NAME

       xdf_add_channel - Appends a channel to a XDF file

SYNOPSIS

       #include <xdfio.h>

       struct xdfch* xdf_add_channel(struct xdf* xdf, const char* label);

DESCRIPTION

       xdf_add_channel()  appends  a  channel  to  the file referenced by the handle xdf. The new
       channel is initialized with the label argument (if not NULL) and with the default  channel
       values  set  in  the  XDF  file,  i.e.  those  set  using  channel configuration fields in
       xdf_set_conf(3) (See the related manpage).

       If the call to xdf_add_channel(3) is successful,  the  default  offset  value  (the  field
       referenced  by  XDF_CF_ARROFFSET) is incremented by the size of the current default stored
       type (field referenced by XDF_CF_STOTYPE). As a consequence, if the channel default values
       have  not  changed  in-between,  the  next call to xdf_add_channel() will create a channel
       whose location is the array will be next to the previous one.

       This type of initialization allows the user to add channels without having to specifically
       pack them: this is achieved by default.

RETURN VALUE

       xdf_add_channel()  returns  the  handle  to  newly  created  channel descriptor in case of
       success. Otherwise NULL is returned  and errno is set appropriately.

ERRORS

       EINVAL xdf is NULL.

       ENOMEM The system is unable to allocate resources.

       EPERM  the file referenced by xdf has been opened with the mode XDF_READ

SEE ALSO

       xdf_copy_chconf(3), xdf_set_conf(3), xdf_set_chconf(3)