2.2.1 Symbolic Links

Symbolic links are names that reference other files. GNU find will handle symbolic links in one of two ways; firstly, it can dereference the links for you - this means that if it comes across a symbolic link, it examines the file that the link points to, in order to see if it matches the criteria you have specified. Secondly, it can check the link itself in case you might be looking for the actual link. If the file that the symbolic link points to is also within the directory hierarchy you are searching with the find command, you may not see a great deal of difference between these two alternatives.

By default, find examines symbolic links themselves when it finds them (and, if it later comes across the linked-to file, it will examine that, too). If you would prefer find to dereference the links and examine the file that each link points to, specify the ‘-L’ option to find. You can explicitly specify the default behaviour by using the ‘-P’ option. The ‘-H’ option is a half-way-between option which ensures that any symbolic links listed on the command line are dereferenced, but other symbolic links are not.

Symbolic links are different from “hard links” in the sense that you need permission to search the directories in the linked-to file name to dereference the link. This can mean that even if you specify the ‘-L’ option, find may not be able to determine the properties of the file that the link points to (because you don't have sufficient permission). In this situation, find uses the properties of the link itself. This also occurs if a symbolic link exists but points to a file that is missing.

The options controlling the behaviour of find with respect to links are as follows :-

‘-P’

find does not dereference symbolic links at all. This is the default behaviour. This option must be specified before any of the file names on the command line.

‘-H’

find does not dereference symbolic links (except in the case of file names on the command line, which are dereferenced). If a symbolic link cannot be dereferenced, the information for the symbolic link itself is used. This option must be specified before any of the file names on the command line.

‘-L’

find dereferences symbolic links where possible, and where this is not possible it uses the properties of the symbolic link itself. This option must be specified before any of the file names on the command line. Use of this option also implies the same behaviour as the ‘-noleaf’ option. If you later use the ‘-H’ or ‘-P’ options, this does not turn off ‘-noleaf’.

‘-follow’

This option forms part of the “expression” and must be specified after the file names, but it is otherwise equivalent to ‘-L’. The ‘-follow’ option affects only those tests which appear after it on the command line. This option is deprecated. Where possible, you should use ‘-L’ instead.

The following differences in behavior occur when the ‘-L’ option is used:

• find follows symbolic links to directories when searching directory trees.
• ‘-lname’ and ‘-ilname’ always return false (unless they happen to match broken symbolic links).
• ‘-type’ reports the types of the files that symbolic links point to. This means that in combination with ‘-L’, ‘-type l’ will be true only for broken symbolic links. To check for symbolic links when ‘-L’ has been specified, use ‘-xtype l’.
• Implies ‘-noleaf’ (see Directories).

If the ‘-L’ option or the ‘-H’ option is used, the file names used as arguments to ‘-newer’, ‘-anewer’, and ‘-cnewer’ are dereferenced and the timestamp from the pointed-to file is used instead (if possible – otherwise the timestamp from the symbolic link is used).