z history is pruned if a filesystem is not mounted

[systemmonkey42]

Issue: If I use z when a filesystem (like /home) is unmounted, all references to /home are instantly purged from the cd history.

This has caught me out enough times ( I have a 100TB zfs pool I unmount for maintenance occasionally ) that I use a patched z which tracks the mountpoint.

Missing paths are filtered as normal when deciding where to go, but paths are only deleted if they are missing AND the mountpoint is actually mounted.

[rupa]

not opposed to a way to deal with this, but not 100 sure how I'd go about it. If you want to share your patch maybe I'll get inspired :) (or a PR if your implementation is tidy)

[systemmonkey42]

Hi

Unfortunately my code isn't a "patch" to your code, but more of a reimplementation "inspired" by z which suits my needs.

The mountpoint stuff is also linux specific in that it reads /proc/self/mounts rather than parsing the output of df, but I'm pretty sure they are very similar (make sure you use the -P flag on df if it is supported on the platform you are using.)

The logic was simple:

• When "adding", check the mountpoint a path is under, and save that as a column
  • eg, /home/user/work/project/test -> saved as /home|/home/usr/work/project/test|...
• When scanning the z history file, get awk to pre-load the list of mountpoints
  • eg. awk 'BEGIN{while("df -P" | getline ) { mount[$NF]=1 }}{...}'
  • When the first field (mountpoint) isnt in 'mounts', ignore it when picking a directory to go to, and avoid pruning it when adding (but age it out, in case it never comes back).

Regards

[agkozak]

My ZSH-z plugin accomplishes this by having a ZSHZ_KEEP_DIRS array of directories that should never be removed and whose subdirectories should never be removed. Something similar could be done in the _z_dirs function.