whats command for search including sub directory ?

What is the command for search the program name from the entire directory (all directories in the unix box, means including sub directories...)

what i do is:
ls -R > allfiles
it stores all filenames in directory wise in a file; named allfiles.
then
grep myfile from allfiles.
this is the fastest way that i know if you have to search for files often.

Try find command
eg.
find / -print |grep -i programname
or
find / -type f -name programname

man find to get more option...

-timontt