Fix some shellcheck linter warnings

* admin/diff-tar-files:
* admin/merge-gnulib:
* admin/merge-pkg-config:
* admin/update-copyright:
* build-aux/git-hooks/prepare-commit-msg:
* make-dist: Fix some shellcheck linter warnings.

4 files changed, 7 insertions, 7 deletions

diff --git a/admin/diff-tar-files b/admin/diff-tar-files
index cbcec862329..52c7a480a4c 100755
--- a/admin/diff-tar-files
+++ b/admin/diff-tar-files
@@ -35,7 +35,7 @@ old_tmp=/tmp/old.$$
 new_tmp=/tmp/new.$$
 trap "rm -f $old_tmp $new_tmp; exit 1" 1 2 15
 
-tar tzf $old_tar | sed -e 's,^[^/]*,,' | sort > $old_tmp
-tar tzf $new_tar | sed -e 's,^[^/]*,,' | sort > $new_tmp
+tar tzf "$old_tar" | sed -e 's,^[^/]*,,' | sort > $old_tmp
+tar tzf "$new_tar" | sed -e 's,^[^/]*,,' | sort > $new_tmp
 diff -u $old_tmp $new_tmp
 rm -f $new_tmp $old_tmp
diff --git a/admin/merge-gnulib b/admin/merge-gnulib
index 880dc5eef53..ed701ce1339 100755
--- a/admin/merge-gnulib
+++ b/admin/merge-gnulib
@@ -105,8 +105,8 @@ for module in $AVOIDED_MODULES; do
   avoided_flags="$avoided_flags --avoid=$module"
 done
 
-"$gnulib_srcdir"/gnulib-tool --dir="$src" $GNULIB_TOOL_FLAGS \
-	$avoided_flags $GNULIB_MODULES &&
+"$gnulib_srcdir"/gnulib-tool --dir="$src" "$GNULIB_TOOL_FLAGS" \
+        "$avoided_flags" "$GNULIB_MODULES" &&
 rm -- "$src"lib/gl_openssl.h "$src"m4/fcntl-o.m4 \
       "$src"m4/gl-openssl.m4 \
       "$src"m4/gnulib-cache.m4 "$src"m4/gnulib-tool.m4 \
diff --git a/admin/merge-pkg-config b/admin/merge-pkg-config
index 6ec54ce9edf..ab705ccebfa 100755
--- a/admin/merge-pkg-config
+++ b/admin/merge-pkg-config
@@ -60,4 +60,4 @@ test -d m4 || {
 
 printf >&2 '%s\n' "$0: copying $dir/pkg.m4 to m4/pkg.m4"
 
-cp $dir/pkg.m4 m4
+cp "$dir"/pkg.m4 m4
diff --git a/admin/update-copyright b/admin/update-copyright
index a70d7a3ff93..f392b09c10b 100755
--- a/admin/update-copyright
+++ b/admin/update-copyright
@@ -53,7 +53,7 @@ repo_files=$(git ls-files) &&
 # . They are GMP files, maintained by the GMP project, with their own dates.
 # . Their format cannot withstand changing the contents of copyright strings.
 
-updatable_files=$(find $repo_files \
+updatable_files=$(find "$repo_files" \
   ! -name COPYING \
   ! -name doclicense.texi \
   ! -name gpl.texi \
@@ -74,4 +74,4 @@ updatable_files=$(find $repo_files \
   ! -name 'mini-gmp.[ch]' \
   -print) &&
 
-build-aux/update-copyright $updatable_files
+build-aux/update-copyright "$updatable_files"