test: print --help from the header comment block

The sed line range broke silently whenever the header grew or
shrank. Print from line 2 down to the first non-comment line
instead, so the usage text tracks the header.

1 files changed, 3 insertions, 1 deletions

diff --git a/test b/test
index 7ccfc8f..242cee3 100755
--- a/test
+++ b/test
@@ -24,7 +24,9 @@ cmd="${1:-unit}"
 case "$cmd" in
     unit|e2e|all|record|apk) ;;
     -h|--help)
-        sed -n '2,14p' "$0" >&2
+        # Usage is the header comment block: print from line 2 down to
+        # the first non-comment line.
+        awk 'NR > 1 && /^#/ { sub(/^# ?/, ""); print; next } NR > 1 { exit }' "$0" >&2
         exit 0 ;;
     *)
         echo "usage: $0 [unit|e2e|all|record|apk]" >&2