A Better less

I use emacs – with a server¹ and client setup – so that I can quickly open new files in it using emacsclient. My typical setup is to have xterm + tmux on one monitor and a single emacs(client) frame on another. But there are times when I do not want to shift focus from one monitor to another, like when I just need to review some log file. So I started using an alias to emacs -nw -Q to quickly open log files, review, filter, and C-x C-c.

Of course, that’s not where this post ends. An alias was no longer adequate to do what I wanted it to do more ..

I typically do my text editing in the emacs frame, while do just non-editing actions like viewing, navigating, searching, filtering in quick emacs sessions from tmux.

I wanted that “tmux emacs” to be independent of my config, independent of the server – Just something really quick that I can launch, do, and quit. I wanted something like less, but better .. better in these ways:

• Do syntax highlighting
• Render Org-mode files
• A better navigable man page viewer
• Dired, especially wdired (batch edit symbolic links, for example?)²
• Show colored diffs
• Filter log files to only show or not show lines matching a regexp
• Start auto-reverting 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:

Click the below image to see a GIF animation in larger size.

As a bonus:

• This script passes ShellCheck, and
• Unofficial Bash strict mode is enabled.

Try it out and let me know how you find it. As you will see, eless is a bash script where most of it is a string containing a sane emacs configuration for view-mode. I wanted eless to be a monolithic script, and not a multi-file setup.

eless -h | eless

Update (2017/04/25)

Thanks to the PR by Iqbal Ansari, eless now supports reading piped-in data even when emacs is run in terminal mode. The solution was to:

• Always start the emacs process in a sub-shell, and
• Redirect /dev/tty into that emacs instance.

That way, that emacs instance would always think that it is receiving input from tty – even when the wrapper bash script is receiving input from the pipe.