Ns httpopen

<manpage>ns_httpopen</manpage>

NAME

ns_httpopen - Fetch a web page

SYNOPSIS

ns_httpopen method url ?rqset? ?timeout? ?pdata?

DESCRIPTION

This command opens an http connection to a web page used to fetch its contents via the method, which may be POST, GET, or another valid http method. If the act of opening the connections fails, it may throw an error.

The url may be either absolute (http://server/page) or local (/page). If it is local, the host and port number of the server are added.

The parameter rqset is the handle for an ns_set containing headers to send with the request. The timeout is the number of seconds to wait for the connection to open. Pdata is the extra data to send with the request (i.e. post data). If pdata is specified, the caller is responsible for supplying the Content-length and Content-type headers in rqset

The call returns a list with these three elements: a file descriptor for reading, a file descriptor for writing, and a set ID for a set describing the connection.

Note: This command is currently implemented in Tcl, in the source file tcl/http.tcl

EXAMPLES

   % # A proc to post some data to a url and return the result
   % proc postit {url data} {
         set rqset ns_set new rqset
         ns_set put $rqset "Accept" "*/*"
         ns_set put $rqset "User-Agent" "ns_info name-Tcl/ns_info version"
         ns_set put $rqset "Content-type" "text/xml"
         ns_set put $rqset "Content-length" string length $data

         set timeout 15

         set connInfo ns_httpopen POST $url $rqset $timeout $data

         foreach {rfd wfd headers} $connInfo {break}
         close $wfd

         set length ns_set iget $headers content-length
         if {string match "" $length} {
             set length -1
         }

         set page ""
         set err [[catch {
             # Read the content.
             while {1} {
                 set buf [_ns_http_read $timeout $rfd $length]]
                 append page $buf
                 if {string match "" $buf} {
                     break
                 }
                 if {$length > 0} {
                     incr length -string length $buf
                     if {$length <= 0} {
                         break
                     }
                 }
             }
         } errMsg]

         ns_set free $headers
         close $rfd
         if {$err} {
             global errorInfo
             return -code error -errorinfo $errorInfo $errMsg
         }
         return $page
     }

SEE ALSO

ns_http, ns_httpget, ns_httppost