Changes between Version 9 and Version 10 of DiffFromUnix

Timestamp:

2013-03-28T13:27:45Z (12 years ago)

Author:

Jakub Jermář

Comment:

—

DiffFromUnix

@@ -21 +21 @@
 When the HelenOS file system layer sees a reference to '.' (current directory) or '..' (parent directory) in a file system path, it does not resolve it by traversing through the corresponding special directory entries, but rather makes use of its knowledge of the used absolute paths. Upon accepting the path from the user, HelenOS resolves references to '.' and '..' lexically by leaving out all occurrences of '.' and 'component/..' from the path. This represents a simplification of individual file system servers and allows file systems that do not explicitly understand the notion of the current and the parent directory in their directory entries to be supported.
 
-Lexical dot-dot resolution removes the potential for an ambiguous behavior when the child directory is entered using alternate paths (eg. via a symlink) and the user then goes back to the parent directory using dot-dot. This problem is inherent to UNIX-like systems and, if not dealt with by the shell, the following scenario is possible:
+Lexical dot-dot resolution removes the potential for an ambiguous behaviour when the child directory is entered using an alternate path. This ambiguity is inherent to UNIX-like systems and, if not dealt with by the shell, the following scenario is possible:
 
 {{{
+[jermar@gorgo tmp]$ mkdir -p foo/bar/foobar
+[jermar@gorgo tmp]$ ln -s foo/bar bar2
+[jermar@gorgo tmp]$ csh
+[jermar@gorgo /tmp]$ cd bar2
+
+[jermar@gorgo bar2]$ cd ../bar2
+../bar2: No such file or directory.
+[jermar@gorgo bar2]$ pwd
+/tmp/foo/bar
+}}}
+
+With lexical dot-dot resolution we see the following `bash` session output:
+
+{{{
+[jermar@gorgo tmp]$ bash
+[jermar@gorgo tmp]$ cd bar2
+[jermar@gorgo bar2]$ cd ../bar2
+[jermar@gorgo bar2]$ pwd
+/tmp/bar2
 }}}