eless

#+title: Eless - A Better Less #+author: Kaushal Modi [[https://github.com/kaushalmodi/eless/actions][https://github.com/kaushalmodi/eless/actions/workflows/test.yml/badge.svg]]

[[https://eless.scripter.co][Documentation]]

[[https://github.com/kaushalmodi/eless][eless]] is a combination of Bash script and a minimal emacs =view-mode= config.

This script is designed to:

• Be portable -- Just one bash script to download to run
• Be independent of a user's emacs config
  • /You can still [[https://eless.scripter.co/#user-config-override][customize]] the =eless= config if you like./
• Not require an emacs server to be already running

It was created out of a need to have something /like/ =less= (in the sense of /launch quickly, do, and quit/), but /better/ in these ways:

• Syntax highlighting
• Org-mode file rendering
• A better navigable man page viewer
• A better Info viewer
• Dired, especially =wdired= (batch edit symbolic links, for
  example?)
• Colored diffs, =git diff=, =git log=, =ls=, etc. (auto ANSI
  detection)
• Filter log files to only show (or not show) lines matching a regexp
• Auto-revert log files when I want (like =tail -f=)
• Quickly change frame and font sizes
• .. and more; basically everything that emacs has to offer!

I call it =eless= and here's a little taste of what it looks like:

[[https://raw.githubusercontent.com/kaushalmodi/eless/master/docs/images/eless-examples.png][https://raw.githubusercontent.com/kaushalmodi/eless/master/docs/images/eless-examples.png]]

/Shown above, starting from top left image and proceeding clock-wise../

• =eless eless.org=
• =rg --color=ansi 'man pages' | eless= (rg[[https://github.com/BurntSushi/ripgrep][?]])
• =man grep= (I have set my =PAGER= env var to =eless=.)
• =info eless= (I have aliased =info= to ='\info !* | eless'= in my
  tcsh shell.)
• =eless .= (Shows the current directory contents in =dired=.)
• =diff= of =eless.org= with an older saved version and piping the
  result to =eless=

Meta Features

• This script passes [[https://www.shellcheck.net][ShellCheck]], and
• Unofficial Bash /strict mode/[fn:1] is enabled.
• Always-in-sync documentation as the =eless= script and
  documentation are generated using Org Babel from [[https://github.com/kaushalmodi/eless/blob/master/eless.org][one file]] (even this
  README).
• The [[https://eless.scripter.co][documentation site]] is generated on-the-fly on Netlify using
  that same /one file/.
• This bash script has tests too!

[fn:1] http://redsymbol.net/articles/unofficial-bash-strict-mode/

• Requirements
  |-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
  | Software | Details |
  |-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
  | =emacs= | If only running the =eless= script, the mininum required emacs version is 22.1 (manually tested). If developing (running =make all html test=), the minimum required version is 25.3. |
  | =bash= | This is a =bash= script. So even if you don't use =bash= shell, you need to have the =bash= binary discoverable through your environment variable =PATH=. /Tested to work in =tcsh= shell on RHEL 6.6./ |
  | =perl= | Perl is used to replace =grep -Po= and case-insensitive =sed= based replacements (using =/I=) as those features are available only in GNU versions of =grep= and =sed= (which are not present by default on /macOS/ systems). /Tested with Perl v5.16.3 on RHEL 6.6./ |
  | =texinfo= | Required to generate the eless Info manual (when doing =make install=) |
  |-----------+-----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|

• NOTE 1 :: If the environment variable =EMACS= is set, =eless= uses
  that as the emacs binary, else it defaults to using =emacs= as emacs
  binary.
• NOTE 2 :: eless is known to not work with /info (texinfo) 6.1/ (see
  =eless= issue #[[https://github.com/kaushalmodi/eless/issues/35][35]]). If you want to use eless to view Info manuals,
  ensure that it is at least version 6.5.

• Installation
  ** Manual installation
  *** Clone this rep
  For the following instructions, let's assume that you clone this repo
  to =~/downloads/eless=.
  #+begin_src shell
  git clone https://github.com/kaushalmodi/eless ~/downloads/eless
  #+end_src
  *** Run make
  #+begin_src shell
  cd /downloads/eless
  make install PREFIX=/.local
  #+end_src
  *** Installation Directory Structure
  The above make install will install the eless script and
  documentation in a directory structure like this:
  #+begin_example