NAME¶
upscli_list_next - retrieve list items from a UPS
SYNOPSIS¶
#include <upsclient.h>
int upscli_list_next(UPSCONN_t *ups, int numq, const char **query,
int *numa, char ***answer)
DESCRIPTION¶
The
upscli_list_next() function takes the pointer
ups to a
UPSCONN_t state structure, and the pointer
query to an array of
numq query elements. It performs a read from the network and expects to
find either another list item or the end of a list.
You must call
upscli_list_start(3) before calling this function.
This function will return 1 and set values in
numa and
answer if a
list item is received. If the list is done, it will return 0, and the values
in
numa and
answer are undefined.
Calling this function after it returns something other than 1 is undefined.
You may not change the values of
numq or
query between the call to
upscli_list_start(3) and the first call to this function. You also may
not change the values between calls to this function.
The contents of
numa and
answer work just like a call to
upscli_get(3). The values returned by
upsd(8) are identical to a
single item request, so this is not surprising.
ERROR CHECKING¶
This function checks the response from
upsd(8) against your query. If the
response is not part of the list you have requested, it will return an error
code.
When this happens,
upscli_upserror(3) will return UPSCLI_ERR_PROTOCOL.
RETURN VALUE¶
The
upscli_list_next() function returns 1 when list data is present, 0 if
the list is finished, or -1 if an error occurs.
It is possible to have an empty list. The function will return 0 for its first
call in that case.
SEE ALSO¶
upscli_list_start(3),
upscli_strerror(3),
upscli_upserror(3)
