Can the temp gzip decompression location for the integrated help documents be changed from /tmp?

Question

Is it possible to configure vi to use a different location, say my home directory, for the uncompressed help files (or maybe to open them in RO if that's the problem)?

When attempting to open a help document from within vi I get the following error:

"quickref.txt.gz" [readonly][noeol] 94L, 21071C
Error detected while processing function gzip#read:
line   41:
E484: Can't open file /tmp/vcl6GTZ/7
Press ENTER or type command to continue
Error detected while processing function gzip#read:
line   44:
Error: Could not read uncompressed file
Press ENTER or type command to continue
E434: Can't find tag pattern
Press ENTER or type command to continue

This happens when pressing CTRL+] over quickref from help.txt (:help):

Instead, the raw, uncompressed help.txt.gz file is opened and displayed:

I was told by the company hosting this server that I don't have access to tmp (though I can ls it's contents).

---

Update (11/15/2019)

After adding $TMPDIR to env with export TMPDIR=~/tmp I now get the following error (same error, different location). Maybe the underlying issue is with the "tag pattern" not being found, which occurs irrespective of the temp path's location:

"quickref.txt.gz" [readonly][noeol] 94L, 21071C
Error detected while processing function gzip#read:
line   41:
E484: Can't open file /home1/<username>/tmp/vNQn0ab/3
Press ENTER or type command to continue
Error detected while processing function gzip#read:
line   44:
Error: Could not read uncompressed file
Press ENTER or type command to continue
E434: Can't find tag pattern
Press ENTER or type command to continue

Answer 1

I've done some digging. (tpope's scriptease makes this really easy.)

plugin/gzip.vim reveals that most of the functionality is autoloaded.

autoload/gzip.vim reveals that the temporary paths are constructed using tempname().

tempname() reveals that *tempfile* has the appropriate help:

Vim uses temporary files for filtering, generating diffs and also for
tempname().  For Unix, the file will be in a private directory (only
accessible by the current user) to avoid security problems (e.g., a symlink
attack or other people reading your file).  When Vim exits the directory and
all files in it are deleted.  When Vim has the setuid bit set this may cause
problems, the temp file is owned by the setuid user but the filter command
probably runs as the original user.
On MS-DOS and OS/2 the first of these directories that works is used: $TMP,
$TEMP, c:\TMP, c:\TEMP.
For Unix the list of directories is: $TMPDIR, /tmp, current-dir, $HOME.
For MS-Windows the GetTempFileName() system function is used.
For other systems the tmpnam() library function is used.

So, at least on *nix systems, you should be able to set the TMPDIR environment variable.

Note that other programs may use this variable too, so you may want to only set it for vim:

" vimrc or other
let $TMPDIR = ...

But any :terms you start will inherit this (I'm not sure if it is exported, though, so I am not sure if other programs running from a shell could see it. printenv sees it, at least.)

Answer 2

Yes, it is possible to override the location where the temporary decompressed files are stored.

On Unix-like platforms (including Linux or Mac OS), you can do so by setting the $TMPDIR environment variable, which you can either do from your vimrc file, or from your .bashrc or similar.

Assuming you create a ~/tmp directory:

$ mkdir ~/tmp

Then you can use the following in your vimrc:

let $TMPDIR = expand('~/tmp')

Or define the environment variable in your .bashrc or similar:

export TMPDIR=~/tmp

(Exporting it in your shell is probably better, since there are other tools that depend on a writable temporary directory and that might the same variable setting, so they'd benefit from this configuration too.)

For more details, see :help tempfile on how Vim will look for a temporary directory and how it varies per platform.

You might also want to check :help tempname(), which is the Vimscript function used by the gzip.vim module to find a temporary directory. And :help expand() which was mentioned above.