How can I found out if file is alias or symbolic link?

I'm working on a legacy system and I have a bunch of files that are referencing images that are located in other folders.

lrwxrwxrwx  1 user nobody      56 Feb 10  2010 t100x100.jpg -> /home/www/virtual/categories/swm/24/m/00012/t100x100.jpg
lrwxrwxrwx  1 user nobody      56 Feb 10  2010 t100x133.jpg -> /home/www/virtual/categories/swm/24/m/00012/t100x133.jpg
lrwxrwxrwx  1 user nobody      56 Feb 10  2010 t125x150.jpg -> /home/www/virtual/categories/swm/24/m/00012/t125x150.jpg
lrwxrwxrwx  1 user nobody      56 Feb 10  2010 t150x200.jpg -> /home/www/virtual/categories/swm/24/m/00012/t150x200.jpg

How can I know if these are symbolic links or aliases?

Solution 1:

Symbolic links:

lrwxrwxrwx  1 user nobody      56 Feb 10  2010 t100x100.jpg -> /home/www/virtual/categories/swm/24/m/00012/t100x100.jpg
^
 ` Here it is, l for symbolic link.

If you files are hard links then they show up just as other files. For example every directory has directory named . hardlinked to it.

From $ man find:

Each directory on a normal Unix filesystem has at least 2 hard links: its name and its .' entry. Additionally, its subdirectories (if any) each have a..' entry linked to that directory.

Hard links:

-rw-r--r--  3 root root   60 2012-06-25 12:17 File
-rw-r--r--  3 root root   60 2012-06-25 12:17 HardLinkToFile
-rw-r--r--  3 root root   60 2012-06-25 12:17 HardLinkToFile2
lrwxrwxrwx  1 user nobody      56 Feb 10  2010 t100x100.jpg -> /home/www/virtual/categories/swm/24/m/00012/t100x100.jpg
            ^
             ` This number is hard link (reference) count.

Solution 2:

The file or stat commands will tell you what a file is:

$ ln -s /home this_is_a_link
$ touch this_is_not_a_link
$ file this_*
this_is_a_link:     symbolic link to `/home'
this_is_not_a_link: empty
$ stat this_*
  File: `this_is_a_link' -> `/home'
  Size: 5               Blocks: 0          IO Block: 4096   symbolic link
Device: ca00h/51712d    Inode: 106983      Links: 1
Access: (0777/lrwxrwxrwx)  Uid: ( 1000/    andy)   Gid: ( 1000/    andy)
Access: 2012-07-29 23:28:17.000000000 +0000
Modify: 2012-07-29 23:28:17.000000000 +0000
Change: 2012-07-29 23:28:17.000000000 +0000
  File: `this_is_not_a_link'
  Size: 0               Blocks: 0          IO Block: 4096   regular empty file
Device: ca00h/51712d    Inode: 106992      Links: 1
Access: (0644/-rw-r--r--)  Uid: ( 1000/    andy)   Gid: ( 1000/    andy)
Access: 2012-07-29 23:28:27.000000000 +0000
Modify: 2012-07-29 23:28:27.000000000 +0000
Change: 2012-07-29 23:28:27.000000000 +0000

If scripting, the test command may be of more use:

   -h FILE
         FILE exists and is a symbolic link (same as -L)

$ for f in this_*; do if test -h "$f"; then echo "$f is a symlink"; else echo "$f is not a symlink"; fi; done
this_is_a_link is a symlink
this_is_not_a_link is not a symlink