improve usearg

share/eterbuild/functions/common

@@ -468,13 +468,17 @@ showcmd()
 	SETCOLOR_NORMAL
 }
 
-# Example: $ command $(usearg -d "$PARAM")
-# will add -d "$PARAM" if $PARAM is not empty
+# Example:
+# $ command $(usearg -d "$PARAM")
+#  will add -d "$PARAM" if $PARAM is not empty
+# $ command $(usearg -d "$PARAM" "empty-word)
+# will add -d "$PARAM" if $PARAM is not 'empty-word'
 usearg()
 {
         local ARG=$1
         shift
-        [ -n "$1" ] && echo "$ARG $@"
+
+        [ "$1" != "$2" ] && echo "$ARG $1"
 }
 
 # return 0 if arg1 >= arg2

tests/test_usearg.sh

@@ -8,8 +8,10 @@ check()
 	[ "$2" != "$3" ] && echo "FATAL with '$1': result '$2' do not match with '$3'" || echo "OK for '$1' with '$2'"
 }
 
-echo "$(usearg -f TEST)"
-echo "$(usearg -f TEST MORE)"
-echo "$(usearg -f $TEST)"
+check "-f TEST" "$(usearg -f TEST)" "-f TEST"
+check "-f 'TEST MORE'" "$(usearg -f 'TEST MORE')" "-f TEST MORE"
+check "-f 'TEST MORE'" "$(usearg -f TEST MORE)" "-f TEST"
+check "-f 'TEST TEST'" "$(usearg -f TEST TEST)" ""
+check "TEST=$TEST-f \$TEST" "$(usearg -f $TEST)" ""
 TEST=124
-echo "$(usearg -f $TEST)"
+check "TEST=$TEST -f \$TEST" "$(usearg -f $TEST)" "-f 124"