Jumping to end/beginning of line in “less -S”

lesspager

The commonly used pager less can be started with the option -S, prevents it from breaking lines.

One can then press the right and left arrow keys to scroll horizontally.

Since the lines can be quite long, I was wondering whether there a keystroke or a way to jump to the end of the line.

I know that one can increase the step size less uses for scrolling.
The problem is, that less doesn't stop to scroll horizontally at the end of the line.
Therefore just setting a high numerical value for the step size (scrolling increment) would usually put the view beyond the end of the line.

Best Answer

From the manual:

   ESC-} or ^RIGHTARROW
          Scroll horizontally right to show the end of the longest displayed line.

   ESC-{ or ^LEFTARROW
          Scroll horizontally left back to the first column.

These escape sequences were introduced in less version 487, released on 2016-10-25.

Related Solutions

Vim – How to Scroll Large Datafile While Keeping Header

If you're familiar with vim, this is probably the best option for you. You can enable horizontal-scroll-bind-only by changing 'scrollopt':

set scrollopt=hor

So with vim -u NONE, you get the desired behavior with:

:set scrollopt=hor
:set nowrap
:1split
:windo set scrollbind

You may want to adjust 'sidescroll' and 'sidescrolloff' to change how many columns are skipped and how far from the edge skipping starts respectively.

Less Scrolling – Horizontal Scrolling in Smaller Increments with Less -S

The only horizontal scrolling commands scroll by half a screenful, but you can pass a numeric argument to specify the number of characters, e.g. typing 4 Right scrolls to the right by 4 characters. Less doesn't really have a notion of “current line” and doesn't split a line into words, so there's no way to scroll by a word at a time.

You can define a command that scrolls by a fixed number of characters. For example, if you want Shift+Left and Shift+Right to scroll by 4 characters at a time:

Determine the control sequences that your terminal sends for these key combinations. Terminals send a sequence of bytes that begin with the escape (which can be written \e, \033, ^[ in various contexts) character for function keys and keychords. Press Ctrl+V Shift+Left at a shell prompt: this inserts the escape character literally (you'll see ^[ on the screen) instead of it being processed by your shell, and inserts the rest of the escape sequence. A common setup has Shift+Left and Shift+Right send \eO2D and \eO2C respectively.
Create a file called ~/.lesskey and add the following lines (adjust if your terminal sends different escape sequences):
```
#command
\eO2D noaction 4\e(
\eO2C noaction 4\e)
\eOD noaction 40\e(
\eOC noaction 40\e)
```
In addition to defining bindings for Shift+arrow, you may want to define bindings for arrow alone, because motion commands reuse the numeric values from the last call. Adjust 40 to your customary terminal width. There doesn't appear to be a way to say “now use the terminal width again, whatever it is at this moment”. A downside of these bindings is that you lose the ability to pass a numeric argument to Left and Right (you can still pass a numeric argument to Esc ( and Esc )).

Then run lesskey, which converts the human-readable ~/.lesskey into a binary file ~/.less that less reads when it starts.

Best Answer

Related Solutions

Vim – How to Scroll Large Datafile While Keeping Header

Less Scrolling – Horizontal Scrolling in Smaller Increments with Less -S

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