crawler2.scala
changeset 92 e85600529ca5
parent 91 47f86885d481
child 93 4794759139ea
--- a/crawler2.scala	Sun Dec 23 00:38:56 2012 +0000
+++ /dev/null	Thu Jan 01 00:00:00 1970 +0000
@@ -1,44 +0,0 @@
-import io.Source
-import scala.util.matching.Regex
-
-// gets the first ~10K of a page
-def get_page(url: String) : String = { 
-  try {
-    Source.fromURL(url).take(10000).mkString  
-  }
-  catch {
-    case e => {
-      println("  Problem with: " + url)
-      ""
-    }
-  }
-}
-
-// staring URL for the crawler
-val startURL = """http://www.inf.kcl.ac.uk/staff/urbanc/"""
-
-// regex for URLs
-val http_pattern = """\"https?://[^\"]*\"""".r
-val my_urls = """urbanc""".r
-
-def unquote(s: String) = s.drop(1).dropRight(1)
-
-def get_all_URLs(page: String) : Set[String] = {
-  (http_pattern.findAllIn(page)).map { unquote(_) }.toSet
-}
-
-// naive version - seraches until a given depth
-// visits pages potentially more than once
-def crawl(url: String, n: Int) : Unit = {
-  if (n == 0) ()
-  else if (my_urls.findFirstIn(url) == None) ()
-  else {
-    println("Visiting: " + n + " " + url)
-    for (u <- get_all_URLs(get_page(url))) crawl(u, n - 1)
-  }
-}
-
-// can now deal with depth 3
-// start on command line
-crawl(startURL, 4)
-