AWK = "/usr/bin/original-awk"
    awk_switches = " -f"
    trivial_program = " 'BEGIN { print \"hi\" }' "
    no_output = " >/dev/null 2>/dev/null"
    if (0 != system(awk_executable trivial_program no_output)) {
        AWK = "/usr/bin/awk"
        # now, what do we need to hand it to get no bells and
        # whistles? with GNU awk, we need -c, but One True Awk does
        # not recognize this switch, and will exit with an error when
        # it is provided.
        if(0 == system(AWK " -c " trivial_program no_output)) {
            awk_switches = " -cf"
        } else {
            # leave awk_switches alone
        }

    if(!BUILD_AWK) {
        print "tmpl.awk: you must set BUILD_AWK and TARGET_AWK variables" >"/dev/stderr"
        exit 1

    BAWK = BUILD_AWK " -v BUILD_AWK=\"" BUILD_AWK "\" -v TARGET_AWK=\"" TARGET_AWK "\" "

    print "#!" AWK awk_switches

    print "#!" TARGET_AWK " -f"

    while((AWK " -f tmpl.awk " fn | getline) > 0)

    # setting a variable to the command whose output is to be read,
    # then using the variable, sets mawk at ease; not doing so seems
    # to put it in an infinite loop. i have not diagnosed this.
    command = BAWK " -f tmpl.awk " fn
    while((command | getline) > 0)

    while((AWK " -f tmpl.awk " fn | getline) > 0)

    command = BAWK " -f tmpl.awk " fn
    while((command | getline) > 0)

    if(!AWK)
        AWK = "awk"

    if(!BUILD_AWK) {
        print "tmpl-depends.awk: you must set the BUILD_AWK variable" >"/dev/stderr"
        exit 1
    }
    BAWK = BUILD_AWK " -v BUILD_AWK=\"" BUILD_AWK "\" "

    if(fn != "image.awk")
        while((AWK " -f tmpl-depends.awk -v TARGET=\"" TARGET "\" " fn | getline) > 0)

    if(fn != "image.awk") {
        command = BAWK " -f tmpl-depends.awk -v TARGET=\"" TARGET "\" " fn
        while((command | getline) > 0)

    }

  echo "$@" | original-awk -v PROMPT= -v LOG_LEVEL=$LOG_LEVEL -f glotawk

    echo "$@" | ${TEST_AWK:-original-awk} -v PROMPT= -v LOG_LEVEL=$LOG_LEVEL -f glotawk

AWK = original-awk

AWK = gawk -c
#AWK = original-awk
# used to build the single glotawk file.
BUILD_AWK  ?= $(AWK)
# used to run the tests using the built glotawk.
TEST_AWK   ?= $(AWK)
# not run. written in the shebang at the top of the built glotawk.
TARGET_AWK ?= $(AWK)

\n\
Variables:\n\
        AWK            the awk used if none of the below are given\n\
        BUILD_AWK      the awk used to build glotawk\n\
        TEST_AWK       the awk used to test the built glotawk\n\
        TARGET_AWK     the awk written in the shebang at the top of glotawk\n\

	awk -f tmpl-depends.awk *.tmpl.awk > .depend

	$(BUILD_AWK) -v BUILD_AWK="$(BUILD_AWK)" -f tmpl-depends.awk *.tmpl.awk > .depend

	$(AWK) -f tmpl.awk glotawk-build.tmpl.awk > $@

	$(BUILD_AWK) -v BUILD_AWK="$(BUILD_AWK)" -v TARGET_AWK="$(TARGET_AWK)" -f tmpl.awk glotawk-build.tmpl.awk > $@

	(echo "(dump-dot \"before-gc.dot\")"; echo "(gc-dot \"marks.dot\" \"sweeps.dot\")"; echo "(dump \"$@\")"; echo "(dump-dot \"after-gc.dot\")") | $(AWK) -f glotawk-build.awk

	(echo "(dump-dot \"before-gc.dot\")"; echo "(gc-dot \"marks.dot\" \"sweeps.dot\")"; echo "(dump \"$@\")"; echo "(dump-dot \"after-gc.dot\")") | $(BUILD_AWK) -f glotawk-build.awk

	$(AWK) -f tmpl.awk glotawk-run.tmpl.awk > $@

	$(BUILD_AWK) -v BUILD_AWK="$(BUILD_AWK)" -v TARGET_AWK="$(TARGET_AWK)" -f tmpl.awk glotawk-run.tmpl.awk > $@

	./sane_lisp; x=$$?; if [ $$x -eq 0 ]; then echo --pass--; else echo --FAIL--; fi; return $$x

	TEST_AWK="$(TEST_AWK)" ./sane_lisp; x=$$?; if [ $$x -eq 0 ]; then echo --pass--; else echo --FAIL--; fi; return $$x

	bash -c "time for x in $(A_HUNDRED_THINGS); do ./glotawk benchmark.glotawk >/dev/null; echo -n .; done; echo"

	bash -c "time for x in $(A_HUNDRED_THINGS); do $(TEST_AWK) -f ./glotawk benchmark.glotawk >/dev/null; echo -n .; done; echo"

	bash -c "time for x in $(A_HUNDRED_THINGS); do echo 3 | ./glotawk >/dev/null; echo -n .; done; echo"

	bash -c "time for x in $(A_HUNDRED_THINGS); do echo 3 | $(TEST_AWK) -f ./glotawk >/dev/null; echo -n .; done; echo"

	echo "(gc-dot \"gc-marks.dot\" \"gc-sweeps.dot\")" | ./glotawk -v LOG_LEVEL=3

	echo "(gc-dot \"gc-marks.dot\" \"gc-sweeps.dot\")" | $(BUILD_AWK) -f ./glotawk -v LOG_LEVEL=3