When you edit multiple md files remotely, like in a larger mkdocs project, context switches between editing terminal(s) and viewing browser may have some efficiency impact. Also sometimes there is just no browser, like via security gateways offering just a fixed set of applications on the hop in machine. Further, reading efficiency and convenience is often significantly improved by using colors. And lastly, using such a thing for cli applications might improve user output, e.g. for help texts.
This is where mdv, a Python based Markdown viewer for the terminal might be a good option.
If markdown is often "simple" enough to be somewhat readable on 256 color terminals (except images that is).
from
### Source
# Header 1
## Header 2
### Header 3
#### Header 4
##### Header 5
###### Header 6
```python
""" Test """
# Make Py2 >>> Py3:
import os, sys; reload(sys); sys.setdefaultencoding('utf-8')
# no? see http://stackoverflow.com/a/29832646/4583360 ...
# code analysis for hilite:
try:
from pygments import lex, token
from pygments.lexers import get_lexer_by_name, guess_lexer
```
| Tables | Fmt |
| -- | -- |
| !!! hint: wrapped | 0.1 **strong** |
!!! note: title
this is a Note
You can also use mdv as a source code viewer, best when you have docstrings with markdown in your code:
from
~/terminal_markdown_viewer $ cat setup.py
#!/usr/bin/env python2.7
# coding: utf-8
"""_
# Mdv installation
## Usage
[sudo] ./setup.py install
----
"""
from setuptools import setup, find_packages
import mdv
setup(
name='mdv',
version=mdv.__version__,
(the '_' after the docstring telling mdv that markdown follows)
mdv is a proof of concept hack: While for simple structures it does its job quite well, for complex markdown you want to use other tools. Especially for inlined html it simply fails.
The ones I know of (and which made me write mdv ;-) ):
Summary: For production ready robust markdown viewing (e.g. for your customers) I recommend nd still, due to the early state of mdv. For playing around, especially with theming or when with Python, this one might be a valid alternative to look at.
pip install mdv
If you get no attribute HTML_PLACEHOLDER: update your markdown package.
Here is a macport (thanks Aljaž).
mdv is also available in the FreeBSD package repositories via pkg install py36-mdv (the Python version might change in the future).
Further a 256 color terminal (for now best with dark background) and font support for a few special separator characters (which you could change via config).
For light terms you'd just need to revert the 5 colors from the themes, since they are sorted by luminocity.
I did not test anything on windows.
# Usage:
mdv [OPTIONS] MDFILE
# Options:
MDFILE : Path to markdown file
-A : Strip all ansi (no colors then)
-C MODE : Sourcecode highlighting mode
-H : Print html version
-L : Backwards compatible shortcut for '-u i'
-M DIR : Monitor directory for markdown file changes
-T C_THEME: Theme for code highlight. If not set: Using THEME.
-X Lexer : Default lexer name (default: python). Set -x to use it always.
-b TABL : Set tab_length to sth. different than 4 [default: 4]
-c COLS : Fix columns to this (default: your terminal width)
-f FROM : Display FROM given substring of the file.
-h : Show help
-i : Show theme infos with output
-l : Light background (not yet supported)
-m : Monitor file for changes and redisplay FROM given substring
-n NRS : Header numbering (default: off. Say e.g. -3 or 1- or 1-5
-t THEME : Key within the color ansi_table.json. 'random' accepted.
-u STYL : Link Style (it=inline table=default, h=hide, i=inline)
-x : Do not try guess code lexer (guessing is a bit slow)
# Notes:
We use stty tool to derive terminal size. If you pipe into mdv we use 80 cols.
## To use mdv.py as lib:
Call the main function with markdown string at hand to get a
formatted one back. Sorry then for no Py3 support, accepting PRs if they don't screw Py2.
## FROM:
FROM may contain max lines to display, seperated by colon.
Example:
-f 'Some Head:10' -> displays 10 lines after 'Some Head'
If the substring is not found we set it to the *first* character of the file -
resulting in output from the top (if your terminal height can be derived correctly through the stty cmd).
## Code Highlighting
Set -C <all|code|doc|mod> for source code highlighting of source code files.
Mark inline markdown with a '_' following the docstring beginnings.
- all: Show markdown docstrings AND code (default if you say, e.g. `-C.`)
- code: Only Code
- doc: Only docstrings with markdown
- mod: Only the module level docstring
## File Monitor:
If FROM is not found we display the whole file.
## Directory Monitor:
We check only text file changes, monitoring their size.
By default .md, .mdown, .markdown files are checked but you can change like `-M 'mydir:py,c,md,'` where the last empty substrings makes mdv also monitor any file w/o extension (like 'README').
### Running actions on changes:
If you append to `-M` a `'::<cmd>'` we run the command on any change detected (sync, in foreground).
The command can contain placeholders:
_fp_ # Will be replaced with filepath
_raw_ # Will be replaced with the base64 encoded raw content
of the file
_pretty_ # Will be replaced with the base64 encoded prettyfied output
Like: mdv -M './mydocs:py,md::open "_fp_"' which calls the open
command with argument the path to the changed file.
## Themes
### Theme Rollers
mdv -T all [file]: All available code styles on the given file.
mdv -t all [file]: All available md styles on the given file.
If file is not given we use a short sample file.
So to see all code hilite variations with a given theme:
Say C_THEME = all and fix THEME
Setting both to all will probably spin your beach ball...
