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