23.7 File Name Aliases

Symbolic links and hard links both make it possible for several file names to refer to the same file. Hard links are alternate names that refer directly to the file; all the names are equally valid, and no one of them is preferred. By contrast, a symbolic link is a kind of defined alias: when ‘foo’ is a symbolic link to ‘bar’, you can use either name to refer to the file, but ‘bar’ is the real name, while ‘foo’ is just an alias. More complex cases occur when symbolic links point to directories.

Normally, if you visit a file which Emacs is already visiting under a different name, Emacs displays a message in the echo area and uses the existing buffer visiting that file. This can happen on systems that support hard or symbolic links, or if you use a long file name on a system that truncates long file names, or on a case-insensitive file system. You can suppress the message by setting the variable find-file-suppress-same-file-warnings to a non-nil value. You can disable this feature entirely by setting the variable find-file-existing-other-name to nil: then if you visit the same file under two different names, you get a separate buffer for each file name.

If the variable find-file-visit-truename is non-nil, then the file name recorded for a buffer is the file's truename (made by replacing all symbolic links with their target names), rather than the name you specify. Setting find-file-visit-truename also implies the effect of find-file-existing-other-name.