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)

EPFL                                                  2010                                    XDF_ADD_CHANNEL(3)