1 files changed, 58 insertions, 0 deletions
diff --git a/bin/version-string.sh b/bin/version-string.sh
new file mode 100755
index 0000000..c1c5155
--- /dev/null
+++ b/bin/version-string.sh
@@ -0,0 +1,58 @@
+#!/usr/bin/env bash
+# Print a version string for the currently-checked-out code.
+# Copyright (C) 2023 Selene ToyKeeper
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+# Usage: version-string.sh [c|git|both]
+# Prints in C or Git format.  Defaults to both.
+
+function main {
+    # eat first arg if invoked via 'make'
+    [[ "version" = "$1" ]] && shift
+
+    # default to showing both formats
+    ARGS="$*"
+    [[ -z "$ARGS" ]] && ARGS="both"
+
+    for arg in $ARGS ; do
+        case "$arg" in
+            git|g)
+                git-describe
+                ;;
+            c|C)
+                c-version-string
+                ;;
+            *)
+                echo -n 'C:	' ; c-version-string
+                echo -n 'git:	' ; git-describe
+                ;;
+        esac
+    done
+}
+
+function git-describe {
+    git describe --tags --dirty --match='r2*'
+}
+
+function c-version-string {
+    # version = git tag + revs since + dirty flag
+    REV=$(git-describe)
+    # convert "r2020-01-01-158-g0abcdef-dirty" to "2020-01-01+158#1"
+    REV=$(echo "$REV" |
+        sed -E 's/^r//;
+                s/-dirty/#1/;
+                s/-g[0-9a-f]+//;
+                s/^([0-9]{4}-[0-9]{2}-[0-9]{2})-/\1+/;
+                '
+        )
+    # handle an empty name (can happen during github action runs)
+    if [[ -z "$REV" ]]; then
+        HASH=$(git describe --always)
+        REV="0.$HASH"
+    fi
+    # print the version string
+    echo "$REV"
+}
+
+main "$@"
+