xxxxxxxxxx
grep -rl oldtext /path/to/find/oldtext | xargs sed -i 's/oldtext/newtext/g'
xxxxxxxxxx
grep -rl "oldtext" /path/to/folder | xargs sed -i 's/oldtext/newtext/g'
xxxxxxxxxx
find /home/www \( -type d -name .git -prune \) -o -type f -print0 | xargs -0 sed -i 's/subdomainA\.example\.com/subdomainB.example.com/g'