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)