Create getopts.md

Author: pasvorn

getopts.md

@@ -0,0 +1,26 @@
+An example of how to use ```getopts``` shell built-in command to process shell arguments. 
+The use of ```getopts``` is actually well-known with old-timers. 
+However, new gens are usually cycled to ```agrc``` and ```argv```. 
+Save some time and use the built-in. :)
+
+```bash
+ while getopts df: flag
+    do
+        case $flag in
+
+            d)
+                  echo debugging on
+                  ;;
+            f)
+                 file=$OPTARG
+                 echo filename is $file
+                 ;;
+            ?)
+                exit
+                ;;
+        esac
+   done
+shift $(( OPTIND - 1 ))  # shift past the last flag or argument
+
+echo parameters are $*
+```