How do I save the current buffer to a different filename and continue editing under the new name?

Explanation

:saveas saves the buffer to a new file and redirects all future :w commands to write to that new filename — making it the true "Save As" command in Vim. This is different from :w newname (which writes a copy but keeps the original as the buffer's file) or :file newname (which renames the buffer without saving).

How it works

• :saveas newfile.txt — write current buffer to newfile.txt and set it as the new filename
• After :saveas, pressing :w writes to the new filename, not the original
• The original file is not modified or deleted
• If the new filename already exists, Vim raises an error (use :saveas! newname to overwrite)

Example

You have draft.md open. You want to save it as final.md and keep editing under that name:

:saveas final.md

Now the buffer is associated with final.md. Any subsequent :w writes to final.md. The original draft.md remains unchanged.

Tips

• Compare with :w newname — this writes a copy but the buffer stays tied to the original file
• Compare with :file newname — this renames the buffer in memory but does not save to disk
• Use :saveas! to overwrite an existing file without confirmation
• After :saveas, run :!rm old-file.txt from within Vim to clean up the original if needed