aux/lib.sh: Add mkstemp and mkdtemp, and copy uuid over

The tests were relying on the unspecified and non-standartized
behaviour of "mktemp".  Now they use "mkstemp()", a shim sh function to
provide the expected behaviour, and an accompanying "mkdtemp()"
function is also defined.

To further decouple from specific implementations and OS-behaviours and
quirks, a aux/lib.sh file containing both those functions was added.
Its purpose is to also allow code under aux/ to not depend on specific
behaviour.

"mkdtemp()" had to be replicated in aux/ci/ci-build.sh, since it runs
outside the repository.

1 files changed, 30 insertions, 0 deletions

diff --git a/aux/lib.sh b/aux/lib.sh
new file mode 100755
index 0000000..c31c4fb
--- /dev/null
+++ b/aux/lib.sh
@@ -0,0 +1,30 @@
+#!/bin/sh
+
+#
+# Generally, utilities that I expected to exist in POSIX, but don't.
+#
+
+uuid() {
+	# Taken from:
+	# https://serverfault.com/a/799198
+	od -xN20 /dev/urandom | \
+		head -1 | \
+		awk '{OFS="-"; print $2$3,$4,$5,$6,$7$8$9}'
+}
+
+tmpname() {
+	echo 'mkstemp(template)' | m4 -D template="${TMPDIR:-/tmp}/m4-tmpname."
+}
+
+mkstemp() {
+	name="$(tmpname)"
+	touch "$name"
+	echo "$name"
+}
+
+mkdtemp() {
+	name="$(tmpname)"
+	rm -f "$name"
+	mkdir "$name"
+	echo "$name"
+}