add defensive logic for lib mode

Author: oldratlee

console-text-color-themes.sh

@@ -2,6 +2,9 @@
 # @Function
 # show all console text color themes.
 
+readonly _ctct_PROG="$(basename "$(readlink -f "$0")")"
+[ "$_ctct_PROG" == 'console-text-color-themes.sh'  ] && readonly _ctct_is_direct_run=true
+
 colorEcho() {
     local combination="$1"
     shift 1
@@ -22,32 +25,36 @@ colorEchoWithoutNewLine() {
     } || echo -n "$@"
 }
 
-for style in 0 1 2 3 4 5 6 7; do
-    for fg in 30 31 32 33 34 35 36 37; do
-        for bg in 40 41 42 43 44 45 46 47; do
-            combination="${style};${fg};${bg}"
-            colorEchoWithoutNewLine "$combination" "$combination"
-            echo -n " "
+# if not directly run this script(use as lib), just export 2 helper functions,
+# and do NOT print anything.
+[ "$_ctct_is_direct_run" == "true" ] && {
+    for style in 0 1 2 3 4 5 6 7; do
+        for fg in 30 31 32 33 34 35 36 37; do
+            for bg in 40 41 42 43 44 45 46 47; do
+                combination="${style};${fg};${bg}"
+                colorEchoWithoutNewLine "$combination" "$combination"
+                echo -n " "
+            done
+            echo
         done
         echo
     done
-    echo
-done
 
-echo "Code sample to print color text:"
-echo -n '    echo -e "\033['
-colorEchoWithoutNewLine "3;35;40" "1;36;41"
-echo -n "m"
-colorEchoWithoutNewLine "0;32;40" "Sample Text"
-echo "\033[0m\""
-echo "Output of above code:"
-echo -e "    \033[1;36;41mSample Text\033[0m"
-echo
-echo "If you are going crazy to write text in escapes string like me,"
-echo "you can use colorEcho and colorEchoWithoutNewLine function in this script."
-echo
-echo "Code sample to print color text:"
-echo '    colorEcho "1;36;41" "Sample Text"'
-echo "Output of above code:"
-echo -n "    "
-colorEcho "1;36;41" "Sample Text"
+    echo "Code sample to print color text:"
+    echo -n '    echo -e "\033['
+    colorEchoWithoutNewLine "3;35;40" "1;36;41"
+    echo -n "m"
+    colorEchoWithoutNewLine "0;32;40" "Sample Text"
+    echo "\033[0m\""
+    echo "Output of above code:"
+    echo -e "    \033[1;36;41mSample Text\033[0m"
+    echo
+    echo "If you are going crazy to write text in escapes string like me,"
+    echo "you can use colorEcho and colorEchoWithoutNewLine function in this script."
+    echo
+    echo "Code sample to print color text:"
+    echo '    colorEcho "1;36;41" "Sample Text"'
+    echo "Output of above code:"
+    echo -n "    "
+    colorEcho "1;36;41" "Sample Text"
+}