Highlight

highlight
is a command line program for highlighting parts of a file matching
a regex.
For example, take a look at the following file:

highlight
can be used to highlight the regex cat
:

Uses
This package installs two binaries, highlight
and hrep
. The following
section explains the main uses of highlight
and hrep
.
highlight
highlight
is used to highlight a given regex in a file, while printing out
all lines of the file.
The short example above show how to use highlight
to highlight a regex in a
single file. It is also possible to use highlight
on multiple files at once:

highlight
will color and stripe the filenames to make it easier to see which
line came from which file. This also shows an example of the --ignore-case
option, which is similar to grep
’s --ignore-case
option.
highlight output from grep
highlight
has a special option for highlighting output from grep
:

This --from-grep
option will color and stripe filenames, similar to the
previous example.
hrep
With the previous --from-grep
option to highlight
, one unfortunate point is
that the regex has to be specified twice, once to grep
and once to
highlight
.
The hrep
command can solve this for us. It is just like the grep
command,
but it will color and stripe filenames:

Installation
highlight
and hrep
can be installed with
stack
:
$ stack install highlight
It should also be possible to use cabal
to install this package.
Other ways to highlight parts of files
It is possible to highlight lines matching a given regex with grep
two
different ways.
-
Use a special regex that will match any line, but only highlight the part
desired. It would look like this:
$ grep 'about|$' file-cats file-dogs file-goats
-
Give a large --context
flag:
$ grep --context 9999 'about' file-cats file-dogs file-goats
However, neither of these will color and stripe filenames.
Contributions
Feel free to open an
issue or
PR for any
bugs/problems/suggestions/improvements.
Additional flags
highlight
and hrep
do not currently support all flags and options that
grep
does. Ideally, highlight
and hrep
would be drop-in replacements for
grep
, supporting all the same flags and options as grep
.
If there is a flag or option you frequently use and want supported with
highlight
or hrep
, please feel free to open an issue or PR. Some
flags/options will be relatively easy to support, while some may require quite
a large amount of additional code.