announcement : link-batch.zsh, to generate symlinks batches

cross-posted from: lemmy.world/post/1838642

link-batch is a minimalist script that generate symlinks from a list in a text file. Usage :
<pre style="background-color:#ffffff;">
link-batch.zsh link-list.txt

where link-list.txt contains two columns : the first one for the links and the second one for the targets. Example :
<pre style="background-color:#ffffff;">
~/.config/kitty	~/myfiles/config/kitty
~/.config/nvim	~/myfiles/config/neovim
~/.config/MuseScore	~/myfiles/config/MuseScore/$HOST
...

The two columns must be separated by a tab.

Shell vars like $HOME or $HOST are evaluated to their values.

Can be used to quickly deploy all home links in a fresh box.

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gamma, 10 months ago

Nice work! I would have done some things differently, but this is very readable.

Two recommendations for reading the file:

Use the (z) and (Q) flags so that instead of using tabs to separate the targets, simply quoting each argument works.
Instead of two independent lists, use an associative array with map[$link]=$target. Then you can check for duplicate links while reading the list.

<pre style="background-color:#ffffff;">
<span style="color:#323232;">linksfile</span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#183691;">$</span><span style="color:#323232;">1
</span><span style="color:#323232;">
</span><span style="font-weight:bold;color:#a71d5d;">typeset </span><span style="color:#323232;">-gA linkmap
</span><span style="color:#323232;">
</span><span style="font-weight:bold;color:#a71d5d;">while </span><span style="color:#62a35c;">read </span><span style="color:#323232;">-r line
</span><span style="font-weight:bold;color:#a71d5d;">do
</span><span style="color:#323232;">	</span><span style="font-style:italic;color:#969896;"># -- fields
</span><span style="color:#323232;">	fields</span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#323232;">(${(Q)${(z)line}})
</span><span style="color:#323232;">	</span><span style="font-style:italic;color:#969896;"># -- link
</span><span style="color:#323232;">	link</span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#183691;">${</span><span style="color:#323232;">(e)~fields[</span><span style="color:#0086b3;">1</span><span style="color:#323232;">]</span><span style="color:#183691;">}
</span><span style="color:#323232;">	</span><span style="font-style:italic;color:#969896;"># -- target
</span><span style="color:#323232;">	target</span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#183691;">${</span><span style="color:#323232;">(e)~fields[</span><span style="color:#0086b3;">2</span><span style="color:#323232;">]</span><span style="color:#183691;">}
</span><span style="color:#323232;">	</span><span style="font-style:italic;color:#969896;"># -- check if we've already seen this link
</span><span style="color:#323232;">	</span><span style="font-weight:bold;color:#a71d5d;">if </span><span style="color:#323232;">(( $</span><span style="font-weight:bold;color:#a71d5d;">+</span><span style="color:#323232;">linkmap[$link] ))</span><span style="font-weight:bold;color:#a71d5d;">; then
</span><span style="color:#323232;">		</span><span style="color:#62a35c;">echo </span><span style="color:#183691;">"'$</span><span style="color:#323232;">link</span><span style="color:#183691;">' targets both '$</span><span style="color:#323232;">linkmap</span><span style="color:#183691;">[$</span><span style="color:#323232;">link</span><span style="color:#183691;">]' and '$</span><span style="color:#323232;">target</span><span style="color:#183691;">', aborting"
</span><span style="color:#323232;">		</span><span style="color:#62a35c;">exit</span><span style="color:#323232;"> 1
</span><span style="color:#323232;">	</span><span style="font-weight:bold;color:#a71d5d;">fi
</span><span style="color:#323232;">	</span><span style="font-weight:bold;color:#a71d5d;">if </span><span style="color:#62a35c;">[ </span><span style="color:#323232;">-z </span><span style="color:#183691;">"$</span><span style="color:#323232;">target</span><span style="color:#183691;">" </span><span style="color:#62a35c;">] </span><span style="font-weight:bold;color:#a71d5d;">|| </span><span style="color:#62a35c;">[ </span><span style="color:#323232;">-z </span><span style="color:#183691;">"$</span><span style="color:#323232;">link</span><span style="color:#183691;">" </span><span style="color:#62a35c;">]</span><span style="font-weight:bold;color:#a71d5d;">; then
</span><span style="color:#323232;">		</span><span style="color:#62a35c;">echo </span><span style="color:#183691;">"Empty link or target provided, skipping"
</span><span style="color:#323232;">		</span><span style="font-weight:bold;color:#a71d5d;">continue
</span><span style="color:#323232;">	</span><span style="font-weight:bold;color:#a71d5d;">fi
</span><span style="color:#323232;">	linkmap[$link]</span><span style="font-weight:bold;color:#a71d5d;">=</span><span style="color:#183691;">$</span><span style="color:#323232;">target
</span><span style="font-weight:bold;color:#a71d5d;">done < </span><span style="color:#323232;">$linksfile
</span>

Then later, you can iterate over each key-value pair:

<pre style="background-color:#ffffff;">
<span style="font-weight:bold;color:#a71d5d;">for</span><span style="color:#323232;"> link target </span><span style="font-weight:bold;color:#a71d5d;">in </span><span style="color:#183691;">"${</span><span style="color:#323232;">(@kv)linkmap</span><span style="color:#183691;">}"</span><span style="font-weight:bold;color:#a71d5d;">; do
</span><span style="color:#323232;">	...
</span><span style="font-weight:bold;color:#a71d5d;">done
</span>

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