### Environ Vars
`$MDV_THEME` and `$MDV_CODE_THEME` are understood, e.g. `export
MDV_THEME=729.8953` in your .bashrc will give you a consistent color scheme.
Regarding the strange theme ids: Those numbers are the calculated total luminocity of the 5 theme colors.
mdv is designed to be used well from other (Py2) programs when they have md at hand which should be displayed to the user:
import mdv
# config like this:
mdv.term_columns = 60
# calling like this (all CLI options supported, check def main
formatted = mdv.main(my_raw_markdown, c_theme=...)
Note that I set the defaultencoding to utf-8 in
__main__. I have this as my default python2 setup and did not test inline usage w/o. Check this for risks.
Armin Ronacher's click is a great framework for writing larger CLI apps - but its help texts are a bit boring, intended to be customized.
Here is how:
Write a normal click module with a function but w/o a doc string as shown:
@pass_context
def cli(ctx, action, name, host, port, user, msg):
""" docu from module __doc__ """
On module level you provide markdown for it, like:
~/axc/plugins/zodb_sub $ cat zodb.py | head
"""
# Fetch and push ZODB trees
## ACTION: < info | pull | push | merge | dump | serve>
- info: Requests server availability information
(...)
which you set at click module import time:
mod.cli.help = mod.__doc__
Lastly do this in your app module:
from click.formatting import HelpFormatter
def write_text(self, text):
""" since for markdown pretty out on cli I found no good tool
so I built my own """
# poor man's md detection:
if not text.strip().startswith('#'):
return orig_write_text(self, text)
from axc.markdown.mdv import main as mdv
self.buffer.append(mdv(md=text, theme=os.environ['AXC_THEME']))
HelpFormatter.orig_write_text = HelpFormatter.write_text
HelpFormatter.write_text = write_text
The output has then colors:
and at smaller terms rewraps nicely:
Further, having markdown in the module __doc__ makes it simple to add into a global project docu framework, like mkdocs.
You can supply all CLI args in $HOME/.mdv, in yaml format.
More flex you have via $HOME/.mdv.py, which is execed if present, when
running main.
Alternatively, in mdv.py you can change some config straight forward.
# ---------------------------------------------------------------------- Config
txt_block_cut, code_pref, list_pref, br_ends = '✂', '| ', '- ', '◈'
# ansi cols (default):
# R: Red (warnings), L: low visi, BG: background, BGL: background light, C=code
# H1 - H5 = the theme, the numbers are the ansi color codes:
H1, H2, H3, H4, H5, R, L, BG, BGL, T, TL, C = \
231, 153, 117, 109, 65, 124, 59, 16, 188, 188, 59, 102
# Code (C is fallback if we have no lexer). Default: Same theme:
CH1, CH2, CH3, CH4, CH5 = H1, H2, H3, H4, H5
code_hl = { "Keyword" : 'CH3', "Name" : 'CH1',
"Comment" : 'L', "String": 'CH4',
"Error" : 'R', "Number": 'CH4',
"Operator": 'CH5',
"Generic" : 'CH2'
}
admons = {'note' : 'H3', 'warning': 'R',
'attention': 'H1', 'hint' : 'H4',
'summary' : 'H1', 'hint' : 'H4',
'question' : 'H5', 'danger' : 'R',
'caution' : 'H2'
}
def_lexer = 'python'
guess_lexer = True
# also global. but not in use, BG handling can get pretty involved...
background = BG
# normal text color:
color = T
show_links = None
# could be given, otherwise read from ansi_tables.json:
themes = {}
# sample for the theme roller feature:
md_sample = ''
# ------------------------------------------------------------------ End Config
Any importing module can overwrite those module global variables as well.
Should you need yet additional themes, add them to ansi_tables.json file by adding your ansi codes there.
Random results, using the theme roller feature:
Note the table block splitting when the table does not fit (last picture).
Rendering this readme 100 times:
black root@ip-10-34-2-19:~/terminal_markdown_viewer/mdv/misc# python perfest.py
0.03 paka
0.04 paka_breaks
0.04 paka_xml
1.47 mistletoe
8.70 markdown
5.22 commonmark
markdown did better than commonmark w/o extensions but table and fenced code are definitelly required for 99% users.
paka is a wrapper around the C reference lib -> requires compilation.
mistletoe is pure python, crazy that they are so much faster than CommonMark. They say in pypy they are speed up even much more.
mistletoe downside: py2 only via a fork.
pygments (using their lexer)
and, naturally, the python markdown project
Update: Next version will be CommonMark based though...
Sort of an excuse for the long long time w/o an update: I did actually start working on a more solid version based on CommonMark but that went a bit out of scope, into a general html terminal viewer, which will probably never be finished :-/
So at least here an update containing the stuff you guys sent as PRs, thanks all!!
echo -e "# foo\n## bar" | mdv - and a 'light' theme (thanks
Stanislav)Also:
-C <mode>)textwrap now for the wrapping, to avoid these word breaks a few complained about-X javascript [-x]travis
Inline link tables
"b'foo'" instead raising or auto-decoding (since you work anyway only with your UTF8-everywhere-assumption)!?-n 2-4 or -n 1-)
FAQs
Terminal Markdown Viewer
We found that mdv demonstrated a healthy version release cadence and project activity because the last version was released less than a year ago. It has 1 open source maintainer collaborating on the project.
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