Summary

##sys#expand-home-path bug on OS X

Metadata

Attachments

Description

Plain tilde does not work properly. Did not check any other platform yet. Pretty sure this has been present forever.

 #;2> (##sys#expand-home-path "~/tmp")
 "/Users/jim/tmp"
 #;3> (##sys#expand-home-path "~/")
 "/Users/jim/"
 #;4> (##sys#expand-home-path "~")
 "/home/"

Also affects derived procedures e.g.

 #;3> (change-directory "~/tmp")
 #;4> (change-directory "~")
 Error: (change-directory) cannot change current directory - No such file or directory: "~"

Changes and comments

[2009-06-28 01:11:47 UTC] zbigniew wrote:

OK, I see this is done to support ~user -> /home/user, which can't be done reliably without getpwnam(3).

I would be satisfied with the simple fix of "~" -> (getenv "HOME"), while leaving "~user" broken, in ##sys#expand-home-path. As you probably wish to avoid a getpwnam call in library.scm.

However, the posix unit should really have its own expansion code used by change-directory etc., which uses getpwnam / getpwuid for tilde expansion.

I could produce a patch if you are interested.

[2009-06-28 04:35:57 UTC] zbigniew wrote:

Attached an attempt at fixing this. Creates a new parameter ##sys#tilde-expander used by ##sys#expand-home-path which, by default, just checks $HOME, but when the posixunix unit is loaded, will use either $HOME or user-information. posixwin currently uses the default behavior. Also if tilde-expansion fails the original unexpanded text will be used. it will do ~/tmp -> /tmp if $HOME is unset.

I did not touch canonical-path, which is also broken (worse). It is a bit hairy but could piggyback on this.

expand-home-path fix example

 $ echo $HOME
 /Users/jim
 $ csi
 #;1> (##sys#expand-home-path "~")
 "/Users/jim"
 #;2> (##sys#expand-home-path "~jim")
 "/home/jim"
 #;3> (##sys#expand-home-path "~root")
 "/home/root"
 #;3> (##sys#expand-home-path "~/tmp")
 "/Users/jim/tmp"
 #;4> (use posix)
 ; loading library posix ...
 #;5> (##sys#expand-home-path "~")
 "/Users/jim"
 #;6> (##sys#expand-home-path "~jim")
 "/Users/jim"
 #;7> (##sys#expand-home-path "~/tmp")
 "/Users/jim/tmp"
 #;10> (##sys#expand-home-path "~root")
 "/var/root"
 #;11> (##sys#expand-home-path "~dummy")
 "~dummy"
 #;12> (unsetenv "HOME")
 #;13> (##sys#expand-home-path "~")
 "/Users/jim"
 #;14> (setenv "HOME" "/dummy")
 #;15> (##sys#expand-home-path "~/tmp")
 "/dummy/tmp"
 
 $ unset HOME; csi
 #;1> (##sys#expand-home-path "~")
 "~"
 #;1> (##sys#expand-home-path "~/tmp")
 "~/tmp"

Broken canonical-path example

 #;2> (use posix)
 #;3> (canonical-path "~")
 "/Users/jim/~"
 #;4> (canonical-path "~/")
 "/Users/jim/"
 #;8> (canonical-path "~jim")
 "/Users/jim/~jim"
 #;9> (canonical-path "~/tmp")
 "/Users/jim/tmp"

[2009-06-28 04:47:36 UTC] zbigniew attached tilde-expander.diff.txt (description=patch to svn trunk)

[2009-06-29 15:25:15 UTC] felix changed status from new to assigned

[2009-06-29 15:25:15 UTC] felix set owner to felix

[2009-06-30 10:42:17 UTC] felix changed status from assigned to closed

[2009-06-30 10:42:17 UTC] felix set resolution to fixed

[2009-06-30 10:42:17 UTC] felix wrote:

"~user" was never officially supported - I can't remember, whether I added the "/home/" brokenness or not.

I will simply remove this feature - an initial "~" will expand into $HOME. `canonical-path` will be folded into `normalize-pathname` and simplified later.

See commit r15118