.bp 
.au "TSC \- intro.xx"

.c
The lst Program

.2
How many times have you wanted the 
.T \-R 
flag on 
\f(BIls\fB to work differently in conjunction with 
.T \-t 
so that it sorts across all files, not just in each 
directory?  The \f(BIlst\fB program does this for you.
.2
This program uses several of the more common and useful Perl libraries:
.T find.pl ,
.T ctime.pl ,
.T getopts.pl ,
and
.T stat.pl .
.2
You may sort (or reverse sort) on any of the three times or the sizes.
This is a good demo of building up a table of data and then doing
a sort of that table not on the keys (names) but the values (times).
.2
The 
.T find.pl
library takes care of the complex recursive decent.  All we have
to do is define a good 
.T wanted
function.