Instant search in less command? (Similar to incsearch in VIM)

Question

Is there a way to search, while I'm typing in less? Just like the vim option, set incsearch.

As I didn't find a proper way to do it, is there any similar tool that can do it?

Answer 1

You can do a search from the command line:

less -ppattern filename

Or, once inside less, use / followed by your pattern to do interactive searching (forwards). n and N repeat the search in the forward and reverse direction, respectively. That's the bare minimum you need to know; there are many more commands for more complex or specific searches.

Edit: To respond to your updated question, there's currently no way to do immediate incremental searching with less. Have you considered using view instead (opens Vim in read-only mode, so will use your incsearch setting)? Vim can be made even more pager-like with the vimpager script.

Some additional information: There is an open bug on the Ubuntu bug-tracker for incremental search support, but it doesn't look like it's going anywhere soon. Somebody has implemented incremental support on a github fork, but obviously you're going to have to compile a custom less to use that.

(And apart from the Ubuntu enhancement request there is currently (as of 2016-05-17) no such enhancement request on the official less bugtracker.)

Answer 2

It was implemented in https://github.com/gwsw/less/commit/b09a0c452d08afe2da8c9632d4fa768d6474b371 2 months ago, and hopefully will be coming to a distro near us!

Answer 3

less --incsearch filename

Added in this commit on January 13 2021.

Answer 4

http://greenwoodsoftware.com/less/

Version 598 was released for beta testing on 7 December 2021.

I add --incsearch to my LESS environment variable:

export LESS='--incsearch  --ignore-case --status-column --LONG-PROMPT --RAW-CONTROL-CHARS --HILITE-UNREAD --tabs=4 --no-init --window=2 '
    # Man-db passes extra options to the pager via the `LESS` environment variable,
    # which Less interprets in the same way as command line options.
    # The setting is hard-coded at compile time and starts with -i.
    # (The value is "-ix8RmPm%s$PM%s$" as of Man-db 2.6.2; the P…$ part is the prompt string.)


    # "--RAW-CONTROL-CHARS":   Get color support for 'less'
    # --no-init: This is sometimes  desirable if the deinitialization string does something unnecessary, like clearing the screen
    # --HILITE-UNREAD:  highlight first unread line after forward movement

    # https://www.topbug.net/blog/2016/09/27/make-gnu-less-more-powerful/
source $HOME/dot_file/color_less_wf.zsh

These are the differences between version 590 and version 598:

Add the --header option.
Add the --no-number-headers option.
Add the --status-line option.
Add the --redraw-on-quit option.
Add the --search-options option.
Add 'H' color type to set color of header lines.
Add #version conditional to lesskey.
Add += syntax to variable section in lesskey files.
Allow option name in -- command to end with '=' in addition to '\n'.
Add $HOME/.config to possible locations of lesskey file.
Add $XDG_STATE_HOME and $HOME/.local/state to possible locations of history file.
Don't read or write history file in secure mode.
Fix display of multibyte and double-width chars in prompt.
Fix ESC-BACKSPACE command when BACKSPACE key does not send 0x08.
Add more \k codes to lesskey format.
Fix bug when empty file is modified while viewing it.
Fix bug when parsing a malformed lesskey file.
Fix bug scrolling history when --incsearch is set.
Fix buffer overflow when invoking lessecho with more than 63 -m/-n options.
Fix display bugs with --header.
Fix bug restoring color at end of highlighted text.
Fix bug in parsing lesskey file.