setting the name of the swap file?

Hi,

Is it possible to change the name of the swap file that Vim uses?

I have just started using a centralized location for swapfiles with the

'directory' option.  However, I am running into a problem of name space

collision, or lack of same.

Often I edit files with the same name in different directories.  Vim allows

this and has no problem creating two different swap files in the same dir.

However, this can cause a problem in a crash.

Example:

   1) editing /a/x.txt and /b/x.txt (directory set to .../swap)

   2) vim creates .../swap/x.txt.swp (for /a/x.txt) 

              and .../swap/x.txt.swo (for /b/x.txt)

   3) normally this is fine and vim tracks which swap file is for

      which file.

   4) vim crash (for whatever reason)

   5) now we try to edit /a/x.txt and vim sees x.txt.swp and prompts to

      recover, good as expected.

   6) We save the file and delete x.txt.swp

   7) now we edit /b/x.txt, vim looks in .../swap and does not see

      x.txt.swp (it does not know to look for x.txt.swo which is the

      correct swap for the file being edited) and happily lets you

      edit the corrupted file <-- FAIL

   

What I would like to do is create a function to prepend a dir "hash" to

the name of the swap file so that even in the scenario above the files

would have unique swap file names and this problem would be averted. 

My idea is to use the first letter of each segment of the path of the

file prepended to the swap file name (ex: swap files from above would be

a_x.txt.swp and b_x.txt.swp, editing /foo/bar/baz.txt would use the swap

file fb_baz.txt.swp) While fairly simplistic this would resolve the

problem in most cases.

Before I start wring this function, I want to know if it is even possible

to change the name of the swap file. Also, ideally I would want to keep

the original vim functionality of .swp .swo .swn .swm ... for reediting

the same file.

Thanks,

Matt

From VIM's man-page:

    By setting the 'directory' option you can place the swap file in

    another place than where the edited file is.

    Advantages:

      - You will not pollute the directories with ".swp" files.

    Disadvantages:

      - You can get name collisions from files with the same name but in

        different directories (although Vim tries to avoid that by

        comparing the path name).