Sun Java System Web Server 6.1 SP6 NSAPI Programmer's Guide


The net_sendfile function sends the contents of a specified file to a specified socket. Either the whole file or a fraction may be sent, and the contents of the file may optionally be preceded and/or followed by caller-specified data.

Parameters are passed to net_sendfile in the sendfiledata structure. Before invoking net_sendfile, the caller must initialize every sendfiledata structure member.


int net_sendfile(SYS_NETFD sd, const sendfiledata *sfd);


A positive number indicates the number of bytes successfully written, including the headers, file contents, and trailers. A negative value indicates an error.


SYS_NETFD sd is the socket to write to.

const sendfiledata *sfd identifies the data to send.


The following Service SAF sends a file bracketed by the strings "begin" and "end."

#include <string.h>
#include "nsapi.h"

NSAPI_PUBLIC int service_net_sendfile(pblock *pb, Session *sn, Request *rq)
    char *path;
    SYS_FILE fd;
    struct sendfiledata sfd;
    int rv;

    path = pblock_findval("path", rq->vars);
    fd = system_fopenRO(path);
    if (!fd) {
        log_error(LOG_MISCONFIG, "service-net-sendfile", sn, rq,
                  "Error opening %s (%s)", path, system_errmsg());
        return REQ_ABORTED;

    sfd.fd = fd;                         /* file to send */
    sfd.offset = 0;                       /* start sending from the beginning */
    sfd.len = 0;                         /* send the whole file */
    sfd.header = "begin";               /* header data to send before the file */
    sfd.hlen = strlen(sfd.header);        /* length of header data */
    sfd.trailer = "end";                /* trailer data to send after the file */
    sfd.tlen = strlen(sfd.trailer);       /* length of trailer data */

    /* send the headers, file, and trailers to the client */
    rv = net_sendfile(sn->csd, &sfd);


    if (rv < 0) {
        log_error(LOG_INFORM, "service-net-sendfile", sn, rq,"Error sending %s 
(%s)", path, system_errmsg());
        return REQ_ABORTED;

    return REQ_PROCEED;

See Also