Emergency UNIX and Linux Support

sed 's|"http://[^"]*"|&\n|g' infile | sed -n 's|.*\("http://[^"]*"\).*|\1|p'

pat='"http://[^"]*"'
sed "s|$pat|&\n|g" infile | sed -n "s|.*\($pat\).*|\1|p"

perl -nle'print$1while m|("http://[^"]*")|g' infile

bash-3.00$ echo '"http://a.b.c" blablabla "http://b.b.f"' | sed 's|\"http://[^\"]*\"|&\n|' | sed -n 's|.*\("http://[^"]*"\).*|\1|p'

o/p
"http://b.b.f"

nawk -F\" '{ 
  for (i=0; ++i<=NF;)
    if ($i ~ /^http:\/\//) print FS $i FS
  }' infile

nawk  '/^http:/&&$0=RS$0RS' RS=\" infile