#! /bin/sh

# Use df 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.

: ${CANDIDATE_TMP_DIRS=not_set}

# Work around a bug in the way Ultrix4.3a's /bin/sh handles multi-word
# variables set with ${VAR="VALUE"}
test "$CANDIDATE_TMP_DIRS" = not_set \
  && CANDIDATE_TMP_DIRS="$TMPDIR /tmp /var/tmp /usr/tmp $HOME"

other_partition_tmpdir=

# WARNING: using sed like this to extract the mount point will fail
# if the mount point name contains `% '.
dot_mount_point=`df --no-sync -P . | sed -n '2s/.*%  *//p'`
for d in $CANDIDATE_TMP_DIRS; do

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

  d_mount_point=`df --no-sync -P $d | sed -n '2s/.*%  *//p'`

  # 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/df-$$" > /dev/null 2>&1; then
    other_partition_tmpdir="$d/df-$$"
    break
  fi

done

if test -z "$other_partition_tmpdir"; then
  cat <<EOF 1>&2
**************************************
This test 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.
**************************************
EOF
    #'
fi

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