# capital letters by convention).
test_set_prereq () {
- satisfied="$satisfied$1 "
+ satisfied_prereq="$satisfied_prereq$1 "
+}
+satisfied_prereq=" "
+lazily_testable_prereq= lazily_tested_prereq=
+
+# Usage: test_lazy_prereq PREREQ 'script'
+test_lazy_prereq () {
+ lazily_testable_prereq="$lazily_testable_prereq$1 "
+ eval test_prereq_lazily_$1=\$2
+}
+
+test_run_lazy_prereq_ () {
+ script='
+mkdir -p "$TRASH_DIRECTORY/prereq-test-dir" &&
+(
+ cd "$TRASH_DIRECTORY/prereq-test-dir" &&'"$2"'
+)'
+ say >&3 "checking prerequisite: $1"
+ say >&3 "$script"
+ test_eval_ "$script"
+ eval_ret=$?
+ rm -rf "$TRASH_DIRECTORY/prereq-test-dir"
+ if test "$eval_ret" = 0; then
+ say >&3 "prerequisite $1 ok"
+ else
+ say >&3 "prerequisite $1 not satisfied"
+ fi
+ return $eval_ret
}
-satisfied=" "
test_have_prereq () {
# prerequisites can be concatenated with ','
for prerequisite
do
+ case " $lazily_tested_prereq " in
+ *" $prerequisite "*)
+ ;;
+ *)
+ case " $lazily_testable_prereq " in
+ *" $prerequisite "*)
+ eval "script=\$test_prereq_lazily_$prerequisite" &&
+ if test_run_lazy_prereq_ "$prerequisite" "$script"
+ then
+ test_set_prereq $prerequisite
+ fi
+ lazily_tested_prereq="$lazily_tested_prereq$prerequisite "
+ esac
+ ;;
+ esac
+
total_prereq=$(($total_prereq + 1))
- case $satisfied in
+ case "$satisfied_prereq" in
*" $prerequisite "*)
ok_prereq=$(($ok_prereq + 1))
;;