tmp-dir

PROGRAM="${0##*/}"
TMPDIR_TEMPLATE="$PROGRAM.XXXXXXXXXXXXX"
TMPFILE_TEMPLATE="XXXXXX"

# note: printf is used instead of echo to avoid backslash
# processing and to properly handle values that begin with a '-'.

log() { printf '%s\n' "$*"; }
error() { log "ERROR: $*" >&2; }
fatal() { error "$@"; exit 1; }

# appends a command to a trap
#
# - 1st arg:  code to add
# - remaining args:  names of traps to modify
#
trap_add() {
    trap_add_cmd=$1; shift || fatal "${FUNCNAME} usage error"
    for trap_add_name in "$@"; do
        trap -- "$(
            # helper fn to get existing trap command from output
            # of trap -p
            extract_trap_cmd() { printf '%s\n' "$3"; }
            # print the new trap command
            printf '%s\n' "${trap_add_cmd}"
            # print existing trap command with newline
            eval "extract_trap_cmd $(trap -p "${trap_add_name}")"
        )" "${trap_add_name}" \
            || fatal "unable to add to trap ${trap_add_name}"
    done
}

# set the trace attribute for the above function.  this is
# required to modify DEBUG or RETURN traps because functions don't
# inherit them unless the trace attribute is set
declare -f -t trap_add

_maketmpdir() {
    local tmpdirpath=${2:-${TMPDIR:-/tmp}}
    eval $1="$(mktemp -d "${tmpdirpath}/${TMPDIR_TEMPLATE}")"
    TRAP_NAME="rm_tmpdir${RANDOM}"
    eval "${TRAP_NAME}() { rm -rf "${!1}"; }"
    trap_add "${TRAP_NAME}" EXIT
}

maketmpdir() {
    local tmpdir=${1:-LOCAL_TMPDIR}
    if [[ -n "${!tmpdir}" && -d "${!tmpdir}" ]]
    then
        return
    fi
    _maketmpdir "${tmpdir}"
}

if [[ $(uname) == Darwin ]]; then
    _makesecuretmpdir() {
        _maketmpdir "$1"
        DARWIN_RAMDISK_DEV="$(hdid -drivekey system-image=yes -nomount 'ram://32768' | cut -d ' ' -f 1)" # 32768 sectors = 16 mb
        [[ -z "${DARWIN_RAMDISK_DEV}" ]] && { echo "Error: could not create ramdisk." 1>&2; exit 1; }
        newfs_hfs -M 700 "${DARWIN_RAMDISK_DEV}" &>/dev/null || { echo "Error: could not create filesystem on ramdisk." 1>&2 ; exit 1; }
        mount -t hfs -o noatime -o nobrowse "${DARWIN_RAMDISK_DEV}" "${!1}" || { echo "Error: could not mount filesystem on ramdisk." 1>&2 ; exit 1; }
        TRAP_NAME="unmount_tmpdir${RANDOM}"
        eval "${TRAP_NAME}() { [[ -n "${!1}" && -d "${!1}" && -n "${DARWIN_RAMDISK_DEV}" ]] || return; umount "${!1}"; diskutil quiet eject "${DARWIN_RAMDISK_DEV}"; }"
        trap_add "${TRAP_NAME}" EXIT
    }
else
    _makesecuretmpdir() {
    	if [[ -d /dev/shm && -w /dev/shm && -x /dev/shm ]]; then
    	    _maketmpdir "$1" /dev/shm
    	else
            _maketmpdir "$1"
    	fi
    }
fi

makesecuretmpdir() {
    local tmpdir=${1:-LOCAL_SECURE_TMPDIR}
    if [[ -n "${!tmpdir}" && -d "${!tmpdir}" ]]
    then
        return
    fi
    _makesecuretmpdir "${tmpdir}"
}

_gettmpfilename() {
    eval $1="$(mktemp -u "${!2}/${TMPFILE_TEMPLATE}")"
}

gettmpfilename() {
    maketmpdir
    _gettmpfilename "${1:-LOCAL_TMPFILE}" LOCAL_TMPDIR
}

getsecuretmpfilename() {
    makesecuretmpdir
    _gettmpfilename "${1:-LOCAL_SECURE_TMPFILE}" LOCAL_SECURE_TMPDIR
}