#!/bin/sh
#
# Usage: lookfor <directory> <-/+days> <word> <word> ...
# lookfor - look for all files in the specified directory hierarchy
# modified within a certain time, and pass the resulting names to
# egrep to scan for a particular pattern.  

where="$1"
when="$2"
shift; shift
# Build egrep expression like (word1|word2|...) in $expr
for word
do
    case "$expr" in
    "") expr="($word" ;;
    *) expr="$expr|$word" ;;
    esac
done
expr="$expr)"

# Do the search in one sweep, passing the results of the find to egrep
find $where -mtime $when -print | xargs egrep -i "$expr" /dev/null