maint/build ~ add dev helper scripts to derive available utils for feature set

util/show-utils.sh

@@ -0,0 +1,21 @@
+#!/bin/sh
+
+# spell-checker:ignore (utils) cksum dircolors hashsum mkdir mktemp printenv printf readlink realpath relpath rmdir shuf tsort unexpand uutils
+# spell-checker:ignore (jq) deps startswith
+
+# refs: <https://forge.rust-lang.org/release/platform-support.html> , <https://docs.rs/platforms/0.2.1/platforms/platform/tier1/index.html>
+
+# default ("Tier 1" cross-platform) utility list
+default_utils="base32 base64 basename cat cksum comm cp cut date dircolors dirname echo env expand expr factor false fmt fold hashsum head join link ln ls mkdir mktemp more mv nl od paste printenv printf ptx pwd readlink realpath relpath rm rmdir seq shred shuf sleep sort split sum tac tail tee test tr true truncate tsort unexpand uniq wc yes"
+
+# `jq` available?
+unset JQ
+jq --version 1>/dev/null 2>&1
+if [ $? -eq 0 ]; then export JQ="jq"; fi
+
+if [ -z "${JQ}" ]; then
+    echo 'WARN: missing `jq` (install with `sudo apt install jq`); falling back to default (only fully cross-platform) utility list' 1>&2
+    echo $default_utils
+else
+    cargo metadata $* --format-version 1 | jq -r "[.resolve.nodes[] | {id: .id, deps: [.deps[].name]}] | .[] | select(.id|startswith(\"uutils\")) | [.deps[] | select(startswith(\"uu_\"))] | [.[] | sub(\"^uu_\"; \"\")] | join(\" \")"
+fi