# HG changeset patch # User Christian Urban # Date 1380188363 -3600 # Node ID 4758a615587825b80eb687c65c9ec20ffe4b0a2b # Parent cbc2270c2938232805f05aa77cd0bdccc8ce4eca links diff -r cbc2270c2938 -r 4758a6155878 progs/crawler1.scala --- a/progs/crawler1.scala Thu Sep 26 10:36:24 2013 +0100 +++ b/progs/crawler1.scala Thu Sep 26 10:39:23 2013 +0100 @@ -1,8 +1,11 @@ +// A crawler which checks whether there +// are problems with links in web-pages + import io.Source import scala.util.matching.Regex import scala.util._ -// gets the first ~10K of a page +// gets the first ~10K of a web-page def get_page(url: String) : String = { Try(Source.fromURL(url).take(10000).mkString) getOrElse { println(s" Problem with: $url"); ""} @@ -11,6 +14,7 @@ // regex for URLs val http_pattern = """\"https?://[^\"]*\"""".r +// drops the first and last character from a string def unquote(s: String) = s.drop(1).dropRight(1) def get_all_URLs(page: String) : Set[String] = { @@ -32,7 +36,5 @@ //val startURL = """http://www.inf.kcl.ac.uk/staff/mml/""" -// call on the command line crawl(startURL, 2) -crawl("""http://www.inf.kcl.ac.uk/staff/urbanc/bsc-projects-13.html""", 2) diff -r cbc2270c2938 -r 4758a6155878 progs/crawler2.scala --- a/progs/crawler2.scala Thu Sep 26 10:36:24 2013 +0100 +++ b/progs/crawler2.scala Thu Sep 26 10:39:23 2013 +0100 @@ -5,7 +5,7 @@ import scala.util.matching.Regex import scala.util._ -// gets the first ~10K of a page +// gets the first ~10K of a web-page def get_page(url: String) : String = { Try(Source.fromURL(url).take(10000).mkString) getOrElse { println(s" Problem with: $url"); ""} @@ -28,7 +28,7 @@ // visits pages potentially more than once def crawl(url: String, n: Int) : Unit = { if (n == 0) () - //else if (my_urls.findFirstIn(url) == None) () + else if (my_urls.findFirstIn(url) == None) () else { println(s"Visiting: $n $url") for (u <- get_all_URLs(get_page(url))) crawl(u, n - 1) diff -r cbc2270c2938 -r 4758a6155878 progs/crawler3.scala --- a/progs/crawler3.scala Thu Sep 26 10:36:24 2013 +0100 +++ b/progs/crawler3.scala Thu Sep 26 10:39:23 2013 +0100 @@ -5,7 +5,7 @@ import scala.util.matching.Regex import scala.util._ -// gets the first ~10K of a page +// gets the first ~10K of a web-page def get_page(url: String) : String = { Try(Source.fromURL(url).take(10000).mkString) getOrElse { println(s" Problem with: $url"); ""}