cmd/ln
ln is the Linux command for creating a link to a file or folder.
This page so far only discusses symbolic links, not hard links. (TODO)
General Syntax
ln [-r] --symbolic <filespec of existing file/folder> <filespec for new link>
scenarios
- If you're in the folder where you want the link to be created:
ln [-r] --symbolic <path to existing file/folder> ./<name for new link>
- If you're in the folder where the existing/real file is:
ln [-r] --symbolic ./<name of existing file> <path to new link>
notes
- A link cannot have the same name as a folder in the same directory (same rule as if it were a regular file).
- The
-roption just tellslnto calculate the relative path from the link to the existing file, and use that as the link URL; see "Relative Links" below.
Errors
- The error message "ln: failed to create symbolic link '<filename>': File exists" can be maddeningly misleading. It seems to always report the existing file, even when the problem is actually that the second filename (the link-name) already exists. Translation:
- "'<arg 1>': File exists" (arg 1 should be <existing file>): The link-name is the same as an existing file, possibly a folder.
- The fact that
lnreports the first param instead of the second one seems to be a bug. Yes, the first param is a file that does exist, but that's not the problem.
- The fact that
- "'<arg 2>': File exists" (arg 2 should be <name for link>): You've got the arguments backwards, and are trying to create a link under the same name as the existing file (to a file which doesn't exist).
- "'<arg 1>': File exists" (arg 1 should be <existing file>): The link-name is the same as an existing file, possibly a folder.
Relative Links
Note that when ln creates a relative link using the -r option, all it is doing is calculating the relative path for you and then using that as the link's target-string (URL). You can create a relative link without -r by just specifying a relative path. There's no difference between an absolute link and a relative link except whether the URL uses any relative-path syntax (e.g. "../", or no initial "/").
Relative links will still work even if the folder containing both files (the original and the link) is moved or copied, which can be useful for making links within a portable code repository. (Git does store link-files by default.)