How do I reference just the extension, stem, or directory of the current file in a Vim command?

Explanation

Vim exposes the current filename as % in Ex commands, and you can apply modifiers to extract specific parts of the path. These filename modifiers are indispensable when writing commands that need to work with related files — opening a test file for the current source file, compiling the current file, or switching between header and implementation files.

How it works

Modifiers are appended to % with a colon:

• % — full path as opened (e.g., src/utils/parser.py)
• %:p — absolute path (e.g., /home/user/project/src/utils/parser.py)
• %:h — head (directory only): src/utils
• %:t — tail (filename only): parser.py
• %:r — root (filename without extension): src/utils/parser
• %:e — extension only: py
• %:t:r — filename without extension and without directory: parser

Modifiers can be chained: %:p:h gives the absolute directory of the current file.

Example

Open the corresponding test file in a split:

:vsplit %:r_test.%:e

For src/parser.py, this opens src/parser_test.py. Compile the current C file:

:!gcc % -o %:r

Insert the current filename into the buffer while in insert mode:

<C-r>%

Tips

• Use expand('%:p:h') in Vimscript to get the absolute directory programmatically
• # refers to the alternate (previously edited) file and accepts the same modifiers: #:t
• In the command line, <C-r>% pastes the current filename at the cursor
• :lcd %:h changes the local working directory to the current file's directory