file access (open and pipe?) problem

Comments

• Souldrinker

  January 2004

  ehm... writing a webserver in perl is always a favorite I won`t describe the webserver here - only the file reading:
  
  my $FileContent = "";
  
  open ( FILEHANDLE, "<[Location of your File" );
  while ( <FILEHANDLE> )
  {
  $FileContent .= $_;
  }
  close ( FILEHANDLE );
  
  Now in "$FileContent" there is all of the content in the specified file.
  best regards,
  
  sebastian mohrenstecher
  executive secretary
  net::allies
  
  www.net-allies.de
  info@net-allies.de
  
  
• Jonathan

  January 2004

  : ehm... writing a webserver in perl is always a favorite I won`t
  : describe the webserver here - only the file reading:
  :
  : my $FileContent = "";
  :
  : open ( FILEHANDLE, "<[Location of your File" );
  : while ( <FILEHANDLE> )
  : {
  : $FileContent .= $_;
  : }
  : close ( FILEHANDLE );
  :
  : Now in "$FileContent" there is all of the content in the specified
  : file.
  I always liked:-
  open ( FILEHANDLE, "<[Location of your File" );
  my $FileContent = join('', <FILEHANDLE>);
  close ( FILEHANDLE );
  But that's just me being choosy. Better you can undef $/ and slurp the whole file. So yay, we have three ways of reading a file now.
  
  On the web server stuff, you need to look at the headers that are recieved by the server. Find one that looks like:-
  
  GET /path/to/file.htm
  
  You can from there extract the path to load. [b]Be very careful when you start using this in your open statement.[/b] Otherwise, you will give people access to virtually everything on the server that the user the server is running as has access to. Think hard about sequences of ../'s and the like, and how you will handle them and make sure the user can't access stuff they can't. Feel free to post that bit of your code here for anyone who stumbles by to glance over it.
  
  Hope this helps,
  
  Jonathan
  
  ###
  for(74,117,115,116){$::a.=chr};(($_.='qwertyui')&&
  (tr/yuiqwert/her anot/))for($::b);for($::c){$_.=$^X;
  /(p.{2}l)/;$_=$1}$::b=~/(..)$/;print("$::a$::b $::c hack$1.");
  
  
• eatfishcracker

  February 2004

  I got the server more functional than before...
  I can only read the last line of a file- therefore causing me to put all of my HTML code on one line...
  im newbie to perl so i don't really know how to fix that.
  It works though- it opens the file and reads it to the browser- the one problem i would have is that I cannot have links to other pages on my server. I have no idea how i would be able to do that- and as the code is right now- its not possible because I am piping data from one file and that file isnt exactly a file manager...
  code for the server below...
  
  use IO::Socket::INET;
  #create socket
  my $sock = new IO::Socket::INET->new(
  LocalPort => '80',
  Proto => 'tcp',
  Listen => 1,
  Reuse => 1,
  );
  #error handling
  die "Could not create socket: $!
  " unless $sock;
  #tell user that server is running
  print "Server running on port 80";
  #loop the accept clients- so that it doesn't close after serving once
  for ($count=1; $count<11; $count++){
  #accept clients
  my $new_sock = $sock->accept();
  #if a client comes, send the following info
  if(defined(<$new_sock>)) {
  #mandatory statement
  print $_;
  #file piping below. HTML files created must be 1 line long- you can just have all of
  #your HTML code on one line. it'll still work but its still a problem
  
  open ( FH, "C:\windows\desktop\index.html");
  while( )
  {
  $FileContent = $_;
  }
  close ( FH );
  
  #send the message
  $new_sock->send($FileContent);
  #close up shop
  }
  }
  
  
  
• Jonathan

  February 2004

  : I got the server more functional than before...
  : I can only read the last line of a file- therefore causing me to put
  : all of my HTML code on one line...
  That's because:-
  
  : while( )
  : {
  : $FileContent = $_;
  : }
  You should be using .= instead of =. In the while loop each line of the file is put into $_ each time you loop. You are over-writing $FileContent with the contents of the line just read in. You need to instead concatenate it onto what you've already read, which is what .= does.
  
  [code]while () {
  $FileContent .= $_;
  }[/code]
  
  : im newbie to perl so i don't really know how to fix that.
  No worries, that's what this board is for. :-) Another way to do it, FYI, is:-
  $FileContent = join('', );
  Which puts into array context, and it returns an array of all lines which we then join. Not sure it's the most efficient way, but it's a common idiom. The other way is:-
  
  [code]{
  local $/ = undef;
  $FileContent = :
  }[/code]
  Here we undefine $/, which stops the file just being read line by line and reads the lot ($/ is the input seperator, and defaults to
  ). Note how we put that in a closure and use local, so it only affects that particular read.
  
  : It works though- it opens the file and reads it to the browser- the
  : one problem i would have is that I cannot have links to other pages
  : on my server. I have no idea how i would be able to do that- and as
  : the code is right now- its not possible because I am piping data
  : from one file and that file isnt exactly a file manager...
  
  
  : #loop the accept clients- so that it doesn't close after serving once
  : for ($count=1; $count<11; $count++){
  : #accept clients
  : my $new_sock = $sock->accept();
  : #if a client comes, send the following info
  : if(defined(<$new_sock>)) {
  : #mandatory statement
  : print $_;
  What does $_ contain here? Note that to know what file to serve, you need to read data that was sent by the client.
  
  : #send the message
  : $new_sock->send($FileContent);
  Would you not have to sent a Content-type header before doing this?
  
  Jonathan
  
  ###
  for(74,117,115,116){$::a.=chr};(($_.='qwertyui')&&
  (tr/yuiqwert/her anot/))for($::b);for($::c){$_.=$^X;
  /(p.{2}l)/;$_=$1}$::b=~/(..)$/;print("$::a$::b $::c hack$1.");