In short :
hl is a binary program compiled from C and lex source which can greatly help you read log files, the output of commands or scripts, configuration files, text files. It can highlight thresholds, colorize blocks of text delimited by markers, alternate colors when the value of an element changes (or on the contrary when it does not change), check values consistency on a line, colorize fields of text, and so on. Many configurations have been created, and you can easily create yours to suit your needs, using simple text strings or regular expressions.
Its purpose is to colorize what is important in the text you read. It has been designed to help you get straight to the point. It's fast and efficient.
There are no need to add plug-ins when you want to colorize a new syntax : you just have to define a new configuration with basic or extended regular expressions. You don't have to install the binary nor the configuration files in a system directory, you can use environment variables to specify where to fetch the files.
At the present time, hl has only been included in the ArchLinux distribution (see https://aur.archlinux.org/packages/hl-git/ ). There are no RPM nor .deb package, and if you want to use it, you'll have to compile it for your system (which is very easy) or just use the binary on this web site. hl would be more widely spread if it can be installed using dpkg, apt-get, rpm, or yum. So if you want to create such packages, you are welcome !
Another way to contribute is to share the configurations that you have created that could help other people. To do so, please add a small comment above your configuration to specify your name, the creation date of your configuration and its purpose, and add an example of the data (as a separate file : 50 lines max) that your configuration colorizes. You also can add a screenshot of the result of the colorization of your data. Those files will be located in a sub-directory of the examples directory.
In more detail :
This command is a compiled C program which can colorize text with up to 42 colors according to specified regular expressions. It can colorize patterns on a line when it finds a match, or colorize a group of lines from a start marker to an end marker, or alternate colors when the value of a match changes, or when it doesn't change. Configuration files can be placed anywhere on the file system (not only in /etc/default) as long as you initialize the environment variables. It uses regcomp() and regexec() to colorize (highlight) strings from stdin using options on the command line.
It can be used to colorize text files (such as log files, configuration files, source files, ...) or commands output.
Here are two examples of how you can colorize the output of ls using the file date, by day (with lD) :
or by week (with lW) :
These are examples, the dates of the listed files have been modified to give suitable results. The scripts lD and lW are available in the scripts directory, and you can modify them to change the colors to your taste.
Standard system commands can be colorized without having to change their syntax nor having to manually pipe their output to the hlcommand, using the hl_generic script.
If you want to colorize the output of a command, here is what you have to do :
- Define a colorization configuration having the name of the command,
- Create a hard link on hl_generic with the name of the command,
- Make sure the directory containing the new link appears before the directory containing the original command in your PATH variable,
- Use your command the way you are used to.
hl can use up to 42 colors :
Here is the first review (Colorisez vos textes avec la commande hl) about hl in a french magazine (Linux Pratique), and here is the second one (Tirez parti de la colorisation pour faciliter la lecture de vos données).
hl: version 1.106
Usage: hl [-o][-h|-H|-V|-[[%.]eiuvdDEL1234][-[rgybmcwRGYBMCWnAIsNpPx] regexp ...][--config_name ...] ]
-o : usage will be displayed on stdout (default = stderr)
-h : help
-H : help + configuration names
-V : version
-v : verbose
-u : do not bufferize output on stdout
-e : extended regular expressions
-i : ignore case
-E : print on stderr
-r : red
-g : green
-y : yellow
-b : blue
-m : magenta
-c : cyan
-w : white
-R : red (reverse video)
-G : green (reverse video)
-Y : yellow (reverse video)
-B : blue (reverse video)
-M : magenta (reverse video)
-C : cyan (reverse video)
-W : white (reverse video)
-n : never colorize
-%c : specifies the beginning of a range colorized in color 'c'
-. : specifies the end of the previous range
-d : debug
-D : display regular expressions
-L : lex debug
-1 : color brightness (half-bright)
-2 : color brightness (normal : default)
-3 : color brightness (bright)
-4 : color brightness (underscore)
-A : alternate colors when string matched by selection regex changes
-I : alternate colors when string matched by selection regex does not change
Syntax for alternate options : -{A|I}[[s],c1c2...cn]
where s is a number from 0 to 9 indicating the selection regexp number,
and c1, c2, ... cn are color specifiers to use
Alternate colors implies extended regular expressions (-e)
-s : alternate colors when the string matched by the selection regex is the image
by a simple function (+, -, * or /) of the value of the previous matching string
Syntax for sequential control option : -s[[-+*/]p[adox]:][n],c1c2...cn]
where p is a positive integer (parameter),
n is a number from 0 to 9 indicating the selection regexp number,
and c1, c2, ... cn are color specifiers to use
d : decimal (default)
o : octal
x : hexadecimal
a : ascii (first character of the matching string)
Alternate colors implies extended regular expressions (-e)
-N : consistent numbering of sub-expressions in -A/-I and -s
-p : display configuration(s) matching glob-like expression (pattern)
-P : display configuration(s) matching regexp
-x : display options count for each config (with -vH options)
Environment variable HL_DEFAULT is undefined. Default value = "3Y".
Environment variable HL_A1 is undefined. Default value = "2B".
Environment variable HL_A2 is undefined. Default value = "1n".
Environment variable HL_CONF = "/home/machine/mb/.hl.cfg:/DATA3/projets/hl/config_files:/home/machine/mb/hl_conf"
Environment variable HL_CONF_GLOB is undefined. Default value = "hl_*.cfg:hl.cfg:.hl_*.cfg:.hl.cfg".
To use a colorized version of the "man" command, you should define a pager : MANPAGER=/usr/local/bin/hl_man_pager (and copy hl_man pager to /usr/local/bin).
# /sbin/ifconfig -a | hl -ei -m '^(eth|(vir)?br|vnet)[0-9.]*:[0-9]+\>' \
-b '^(eth|(vir)?br|vnet)[0-9.]*\.[0-9]+\>' \
-c '([0-9a-f]{2}:){5}[0-9a-f]{2}' \
-g '\<UP\>|\<RUNNING\>|([0-9]{1,3}\.){3}[0-9]{1,3}\>' \
-y '^(eth|(vir)?br|vnet)[0-9.:]*\>'
# /sbin/ifconfig -a | hl --ifconfig
# /sbin/ifconfig -a | hl --IP --MAC --eth
$ cat firewall_rules | hl -e -c INPUT \
-y 'FORWARD|POSTROUTING' \
-b '#.*' \
-W 'OUTPUT' \
-g '.*ACCEPT.*' \
-r '.*(DROP|REJECT).*' \
-m 'iptables.*-F.*' \
-w '^iptables .*'
$ cat firewall_rules | hl --iptables
$ df -h | hl --df
$ hl -p df
$ hl -ovp ifconfig
# fdisk -l | hl --fdisk
Alternate colors on the first 15 lines of vmstat :
# vmstat 1 | head -n 15 | hl -A,2B3w
Alternate colors when the first character of the filenames changes :
/bin/ls -l | hl -A1,3c2B '^[-d].*[ ](([^ ])([^ ]*))$'
or in another way using many colors :
/bin/ls -l | hl -A1,2Y3c2B2r2G '(^[-d].*[ ](.).*)$'
