NAME

       upscli_list_start - begin multi-item retrieval from a UPS

SYNOPSIS

       #include <upsclient.h>

       int upscli_list_start(UPSCONN_t *ups, unsigned int numq, const char **query)

DESCRIPTION

       The upscli_list_start() function takes the pointer ups to a UPSCONN_t state structure, and
       the pointer query to an array of numq query elements. It builds a properly-formatted
       request from those elements and transmits it to upsd(8).

       Upon success, the caller must call upscli_list_next(3) to retrieve the elements of the
       list. Failure to retrieve the list will most likely result in the client getting out of
       sync with the server due to buffered data.

USES

       This function implements the "LIST" command in the protocol. As a result, you can use it
       to request many different things from the server. Some examples are:

       •   LIST UPS

       •   LIST VAR <ups>

       •   LIST RW <ups>

       •   LIST CMD <ups>

       •   LIST ENUM <ups> <var>

       •   LIST RANGE <ups> <var>

QUERY FORMATTING

       To see the list of variables on a UPS called su700, the protocol command would be LIST VAR
       su700. To start that list with this function, you would populate query and numq as
       follows:

           unsigned int numq;
           const char *query[2];

           query[0] = "VAR";
           query[1] = "su700";
           numq = 2;

       All escaping of special characters and quoting of elements with spaces are handled for you
       inside this function.

ERROR CHECKING

       This function checks the response from upsd(8) against your query. If it is not starting a
       list, or is starting the wrong type of list, it will return an error code.

       When this happens, upscli_upserror(3) will return UPSCLI_ERR_PROTOCOL.

RETURN VALUE

       The upscli_list_start() function returns 0 on success, or -1 if an error occurs.

SEE ALSO

       upscli_fd(3), upscli_get(3), upscli_readline(3), upscli_sendline(3), upscli_ssl(3),
       upscli_strerror(3), upscli_upserror(3)