Separating Filename Components

Use the following technique in tcsh scripts to extract components of a full pathname from a variable or parameter.

The full pathname:
% set fn="/Users/saruman/Documents/Essentials/todo.rtf" 
% echo $fn
/Users/saruman/Documents/Essentials/todo.rtf

Extract the pathname (head):
% echo $fn:h
/Users/saruman/Documents/Essentials

Extract the filename (tail):
% echo $fn:t
todo.rtf

Extract the extension:
% echo $fn:e
rtf

Remove the extension:
% echo $fn:r
/Users/saruman/Documents/Essentials/todo

To extract just the filename without the extension combine t and r:
% echo $fn
/Users/saruman/Documents/Essentials/todo.rtf

% echo $fn:t:r
todo

You can change a filename using substitution:
% echo $fn
/Users/saruman/Documents/Essentials/todo.rtf

% echo $fn:t:s/.rtf/.txt/
todo.txt