diff options
Diffstat (limited to 'lisp')
| -rw-r--r-- | lisp/files.el | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/lisp/files.el b/lisp/files.el index 12121872748..860b9ca7249 100644 --- a/lisp/files.el +++ b/lisp/files.el @@ -5033,14 +5033,16 @@ extension, the value is \"\"." ""))))) (defun file-name-with-extension (filename extension) - "Set the EXTENSION of a FILENAME. + "Return FILENAME modified to have the specified EXTENSION. The extension (in a file name) is the part that begins with the last \".\". +This function removes any existing extension from FILENAME, and then +appends EXTENSION to it. -Trims a leading dot from the EXTENSION so that either \"foo\" or -\".foo\" can be given. +EXTENSION may include the leading dot; if it doesn't, this function +will provide it. -Errors if the FILENAME or EXTENSION are empty, or if the given -FILENAME has the format of a directory. +It is an error if FILENAME or EXTENSION is empty, or if FILENAME +is in the form of a directory name according to `directory-name-p'. See also `file-name-sans-extension'." (let ((extn (string-trim-left extension "[.]"))) |