Previewer for the LF CLI File Manager

This is a simple previewer for the LF File Manager.

It detects file type based on the file extension and then uses the appropriate previewer to display the file in the terminal.

Sample preview of it working in tandem with lf:

Note that this tool does not do any actual previewing by itself. It is just a wrapper around other previewers.

Usage:

You can run pv on it's own:

pv filename

This will simply output the preview of the file to the terminal:

scr2

The program supports a couple of basic command line switches:

Usage: pv.exe <file>
Options:
    -v, --version   Show version
    -h, --help      Show this help
    -c, --config    Show configuration

While it works as a stand alone program, pv has been designed specifically to work in tandem with lf in lieu of a shell specific script.

To configure pv to be the default previewer for lf add the following line to your lfrc config file:

set previewer pv

Configuration

You can configure the previewers and their arguments by creating a config file named .pvrc

On Linux, Unix and Mac put it in ~/.pvrc
On Windows put it in %USERPROFILE%\.pvrc

The format of the config file is simple:

key=value

No spaces!

Here is an example:

text_viewer=bat
text_viewer_opts=--color=always
text_viewer_args=--theme=dracula

This will result in pv calling the previewer application bat when it is asked to open a text file. It will do so in the following way:

bat --color=always <file> --theme=dracula

Each _viewer has a corresponding _args and _opts setting, both of which are optional and only need to be specified if you want to override the defaults. Both are used to pass additional arguments to the viewer executable. The difference is as follows:

The _opts are arguments or subcommands that are passed in before the file path
The _args are trailing arguments that are passed in after the file path

This is important, because some programs have positional arguments for input and output files.

You can check the current configuration by running:

pv -c

This will output the current configuration and corresponding opt and arg values.

Viewers

Following viewers are available to be overriden. Each one is listed alongside the the extensions that it is associated with:

Viewer	Extensions
`image_viewer`	`jpg` `jpeg` `png` `gif` `bmp` `tiff` `svg` `webp` `ico` `jit` `jif` `jfi`
`md_viewer`	`md` `markdown` `mkd` `mkdn` `mdwn` `mdown` `mdtxt`
`pdf_viewer`	`pdf`
`music_viewer`	`mp3` `flac` `wav` `ogg` `m4a` `wma` `aac` `aiff` `alac` `ape` `dsd` `dts` `mka` `mpc` `ofr` `.ofs` `opus` `tak` `tta` `wv`
`video_viewer`	`mp4` `mkv` `webm` `avi` `mov` `wmv` `flv` `3gp` `mpg` `mpeg` `m2v` `m4v` `m2ts` `ts` `mts` `vob` `divx` `xvid` `rm` `rmvb` `asf` `ogv` `3g2` `f4v` `h264` `h265` `hevc` `vp9` `vp8` `av1`
`zip_viewer`	`zip` `jar`
`sevenz_viewer`	`7z`
`rar_viewer`	`rar`
`word_viewer`	`doc` `docx` `odt` `rtf`
`excel_viewer`	`xlsx`
`web_viewer`	`html` `htm` `xhtml` `mhtml` `mht`
`exe_viewer`	`exe` `dll` `msi` `sys` `msx`
`text_viewer`	`txt`
`log_viewer`	`log`
`tar_viewer`	`tar`
`gz_viewer`	`gz`
`xz_viewer`	`xz`
`bzip2_viewer`	`bz2`
`ebook_viewer`	`epub` `epub3` `mobi` `azw` `azw3` `fb2`
`naked_viewer`	Used when a file has no extension
`default_viewer`	Used when the file extension does not match any of the above

Currently there is no way to change the file extension association via the configuration file, they are hard coded.

The _viewer option needs to be set to a string that represents a file name of an actual executable (or an executable script) file. This file:

must be in your $PATH (or %PATH%)
must output directly to stdout

Defaults

Current defaults are:

    image_viewer:     chafa <file>
    text_viewer:      bat --color=always <file> --theme=dracula
    md_viewer:        glow --style=dracula <file>
    pdf_viewer:       pdftotext <file> -
    music_viewer:     exiftool
    video_viewer:     exiftool
    zip_viewer:       unzip -l <file>
    sevenz_viewer:    7z l <file>
    rar_viewer:       unrar l <file>
    word_viewer:      pandoc --to=plain <file>
    excel_viewer:     xlsx2csv -o=- <file>
    web_viewer:       lynx -dump <file>
    exe_viewer:       hyxel <file>
    log_viewer:       bat --color=always <file>
    tar_viewer:       tar -tvf <file>
    gz_viewer:        tar -ztvf <file>
    xz_viewer:        tar -Jtvf <file>
    bz2_viewer:       tar -jtvf <file>
    ebook_viewer:     epy -d <file>
    naked_viewer:     bat --color=always <file>
    defaultviewer:    bat --color=always <file>

Using bat as the default_viewer is recommended as it usually works well with most file types (even binary ones).

The naked_viewer option is set to bat by default as files with no extension are just as likely to be binary executables as they are to be shell scripts.

Overriding Default Arguments

To override the default _opt or _arg value for a specific viewer, simply provide a new one in the config file. To override it with nothing, put nothing after the = sign like this:

text_viewer_opts=
text_viewer_args=

Depedencies

You need a previewer for each file type.

The default previewers are:

bat (default viewer)
chafa (for images)
glow (for markdown files)
exiftool (for audio and video files)
poppler (for pdf files)
pandoc (for word and rtf files)
lynx (for html files)
hyxel (for exe files)
epy (for ebook files)
For archive files you need: unzip, 7z, unrar and tar

Installation

Via Go

Install via go:

go install github.com/maciakl/pv@latest

On Linux

One liner to fetch and install the binary into /usr/local/bin:

p="pv" && wget -qN "https://github.com/maciakl/${p}/releases/latest/download/${p}_lin.zip" && unzip -oq ${p}_lin.zip && rm -f ${p}_lin.zip && chmod +x ${p} && sudo mv ${p} /usr/local/bin

On Windows

First get scoop.

Then add my bucket and install pv:

scoop bucket add maciak https://github.com/maciakl/bucket
scoop update
scoop install pv

To install all the default previewers do:

scoop install lf
scoop install bat
scoop install chafa
scoop install glow
scoop install exiftool
scoop install poppler
scoop install pandoc
scoop install lynx
scoop install unzip
scoop install 7z
scoop install unrar
scoop install hyxel
scoop install busybox
scoop install pipx
pipx install epy

# README