colorize

Colorize unstructured text to hightlight specific strings for an ANSI terminal

This simple little program is useful for highlighting specific items that may help debugging issues in log files.

It can be used with tools like cat and grep.

Here is how it could be used.

$ cat -n log | colorize "error:|note:|warning:"

The regular expression syntax is the regular golang regular expression syntax that is described here: https://github.com/google/re2/wiki/Syntax.

It is written go-1.10. It has been tested on Mac and Linux systems.

Usage

In the simplest case, simply run the program with a list of patterns to patch and pipe input to it as shown in the initial example.

The color of each pattern can specified independently using a color map as this simple example shows where strings in enclosed in double quotes are highlighted in green and the three keywords are highlighted in red.

$ cat -n log | colorize -c "red+bold,green" "error:|note:|warning:" '\"[^\"]*\"'

There is more information about color maps in the COLOR MAP section.

Example

$ bin/native/colorize  -i /tmp/make.log -c red+bold,green,red+bold 'error:.*$|note:.*$|warning:.*$' "'[^']*'" '^.*errors generated'

Options

Short	Long	Description
--	--	Everything after this is taken as literal.
-c COLOR_MAP	--color-map	Specify the pattern color map.
-h	--help	Print help message and exit.
-i FILE	--input FILE	Read a file. If not specified, read stdin.
-v	--verbose	Increase the level of verbosity.
-V	--version	Print the version and exit.

Color Map

The color map allows different colors to be specified for each pattern. If this option is not specified the same color is used for all patterns.

The color map allows an ANSI terminal color code to be specified. It also has some short cut names to make things easier. The short cuts are appended using a plus (+) sign for each pattern.

A simple example might make this clearer. If you have two patterns and want to color matches to the first one in green and matches to the second one in blue you would do this.

$ cat logfile | colorize -c green+bold,blue+bold 'pattern1' 'pattern2'

If the color map (-c) is not specified all matches will be in red+bold which is the default.

The raw components of the ANSI terminal code can be specified as digits. For example, -c red+bold is the same as -c 31+1. They both ultimately translate to the binary sequence: \033[31;1m.

If the number of color map entries is less than the number of patterns, the last color map entry is extended to all of the remaining patterns.

The table below presents the list of short cut options.

Ref	Name	Value	Description
1	blue	34	Foreground blue.
2	blueB	44	Background blue.
3	bold	1	Make the color bold.
4	cyan	36	Foreground cyan.
5	cyanB	46	Background cyan.
6	faint	2	Make the color faint.
7	gray	38;5;245	Foreground light gray.
8	grayB	48;5;245	Background light gray.
9	green	32	Foreground green.
10	greenB	42	Background green.
11	italic	3	Mke the text italic.
12	magenta	35	Foreground magenta.
13	magentaB	45	Backgroundmagenta.
14	normal	22	Make the next normal.
15	red	31	Foreground red.
16	redB	41	Background red.
17	reset	0	Reset.
18	reverse	7	Reverse the fore/background colors.
19	strike	9	Strike-through the text.
20	underline	4	Underline the text.
21	white	36	Foreground white.
22	whiteB	46	Background white.
23	yellow	33	Foreground yellow.
24	yellowB	43	Background yellow.

Here are some more examples of what can be done with the short cuts.

-c 'red+greenB+bold,blue+bold'

1. First pattern is bold red on a bold green background.
2. Second pattern is bold blue on the default background.

-c 'red+greenB'

1. First pattern is normal red on a normal green background.

Anlyzing a colorized buffer in emacs

Add the following code to ~/.emacs.

;; colorize ansi term sequences
(require 'ansi-color)
(defun ansi-colorize ()
  "Colorize ansi escape sequences in the current buffer."
  (interactive)
  (ansi-color-apply-on-region (point-min) (point-max)))

Write the colorized log data to a separate log.

$ make 2>&1 /tmp/log
$ colorize -i /tmp/log -c red+bold,blue+bold,green+bol 'error:|warning:' 'note:' "'[^']*'" > /tmp/logc

Bring /tmp/logc up in emacs and run the ansi-colorize function.