How to get a file size (and other attributes) in Common Lisp?

How do we get file attributes ? I primarily am looking to get the size, but also its last access time and other attributes.

I only found (file-length some-file) that gets a stream so is used this way:

(with-open-file (file "some file name") 
  (file-length file))

Looks to be doing the job but:

it gets a stream: this is uncoherent with the rest of the api
there really are no shorter function ??
(is it the most efficient way to do ?)

I see nothing related to a file length or attributes in Osicat. Maybe is it its role and I'll fill a feature request ?

Practical CL talks about file-length and refers to Osicat and that's it.

No more info on the CL cookbook, no more "posix" or "file" related material on the awesome-cl list.

I would appreciate something like in elisp.

thanks

edit: maybe on iolib but it looks like its online doc is uncomplete and not talking about files even though it announces to having "a pathname library and file-system utilities". But apparently it does not have do what I'm looking for: https://github.com/sionescu/iolib/blob/master/src/os/os-unix.lisp

Solution

With Osicat, you call stat on the file and you get a bunch of things in a structure:

(describe (osicat-posix:stat #P"/tmp/file"))

#<OSICAT-POSIX:STAT {1004F20C93}>
  [standard-object]

Slots with :INSTANCE allocation:
  DEV      = 2065
  INO      = 7349974
  MODE     = 33204
  NLINK    = 1
  UID      = 1000
  GID      = 1000
  RDEV     = 0
  SIZE     = 4304
  BLKSIZE  = 4096
  BLOCKS   = 16
  ATIME    = 1497626097
  MTIME    = 1497347216
  CTIME    = 1497347216
; No value

You can access the different slots with the following functions :

osicat-posix:stat-dev
osicat-posix:stat-gid                        
osicat-posix:stat-ino                        
osicat-posix:stat-uid                        
osicat-posix:stat-mode                       
osicat-posix:stat-rdev                       
osicat-posix:stat-size                       
osicat-posix:stat-atime                      
osicat-posix:stat-ctime                      
osicat-posix:stat-mtime                      
osicat-posix:stat-nlink                      
osicat-posix:stat-blocks                     
osicat-posix:stat-blksize