grep: a pedestrian, very fast grep utility

a fast grep utility, which finds string pattern(s) in all or selected files of any type in a folder and its subfolders (if the recursion flag -r is set).

file access and string matching are optimized by low-level i/o and string routines.
the recursion algorithm (-r) does not use ML's genpath.

the syntax and options as well as the output closely follow its unix/linux sibling.
string patterns may be defined as regular expressions.

many options allow to fine tune the GREP engine including an extensive set of inclusion/exclusion flags for folders, files, and full paths, which implement a regular expression based wildcard search.

clicking on an underlined text item will open the file at the matching line.

several help levels are implemented

1) quick overview
> grep
> help grep
sparse information about syntax and option flags (see screenshot)

2) extended help
> grep -p
syntax/peculiarities of pattern/file arguments
> grep -e
several examples (see also grepdemo.m)
> grep -f
for programmers: explanation of the second output argument

see the accompanying published M file for instructions and a few typical examples.