fish-shell/share/completions/kldload.fish
Mahmoud Al-Qudsi 4d7ef1fad8 Speed up kldload descriptions with alternative to __fish_whatis
__kld_whatis is an order of magnitude faster than calling `whatis` by means of
`__fish_whatis`. (It could be even faster if we could somehow tell `string
replace` to return after the first result, since the .Nd line comes at the start
of the file.)

It still takes some ~3.5 to print descriptions for all available klds (864 under
FreeBSD 13), so we still need to decide when it's prudent to do so and when it's
not.
2024-06-24 15:21:06 -05:00

39 lines
1.9 KiB
Fish

# Completions for the FreeBSD `kldload` kernel module load utility
function __fish_list_kldload_options
set -l klds (__fish_complete_suffix --complete=/boot/kernel/(commandline -ct) ".ko" | string replace -r '.*/(.+)\\.ko' '$1')
# Completing available klds is fast, but completing it with a call to __fish_whatis
# is decidedly not. With 846 modules (FreeBSD 11.1), fish --profile 'complete -C"kldload "' returns the following:
# 10671 11892698 > complete -C"kldload "
# A 12 second completion delay is obviously out of the question, so don't provide a description unless there are
# fewer than 50 results. (Update: now 200 after the switch to __kld_whatis.)
# Additionally, we can halve the time by not shelling out to `whatis` if we know the man file for the kernel module
# in question does not exist, since the paths are hardcoded.
set -l kld_count (count $klds)
if test $kld_count -le 200 -a $kld_count -gt 0
# print name and description
for kld in $klds
printf '%s\t%s\n' $kld (test -f /usr/share/man/man4/$kld.4.gz;
and __kld_whatis $kld; or echo "kernel module")[1]
end
else if test $kld_count -gt 0
# print name only
printf '%s\n' $klds
else
# print name only (description won't exist since the kernel module isn't installed)
__fish_complete_suffix .ko
end
end
# This is up to 10-50x faster than using __fish_whatis but it could someday break.
# (zcat is part of the standard FreeBSD distribution.)
# Without this, we can't reasonably show descriptions for most completions within our time budget.
function __kld_whatis
set -l kld $argv[1]
set -l path /usr/share/man/man4/$kld.4.gz
zcat $path | string replace -rf '\.Nd "?([^"]+).*' '$1'
end
# Only attempt to match a local file if there isn't a match in /boot/kernel,
# as odds are that is the desired source.
complete -c kldload -xa '(__fish_list_kldload_options)'