searching a file with a specified text without using conventional file searching commands

without using conventional file searching commands like find etc, is it possible to locate a file if i just know that the file that i'm searching for contains a particular text like "Hello world" or something?

 
find . -type f | xargs grep -il "hello world"

without using find .. or for that matter without using conventional file searching commands

Try this strawman and expand as required...

#!/bin/sh
for i in `ls -R`
do
   cat $i | grep "Hello World"
done

Note this only return the string. If you want to include the filename as well, then echo $i somewhere...

A question like "without using ...." smells of homework, if not 100%, its almost 99%.. Any reason why you cannot use find?

grep, egrep, fgrep - print lines matching a pattern, so not a find-like utility.

grep "Hello World" -iR