ref: 53712a22e4b67d805c888a08f4586067c047bf62
dir: /clear/
#!/bin/rc
# clears all the output from programs,
# leaving only the command prompts
grep `{echo -n '^'^$prompt(1)} </dev/text | \
grep -v '^'^$prompt(1)^clear | \
uniq >/tmp/clearing.$pid
cp /tmp/clearing.$pid /dev/text
rm -f /tmp/clearing.$pid