mgrep is a command line tool that allows users to search text files for lines matching a given regular expression. It is similar to the well-known Unix utility, grep.
As a natural extension to the single-line regular expressions, mgrep is also capable of searching for multiline patterns.
mgrep is not a grep replacement, but it is intended to be grep-compatible: implemented options and behavior should be the same as those of grep.
mgrep is written in C++ using the Boost.Regex library.
A configure/make system is provided for Linux, but its source code should compile on all platforms that have the std and Boost.Regex libraries installed.
Great app multiline-grep