Add existing scripts

command_exists.sh

@@ -0,0 +1,23 @@
+# To have scripts not write everything out to stdout so results can be captured
+# redirect any output not wanted to /dev/null
+#
+# This is the original that outputs 1 or 0 with echo
+command_exists_1 () {
+    if type "$1" >> /dev/null; then
+        echo "1"
+    else
+        echo "0"
+    fi
+}
+
+# A better version is to use the return keyword
+# This command can be used in an if statement, if needed
+# The logic has to be reversed - the shell treats 0 as success
+command_exists() {
+    if type "$1" >> /dev/null; then
+        return 0
+    else
+        return 1
+    fi
+}
+