remark Command: Highlight Any Text or Command Output Using Regular Expressions

The remark command is a little know tool that can be used to color syslog file as well as output of of programs such as ping, traceroute, and much more.

You can highlight text using regular expressions and specific rule formats. The hierarchical rules-format is simple to understand, yet very powerful. The remark will read each line from stdin and each line is highlighted according to rules defined in FILE, and is then printed to stdout (screen).

Install remark

Type the following command under Debian / Ubuntu Linux to install regex-markup:
$ cd /tmp
$ wget http://savannah.nongnu.org/download/regex-markup/regex-markup_0.10.0-1_amd64.deb
$ sudo dpkg -i regex-markup_0.10.0-1_amd64.deb
If you are using RHEL / CentOS / Fedora Linux 64bit, type the following command to install regex-markup:
$ cd /tmp
$ wget http://savannah.nongnu.org/download/regex-markup/regex-markup-0.10.0-1.x86_64.rpm
$ rpm -ivh regex-markup-0.10.0-1.x86_64.rpm
Or you can compile and install it using source code:
$ cd /tmp
$ wget http://savannah.nongnu.org/download/regex-markup/regex-markup-0.10.0.tar.gz
$ tar -xvf regex-markup-0.10.0.tar.gz
$ cd regex-markup-0.10.
$ ./configure
$ make
$ sudo make install

Syntax

The syntax is:

 
command1 | remark /path/to/config
command2 arg1 arg2 | remark /path/to/config
 

Examples

Highlight ping output using the ping rules file:
$ ping -c 4 nixcraft.com | remark /usr/share/regex-markup/ping
Sample outputs:

Fig.01: ping command in action

 
ping() { /bin/ping $@ | remark /usr/share/regex-markup/ping; }
 

More about /usr/share/regex-markup/ping

The /usr/share/regex-markup/ping is a rule file for ping command. It consists of style and macro definitions, and match statements. Order of match statements is important, since they are executed from top down. Styles and macros need to be defined before they are used. The syntax of rule files is similar to that of programming languages such as C and Java in that indentation and use of whitespace doesn't matter.:
$ cat /usr/share/regex-markup/ping
Sample outputs:

 
# Rules to highlight the output of ping(8)
 
include "common"
 
# Special: Color all lines that don't match any of the rules below red
/.*/ red
 
 
/^PING ([-.a-zA-Z0-9]+) \(([-.a-zA-Z0-9]+)\) ([0-9]+)\(([0-9]+)\) bytes of data\.$/ {
  default
  1 blue
  2 green
  3,4 red
  break		# this is merely to skip the matches below
}
 
/^PING ([-.a-zA-Z0-9]+) \(([-.a-zA-Z0-9]+)\): ([0-9]+) data bytes$/ {
  default
  1 blue
  2 green
  3 red
  break		# this is merely to skip the matches below
}
 
/^([0-9]+) bytes from ([-.a-zA-Z0-9]+) \(([-.a-zA-Z0-9]+)\): icmp_seq=([0-9]+) ttl=([0-9]+) time=(.*)$/ {
  default
  1,4,5,6 red
  2 blue
  3 green
  break
}
/^([0-9]+) bytes from ([-.a-zA-Z0-9]+): icmp_seq=([0-9]+) ttl=([0-9]+) time=(.*)$/ {
  default
  1,3,4,5 red
  2 green
  break
}
 
/^--- ([-.a-zA-Z0-9]+) ping statistics ---$/ {
  default
  1 blue
  break
}
 
/^([0-9]+) packets transmitted, ([0-9]+) packets received, ([0-9]+)% packet loss$/ {
  default
  1,2,3 red
  break
}
/^([0-9]+) packets transmitted, ([0-9]+) received, ([0-9]+)% packet loss, time ([0-9]+ms)$/ {
  default
  1,2,3,4 red
  break
}
 
/^round-trip min\/avg\/max = ([.0-9]+)\/([.0-9]+)\/(.*)$/ {
  default
  1,2,3 red
  break
}
/^rtt min\/avg\/max\/mdev = ([.0-9]+)\/([.0-9]+)\/([.0-9]+)\/(.*)$/ {
  default
  1,2,3,4 red
  break
}
 

The default style is defined in /usr/share/regex-markup/common file:
$ cat /usr/share/regex-markup/common
Sample outputs:

 
# Some styles for ANSI character attributes
 
style plain     { pre "\E[0m"  post "\E[0m"  }
 
style bold      { pre "\E[1m"  post "\E[22m" }
style underline { pre "\E[4m"  post "\E[24m" }
style blink     { pre "\E[5m"  post "\E[25m" }
style inverse   { pre "\E[7m"  post "\E[27m" }
 
style black     { pre "\E[30m" post "\E[39m" }
style red       { pre "\E[31m" post "\E[39m" }
style green     { pre "\E[32m" post "\E[39m" }
style yellow    { pre "\E[33m" post "\E[39m" }
style blue      { pre "\E[34m" post "\E[39m" }
style magenta   { pre "\E[35m" post "\E[39m" }
style cyan      { pre "\E[36m" post "\E[39m" }
style white     { pre "\E[37m" post "\E[39m" }
 
style blackbg   { pre "\E[40m" post "\E[49m" }
style redbg     { pre "\E[41m" post "\E[49m" }
style greenbg   { pre "\E[42m" post "\E[49m" }
style yellowbg  { pre "\E[43m" post "\E[49m" }
style bluebg    { pre "\E[44m" post "\E[49m" }
style magentabg { pre "\E[45m" post "\E[49m" }
style cyanbg    { pre "\E[46m" post "\E[49m" }
style whitebg   { pre "\E[47m" post "\E[49m" }
 
style standard   { pre "\E[38m" post "\E[39m" }         # XXX
style standardbg { pre "\E[48m" post "\E[49m" }         # XXX
style default    { pre "\E[39m" post "\E[39m" }         # XXX
style defaultbg  { pre "\E[49m" post "\E[49m" }         # XXX
 

Type the following command:
$ traceroute www.cyberciti.biz | remark /usr/local/share/regex-markup/traceroute
Sample outputs:

Fig.02: traceroute in action

Highlight Linux server syslogs entries

Type the following command:

 
grep something /var/log/syslog | remark /usr/share/regex-markup/syslog
tail -f  /var/log/syslog | remark /usr/share/regex-markup/syslog
 

Highlight diff command output

Type the following command:

 
diff file1 file2 | remark /usr/share/regex-markup/diff
 

Highlight make command output

Type the following command:

 
cd /path/to/build
make | remark /usr/share/regex-markup/make
 

How do I create my own regex-markup?

You need to read remark command man page for rule format and style:
$ man remark

References:

1. regex-markup

Tagged as: Linux, Unix

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