hhighlighter (or just h)

A tiny utility to highlight multiple keywords with different colors

• Idea: Paolo Antinori

• Based on: ack - http://beyondgrep.com/ written by Andy Lester

Description

h (hhighlighter is just a name to help search engines) is a really tiny helper script meant to highlight keywords in the output of another *nix command:

Requirements

h is just a tiny facade in front of ack so you need to install it first.

What is ack?

ack is a tool like grep, optimized for programmers

Designed for programmers with large heterogeneous trees of source code, ack is written purely in portable Perl 5 and takes advantage of the power of Perl’s regular expressions.

see: http://beyondgrep.com/

ack installation

ack is part of many major linux distributions so you should use your package manager to install it.

see: http://beyondgrep.com/install/

If you want to install ack in a portable way ( at the end ack is just a script ) you do it in this way:

curl http://beyondgrep.com/ack-2.08-single-file > ~/bin/ack && chmod 0755 !#:3

Installation Instructions

h is implemented as a function in bash.

You can install it in one of these ways:

• copy and paste h() function in your ~/.bashrc

• configure your ~/.bashrc to load the external script with . /path/to/h.sh

Platform Specifics

h has currently been tested only on bash and zsh on Linux and MacOSX.

Usage

h is meant to consume the output of another Linux command via pipe

$ h
usage: YOUR_COMMAND | h [-i] [-d] args...
	-i : ignore case
	-d : disable regexp
	-n : invert colors

Configuration

h supports overriding of its default colors via 2 environment variables: H_COLORS_FG and H_COLORS_BG.

These variables accepts a comma separated values set of Perl Term::ANSIColor configuration entries. For a table of RGB colors definition check this handy map:

Figure 1: RGB Map, taken from https://github.com/jbnicolai/ansi-256-colors

Ex.

export H_COLORS_FG="bold black on_rgb520","bold red on_rgb025"
export H_COLORS_BG="underline bold rgb520","underline bold rgb025"
echo abcdefghi | h   a b c d

Examples

Default colors

echo "abcdefghijklmnopqrstuvxywz" | h   a b c d e f g h i j k l

Invert colors

echo "abcdefghijklmnopqrstuvxywz" | h -n   a b c d e f g h i j k l

Support for tail in follow mode

tail -F | h keyword1 keyword2

Case Insensitive

mvn clean install | h -i failure success

Disable regular expression

tail -F my.log | h -d org.apache.camel

Highlight multiple keys with the same color (using regexp syntax)

echo abcd | h 'b|d'

Screenshots

Demos

Ascii Cinema GifAscii Cinema Gif

Ascii Cinema: Ascii Cinema