pkg://jed-0.99.18-7.fc9.i386.rpm:962719/usr/share/doc/jed-0.99.18/doc/txt/rgrep.txt  info  downloads

This file documents rgrep, a recursive, highlighting grep program.

Currently, rgrep is only available on Unix systems.  To build it, move to
the src directory for JED and enter: `make rgrep'.

Why use rgrep instead of more traditional Unix tools?
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Unlike grep and egrep, rgrep has the ability to recursively descend
directories. The traditional way of performing this kind of search on Unix
systems utilizes the `find' command in conjunction with `grep'.  However,
this results in very poor performance.  Consider the tradional approach
where one wants to search the /usr/include directory for the string `FD_SET':
For this, one would use:

% find /usr/include -exec grep -l FD_SET \{\} \; -print

Ignoring the fact that the above expression looks complex, it failed to find
any occurence of FD_SET under the /usr/include directory of my Ultrix
system.  

Now, if rgrep is used, one types:

% rgrep -lFr FD_SET /usr/include

which yielded: /usr/include/sys/types.h

The reason that `find' failed is that /usr/include/sys is a symbolic link to
/sys/h.  `rgrep' was able to succeed because of the `-F' flag which telles
it to follow links.  I looked in the man page for a similar option for
`find' but nothing turned up.