-%s: This utility requires a directory name on the command line.\n\
-The subdirectories under that directory will be shown. If a second paramter\n\
-is provided, it is taken as a pattern that will be used to show the files in\n\
-those directories also. Otherwise, just the tree of directories is shown.\n\
+%s: This utility shows the sub-directory structure for a chosen directory.\n\
+It expects a directory name to be provided on the command line. If no\n\
+directory is provided, then the current directory is assumed. The sub-\n\
+directories under the chosen directory will be displayed on the console in a\n\
+stylized textual tree. If a second parameter is provided, it is taken as a\n\
+file pattern that causes matching files to be displayed. Without a pattern,\n\
+just the directory tree is shown.\n\
+For example:\n\
+ dirtree\n\
+ => shows the directory structure of the current directory.\n\
+ dirtree udon\n\
+ => shows the structure of directory 'udon'\n\
+ dirtree soba \"*.txt\"\n\
+ => displays all text files and sub-directories of 'soba'\n\