Image Previews and Shell Integration for lf

Getting-started guide to a basic lf setup for previews of images, documents and video thumbnails aswell as shell integration to change the working directory with lf.

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UPDATE Recent additions to lf's shell interface allow to set up image previews and shell integration in a much cleaner fashion than the method shown below. See https://github.com/slavistan/lf-gadgets/tree/master/lf-ueberzug for the updated instructions. Note that the setup below remains fully functional, albeit unnecessarily complex.

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Prerequesites:

• golang (to install from source)
• ueberzug
• imagemagick (for .svg previews)
• ffmpeg (for video file thumbnails)
• gs (for pdf previews)

1. Install lf

Get the source code, build and install.

git clone "https://github.com/gokcehan/lf" .
go install

Make sure lf can be run. Copy $GOPATH/bin/lf to usr/local/bin/ if your $GOPATH is not in your $PATH.

2. Install lf wrapper, preview and cleaner scripts

Install the 3 scripts lf-run, lf-cleaner and lf-previewer from this repository. Make sure they're executable and in your $PATH.

3. Configure your shell

Add this function to your .zshrc (or .bashrc etc.) to set up ueberzug previews and to give you the option of changing your working directory upon exiting lf.

# zshrc or bashrc
lf () {
	LF_TEMPDIR="$(mktemp -d -t lf-tempdir-XXXXXX)"
	LF_TEMPDIR="$LF_TEMPDIR" lf-run -last-dir-path="$LF_TEMPDIR/lastdir" "$@"
	if [ "$(cat "$LF_TEMPDIR/cdtolastdir" 2>/dev/null)" = "1" ]; then
		cd "$(cat "$LF_TEMPDIR/lastdir")"
	fi
	rm -r "$LF_TEMPDIR"
	unset LF_TEMPDIR
}

4. Configure lf

In your lfrc configure your previewer and cleaner settings and choose a hotkey to quit lf and change your working directory.

set previewer lf-previewer
set cleaner lf-cleaner

map x quitcd
cmd quitcd ${{
	echo "1" > "$LF_TEMPDIR"/cdtolastdir
	lf -remote "send $id quit"
}}

Using the above, pressing x will change your working directory after you quit lf while q won't (lf's default behavior). If you prefer to always change your working directory upon closing lf map quitcd to q instead.

Done!

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Further Information

Note that if you want to start lf from a different shell or a script you must run lf-run instead of lf. Failing to do so will skip the proper set up of ueberzug and its temporary directory and lf's attempts to generate previews will produce error messages.

The proper way to configure lf to work with and without the setup in lf-run is to separate configurations for when lf was launched through lf-run vs. when lf was launched directly. This can be done using shell blocks inside your lfrc. Here's a template to get you started which will print a message and exit immediately if lf is started without lf-run.

# lfrc
%{{
if [ -z "$LF_TEMPDIR" ] || [ -z "$LF_FIFO_UEBERZUG" ]; then
	# lf was launched directly without lf-run
	lf -remote "send $id \$echo 'Did you run lf instead of lf-run?'"
	lf -remote "send $id quit"
else
	# lf was launched through lf-run
fi
}}