Getting Started with QNX Neutrino - QNX Software Systems

© 2009, QNX Software Systems GmbH & Co. KG. atoz.c
}
// tell resource manager library we already did the reply
return (_RESMGR_NOREPLY);
static int
my_read_file (resmgr_context_t *ctp, io_read_t *msg, iofunc_ocb_t *ocb)
{
int nbytes;
int nleft;
char string;
// we don’t do any xtypes here...
if ((msg -> i.xtype & _IO_XTYPE_MASK) != _IO_XTYPE_NONE) {
return (ENOSYS);
}
// figure out how many bytes are left
nleft = ocb -> attr -> nbytes - ocb -> offset;
// and how many we can return to the client
nbytes = min (nleft, msg -> i.nbytes);
if (nbytes) {
// create the output string
string = ocb -> attr -> inode - 1 + ’A’;
// return it to the client
MsgReply (ctp -> rcvid, nbytes, &string + ocb -> offset, nbytes);
// update flags and offset
ocb -> attr -> flags |= IOFUNC_ATTR_ATIME | IOFUNC_ATTR_DIRTY_TIME;
ocb -> offset += nbytes;
} else {
// nothing to return, indicate End Of File
MsgReply (ctp -> rcvid, EOK, NULL, 0);
}
}
// already done the reply ourselves
return (_RESMGR_NOREPLY);
static int
my_read (resmgr_context_t *ctp, io_read_t *msg, iofunc_ocb_t *ocb)
{
int sts;
// use the helper function to decide if valid
if ((sts = iofunc_read_verify (ctp, msg, ocb, NULL)) != EOK) {
return (sts);
}
}
// decide if we should perform the "file" or "dir" read
if (S_ISDIR (ocb -> attr -> mode)) {
return (my_read_dir (ctp, msg, ocb));
} else if (S_ISREG (ocb -> attr -> mode)) {
return (my_read_file (ctp, msg, ocb));
} else {
return (EBADF);
}
int
main (int argc, char **argv)
April 30, 2009 Appendix: C • Sample Programs 315