configure: generic run command

configure

@@ -19,6 +19,11 @@ err() {
     exit 1
 }
 
+run() {
+    msg "$@"
+    "$@"
+}
+
 need_ok() {
     if [ $? -ne 0 ]
     then
@@ -36,8 +41,7 @@ need_cmd() {
 make_dir() {
     if [ ! -d $1 ]
     then
-        msg "mkdir -p $1"
-        mkdir -p $1
+        run mkdir -p $1
     fi
 }
 
@@ -46,8 +50,7 @@ copy_if_changed() {
     then
         msg "leaving $2 unchanged"
     else
-        msg "cp $1 $2"
-        cp -f $1 $2
+        run cp -f $1 $2
         chmod u-w $2 # make copied artifact read-only
     fi
 }
@@ -57,8 +60,7 @@ move_if_changed() {
     then
         msg "leaving $2 unchanged"
     else
-        msg "mv $1 $2"
-        mv -f $1 $2
+        run mv -f $1 $2
         chmod u-w $2 # make moved artifact read-only
     fi
 }