.. image:: https://badge.fury.io/py/grec.png
.. image:: https://travis-ci.org/brisad/grec.png?branch=master
.. image:: https://pypip.in/d/grec/badge.png
Colorize terminal text with regular expressions.
* Free software: GPL version 3
* Documentation: https://grec.readthedocs.org.
`grec` is similar to `grep`; the difference being that instead of
printing matching lines in a file, `grec` colorizes lines. Lines that
do not match any pattern are still printed, but without color.
The key feature that separates this utility from other similar ones is
that it's possible to colorize a matching string several times without
letting previously matched colors mess up following regular expression
Install with `pip`::
pip install grec
Print the contents of `log_file.txt` in its entirety but also colorize
any occurrences of errors and warnings::
grec -m ERROR red -m WARN yellow log_file.txt
Or use a pipe::
cat log_file.txt | grec -m ERROR red -m WARN yellow -
To colorize strings in Python code, use the `Matcher` class from the
>>> from grec import Matcher
>>> m = Matcher()
>>> m.add_pattern('ERROR', 'red')
>>> m.add_pattern('WARN', 'yellow')
>>> print m.match('ERROR WARN INFO')
ERROR WARN INFO (with color)
The command line interface is the following::
grec [-m PATTERN COLOR_INFO] [-g PATTERN [COLOR_INFO ...]] -- file
The `-m` argument
This argument takes a regular expression and color information.
Here's an example that will make all lines starting with the character
"#" have a green color with white background::
-m '^#.*' green_on_white
Whenever a line matches the regular expression, the part of the line
that matched is colorized with the color information. Any number of
`-m` arguments can be specified, and colorization will be applied in
the order specified on the command line.
The regular expression will be matched by the `re` module. So for
each regular expression, only non-overlapping matches will be
colorized. To get overlapping matches use several patterns by adding
more `-m` arguments.
Color information consists of a foreground and optionally a
background. Colorization is performed with the `termcolor` package
and thus the following colors are supported: *grey*, *red*, *green*,
*yellow*, *blue*, *magenta*, *cyan*, *white*.
To only set the foreground color, simply specify the name of the
color. To also set a background color, add it to the foreground
color. Use quotes or underlines to prevent the shell from
interpreting it as several arguments. Examples::
-m <regex> blue_on_yellow
-m <regex> blue_yellow
-m <regex> 'blue on yellow'
-m <regex> 'blue yellow'
The `-g` argument
This argument is similar to `-m` but with the difference that instead
of colorizing the whole match, this creates a group pattern that only
colorizes matched groups of the regular expression.
Because one can have multiple groups within a regular expression, this
argument accepts multiple colors. Here's an example which will
colorize the first group with green color on white background and the
second with yellow foreground::
-g '^(#)(.*)' green_on_white yellow
If more colors than there are groups in the regular expression are
specified, they will be ignored. If the number of colors is less than
the groups, the last color specified for the pattern will be used to
colorize all of the remaining group matches.
The file argument
This is the file to colorize. If "-" is specified, `stdin` will be
read instead and can be used to colorize the output of a pipe.
If no file is given, `stdin` will be used as the default.
* Add support for attributes like blinking
* Add support for only changing background color from CLI
* Python 3 support
* Added support for colorizing groups in regular expressions
* First release on PyPI.
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