root@quivira-backup:~# cat testrep 
p0p0p0p0p0
p98B456021
aaa
aa
aaaa
ppppppppp
pppp
p
pppppp
CCCC
BB
DDD
root@quivira-backup:~# cat testrep |grep '[a-zA-Z]*[p][a-zA-Z]*[p][a-zA-Z]*[p][a-zA-Z]*\s'
root@quivira-backup:~#