#!/bin/sh

# Use stat to find a writable directory on a file system different from that
# of the current directory.  If one is found, create a temporary directory
# inside it.

# Copyright (C) 1998-2020 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 <https://www.gnu.org/licenses/>.

test "${CANDIDATE_TMP_DIRS+set}" = set \
  || CANDIDATE_TMP_DIRS="$TMPDIR /tmp /dev/shm /var/tmp /usr/tmp $HOME"

other_partition_tmpdir=

dot_mount_point=$(stat -c %d .)
for d in $CANDIDATE_TMP_DIRS; do

  # Skip nonexistent directories.
  test -d "$d" || continue

  d_mount_point=$(stat -L -c %d "$d")

  # Same partition?  Skip it.
  test "x$d_mount_point" = "x$dot_mount_point" && continue

  # See if we can create a directory in it.
  if mkdir "$d/tmp$$" > /dev/null 2>&1; then
    other_partition_tmpdir="$d/tmp$$"
    break
  fi

done

if test -z "$other_partition_tmpdir"; then
  skip_ \
"requires a writable directory on a different disk partition,
and I couldn't find one.  I tried these:
  $CANDIDATE_TMP_DIRS
Set your environment variable CANDIDATE_TMP_DIRS to make
this test use a different list."
fi

test "$VERBOSE" = yes && set -x