upscli_list_next(3)

1UPSCLI_LIST_NEXT(3)               NUT Manual               UPSCLI_LIST_NEXT(3)
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NAME

6       upscli_list_next - retrieve list items from a UPS
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SYNOPSIS

9       #include <upsclient.h>
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11       int upscli_list_next(UPSCONN_t *ups, size_t numq, const char **query,
12                              size_t *numa, char ***answer)
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DESCRIPTION

15       The upscli_list_next() function takes the pointer ups to a UPSCONN_t
16       state structure, and the pointer query to an array of numq query
17       elements. It performs a read from the network and expects to find
18       either another list item or the end of a list.
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20       You must call upscli_list_start(3) before calling this function.
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22       This function will return 1 and set values in numa and answer if a list
23       item is received. If the list is done, it will return 0, and the values
24       in numa and answer are undefined.
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26       Calling this function after it returns something other than 1 is
27       undefined.
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QUERY FORMATTING

30       You may not change the values of numq or query between the call to
31       upscli_list_start(3) and the first call to this function. You also may
32       not change the values between calls to this function.
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ANSWER FORMATTING

35       The contents of numa and answer work just like a call to upscli_get(3).
36       The values returned by upsd(8) are identical to a single item request,
37       so this is not surprising.
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ERROR CHECKING

40       This function checks the response from upsd(8) against your query. If
41       the response is not part of the list you have requested, it will return
42       an error code.
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44       When this happens, upscli_upserror(3) will return UPSCLI_ERR_PROTOCOL.
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RETURN VALUE

47       The upscli_list_next() function returns 1 when list data is present, 0
48       if the list is finished, or -1 if an error occurs.
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50       It is possible to have an empty list. The function will return 0 for
51       its first call in that case.
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