NAME

       Ns_ConnCondSetHeaders,             Ns_ConnSetExpiresHeader,             Ns_ConnSetHeaders,
       Ns_ConnSetLastModifiedHeader, Ns_ConnSetLengthHeader, Ns_ConnSetRequiredHeaders - Routines
       to manage response headers

SYNOPSIS

       #include "ns.h"

       void
       Ns_ConnCondSetHeaders(conn, key, value)

       void
       Ns_ConnSetExpiresHeader(conn, expires)

       void
       Ns_ConnSetHeaders(conn, key, value)

       void
       Ns_ConnSetLastModifiedHeader(conn, mtime)

       void
       Ns_ConnSetLengthHeader(conn, length)

       void
       Ns_ConnSetRequiredHeaders(conn, type, length)

       void
       Ns_ConnSetTypeHeader(conn, type)

ARGUMENTS

       Ns_Conn   conn   (in)      Pointer to open connection.

       char      *expires(in)     Pointer to string to construct an expires header.

       char      *key   (in)      Pointer to string key for a header.

       int       length (in)      Integer  length of output content to construct a content-length
                                  header.

       time_t    mtime  (in)      Modification time stamp to construct a last-modified header.

       int       status (in)      HTTP result status code.

       char      *type  (in)      Pointer to mimetype string to construct a content-type header.

       char      *value (in)      Pointer to a string value for a header.
_________________________________________________________________

DESCRIPTION

       These functions  manage  the  output  headers  eventually  sent  through  the  given  open
       connection  to  a  client.   They  operate  by  modifying  the outputheaders Ns_Set of the
       connection Ns_Conn structure.  Headers can be modified  until  they  are  queued  or  sent
       directly  via  the Ns_ConnQueueHeaders or Ns_ConnFlushHeaders routines.  It is possible to
       modify the outputheaders directly  although  use  of  these  functions  is  preferred  for
       consistancy.

       Note  that  higher level output routines such as Ns_ConnFlush or the various Ns_ConnReturn
       routines normally generate all the headers necessary for a given response.  These routines
       are  normally only necessary for specialized applications which output additional specific
       headers or specialized request procedures  which  do  not  use  the  higher  level  output
       routines.

       void Ns_ConnCondSetHeaders(conn, key, value)
              Append  an output header of the form key: value only if the header does not already
              exist in the outputheaders set.

       void Ns_ConnSetExpiresHeader(conn, expires)
              This routine is equivalent to Ns_ConnSetHeaders(conn,  "Expires",  expires).   Note
              that the exires parameter is treated as a string, not a timestamp.  A timestamp can
              be constructed with the Ns_HttpTime routine.

       void Ns_ConnSetHeaders(conn, key, value)
              Append a header of the form key: value to the  outputheaders.   This  routine  will
              append  a  new,  possibly duplicate, header regardless of whether a matching header
              already exists in the outputheaders.

       void Ns_ConnSetLastModifiedHeader(conn, mtime)
              This routine appends a  last-modified  header  if  one  does  not  already  exists,
              formatting  the  given  modification  time  as  a  proper  HTTP  timestamp with the
              Ns_HttpTime routine.

       void Ns_ConnSetLengthHeader(conn, length)
              This routine appends a content-length: length header, formatting the given  integer
              length  as  a string.  This routine will also record the response length internally
              in  the  conn  structure  so   that   it   can   be   later   retrieved   via   the
              Ns_ConnResponseLength  routine,  for  example, as part of a post-connection logging
              callback.

       void Ns_ConnSetRequiredHeaders(conn, type, length)
              This routine appends  the  basic  headers  normally  required  for  a  proper  HTTP
              transaction.   These include mime-version, date, and server as well as the content-
              type: type and content-length: length headers for the given arguments.  If type  is
              NULL  or  length is less than zero, the corresponding headers will not be appended.
              This routine is often the only header construction routine  necessary  for  request
              procedures  which  construct  headers  manually instead of calling routines such as
              Ns_ConnFlush which handle header construction and queueing automatically.

       void Ns_ConnSetTypeHeader(conn, type)
              This routine is equivalent to Ns_ConnSetHeaders(conn, "content-type", type).

SEE ALSO

       Ns_ConnQueueHeaders(3), Ns_ConnFlushHeaders(3), Ns_ConnFlush(3)

KEYWORDS

       headers, response