}

sub import {

  my $prefix = $_[1];

  $ME eq '-' && defined $prefix

    and $ME = $prefix;

  if ($prefix !~ /^\//)

    {

      eval 'use Cwd';

      my $cwd = $@ ? '.' : Cwd::getcwd();

      $prefix = "$cwd/$prefix";

    }

  # Untaint for the upcoming mkdir.

  $prefix =~ m!^([-+\@\w./]+)$!

    or skip_test $prefix;

  $prefix = $1;

  my $original_pid = $$;

  my $on_sig_remove_tmpdir = sub {

    my ($sig) = @_;

    if ($$ == $original_pid and defined $dir)

      {

        chmod_tree;

        # Older versions of File::Temp lack this method.

        exists &File::Temp::cleanup

          and &File::Temp::cleanup;

      }

    $SIG{$sig} = 'DEFAULT';

    kill $sig, $$;

  };

  foreach my $sig (qw (INT TERM HUP))

    {

      $SIG{$sig} = $on_sig_remove_tmpdir;

    }

  $dir = File::Temp::tempdir("$prefix.tmp-XXXX", CLEANUP => 1 );

  chdir $dir

    or warn "$ME: failed to chdir to $dir: $!\n";

}

END {

  # Move cwd out of the directory we're about to remove.

  # This is required on some systems, and by some versions of File::Temp.

  chdir '..'

    or warn "$ME: failed to chdir to .. from $dir: $!\n";

  my $saved_errno = $?;

  chmod_tree;

  $? = $saved_errno;

}

1;