Start background process from shellscript then bring back to foreground later - shell

Question

I'm trying to make a shell script that does the following:
Start program x
While x is running execute some commands, for example:
echo "blabla" >> ~/blabla.txt
After the execution of those commands program x should be running in the foreground, so that it can take user input.
So far I have:
~/x &
echo "blabla" >> ~/blabla.txt
However, I don't know how to move x back to the foreground. This is all called from a shell script so I don't know the job number of x to move to the foreground.
Note: everything has to be automated, no user interaction with the shell script should be needed.
Any suggestions are welcome :)

Answer 1

Although absolutely don't understand why someone may need such script, and I'm sure than exists more elegant and more better/correct solution - but ok - the next demostrating how:
The script what going to background (named as bgg)
#!/bin/bash
for i in $(seq 10)
do
echo "bg: $i"
sleep 1
done
read -p 'BGG enter something:' -r data
echo "$0 got: $data"
the main script (main.sh)
set -m #this is important
echo "Sending script bgg to background - will cycle 10 secs"
./bgg & 2>/dev/null
echo "Some commands"
date
read -r -p 'main.sh - enter something:' fgdata
echo "Main.sh got: ==$fgdata=="
jnum=$(jobs -l | grep " $! " | sed 's/\[\(.*\)\].*/\1/')
echo "Backgroung job number: $jnum"
echo "Now sleeping 3 sec"
sleep 3
echo "Bringing $jnum to foreground - wait until the BG job will read"
fg $jnum
run the ./main.sh - and the result will be something like
Sending bgg to background - will cycle 10 secs
Some commands
Mon Mar 3 00:04:57 CET 2014
main.sh - enter something:bg: 1
bg: 2
bg: 3
bg: 4
bg: 5
qqbg: 6
qqqqq
Main.sh got: ==qqqqqqq==
Backgroung job number: 1
Now sleeping 3 sec
bg: 7
bg: 8
bg: 9
Bringing 1 to foreground - wait until the BG job will read
./bgg
bg: 10
BGG enter something:wwwwwww
./bgg got: wwwwwww

Answer 2

You can use fg to bring the last background process to foreground