Update runtests (shellcheck)

scripts/runtests.in

@@ -15,6 +15,8 @@ export LANGUAGES=
 
 TOPDIR="$(realpath "$(dirname "$0")/..")"
 
+# $prefix is used in the substitutions of @...@ strings below
+# shellcheck disable=SC2034
 prefix=@prefix@
 # Shellcheck does not know about substitutions
 # shellcheck disable=SC2050
@@ -176,22 +178,22 @@ run_tests () {
     find "$*" -name test.hal -or -name test.sh -or -name test \
 	| sort > "$TMPDIR/alltests"
 
-    while read testname; do
-	testdir=$(dirname $testname)
+    while read -r testname; do
+	testdir=$(dirname "$testname")
         # check if there's a "musthave" file with prerequisites from config.h
-        if [ -e $testdir/musthave ] ; then
+        if [ -e "$testdir/musthave" ] ; then
             # one prerequisite per line
             while IFS= read -r prereq ; do
                 if ! grep --quiet --regexp "^#define HAVE_$prereq.*" "$TOPDIR/src/config.h" ; then
                     echo "Skipping test for missing prerequisite \"$prereq\": $testdir" 1>&2
-                    SKIP=$(($SKIP+1))
+                    SKIP=$((SKIP + 1))
                     continue 3
                 fi
-            done < $testdir/musthave
+            done < "$testdir/musthave"
         fi
         # skip test if there's a "skip" file
-	if [ -e $testdir/skip ]; then
-	    if ! [ -x $testdir/skip ] || ! $testdir/skip; then
+	if [ -e "$testdir/skip" ]; then
+	    if ! [ -x "$testdir/skip" ] || ! "$testdir/skip"; then
 
 		echo "Skipping disabled test: $testdir" 1>&2
 		SKIP=$((SKIP + 1))

scripts/shellcheck.sh

@@ -5,37 +5,54 @@ if ! command -v shellcheck > /dev/null; then
     exit 1
 fi
 
-echo Shellcheck
-
 # This script is supposed to be in the scripts subdirectory
 TOPDIR=$(realpath --relative-to=. "$(dirname "$0")/..")
 
 # Exclude tracking includes and don't complain about include paths
 SHELLCHECK_OPTS="--exclude=SC1090,SC1091"
 export SHELLCHECK_OPTS
 
-#
-# With the file command we can find all scripts.
-#   Note: perform shellcheck with a distclean tree. Some scripts are
-#   generated by configure from .in files.
-#
-# Without the file command we just look for script file names.
-#
-if [ -n "$(command -v file)" ]; then
-    mapfile -t FILES < <(find "$TOPDIR" -type f \
-                 -not -path "*/.git/*" \
-                 -not -path "*/autom4te.cache/*" \
-                 -not -name "*~" \
-                 -not -path "*/tcl/*" \
-                 -not -name "*.tcl" \
-                 -not -name "configure" \
-                 -not -name "config.guess" \
-                 -not -name "config.status" \
-                 -not -name "config.sub" \
-                 -not -name "install-sh" \
-                 -exec file {} + | awk -F: '/shell script/{print $1}')
+# Check if files are specified on the command line. If so, only use those.
+if [ $# -gt 0 ]; then
+    case "$1" in
+    -h|--help*)
+        cat <<EOF
+Shellcheck script to check LinuxCNC shell scripts.
+Usage: shellcheck.sh [-h|--help] [files...]
+  -h, --help   This help message
+
+Specify one or more files on the command line if you only want those files
+to be checked. The script will search all of the LinuxCNC source tree for
+shell scripts if no files are specified on the command line.
+EOF
+        exit 1
+        ;;
+    esac
+    FILES=( "$@" )
 else
-    mapfile -r FILES < <(find "$TOPDIR" -type f -name "*.sh")
+    #
+    # With the file command we can find all scripts.
+    #   Note: perform shellcheck with a distclean tree. Some scripts are
+    #   generated by configure from .in files.
+    #
+    # Without the file command we just look for script file names.
+    #
+    if [ -n "$(command -v file)" ]; then
+        mapfile -t FILES < <(find "$TOPDIR" -type f \
+                     -not -path "*/.git/*" \
+                     -not -path "*/autom4te.cache/*" \
+                     -not -name "*~" \
+                     -not -path "*/tcl/*" \
+                     -not -name "*.tcl" \
+                     -not -name "configure" \
+                     -not -name "config.guess" \
+                     -not -name "config.status" \
+                     -not -name "config.sub" \
+                     -not -name "install-sh" \
+                     -exec file {} + | awk -F: '/shell script/{print $1}')
+    else
+        mapfile -r FILES < <(find "$TOPDIR" -type f -name "*.sh")
+    fi
 fi
 
 if [ "${#FILES[@]}" -gt 0 ]; then