UPSCLIENT(3)                      NUT Manual                      UPSCLIENT(3)



NAME
       upsclient - Network UPS Tools client access library

DESCRIPTION
       The Network UPS Tools (NUT) upsclient library provides a number of
       useful functions for programs to use when communicating with upsd(8).
       Many of the low-level socket and protocol details are handled
       automatically when using this interface.

       State is maintained across calls in an opaque structure called
       UPSCONN_t. Callers are expected to create one per connection. These
       will be provided to most of the upsclient functions. The format of this
       structure is subject to change, and client programs must not reference
       elements within it directly.

INITIALIZATION AND CLEANUP
       Before creating any connection, and in general using any upscli
       function, you must call upscli_init(3) with proper parameters to
       initialize upscli module.

       To register specific host security policy, you must call
       upscli_add_host_cert(3) before initialize connection to it.

       In the same way, just before exiting, and after all upscli usage, you
       must call upscli_cleanup(3) to flush cache files and perform other
       cleanup.

NETWORK FUNCTIONS
       To create a new connection, use upscli_connect(3). This will also
       initialize the UPSCONN_t structure. To verify that a connection has
       been established later, upscli_fd(3) can be used to return the file
       descriptor. Clients wishing to check for the presence and operation of
       SSL on a connection may call upscli_ssl(3).

       The majority of clients will use upscli_get(3) to retrieve single items
       from the server. To retrieve a list, use upscli_list_start(3) to get it
       started, then call upscli_list_next(3) for each element.

       Raw lines of text may be sent to upsd(8) with upscli_sendline(3).
       Reading raw lines is possible with upscli_readline(3). Client programs
       are expected to format these lines according to the protocol, as no
       checking will be performed before transmission.

       At the end of a connection, you must call upsclient_disconnect(3) to
       disconnect from upsd and release any dynamic memory associated with the
       UPSCONN_t structure. Failure to call this function will result in
       memory and file descriptor leaks in your program.

ERROR HANDLING
       In the event of an error, upscli_strerror(3) will provide
       human-readable details on what happened. upscli_upserror(3) may also be
       used to retrieve the error number. These numbers are defined in
       upsclient.h as UPSCLI_ERR_*.

SEE ALSO
       libupsclient-config(1), upscli_init(3), upscli_cleanup(3),
       upscli_add_host_cert(3), upscli_connect(3), upscli_disconnect(3),
       upscli_fd(3), upscli_getvar(3), upscli_list_next(3),
       upscli_list_start(3), upscli_readline(3), upscli_sendline(3),
       upscli_splitaddr(3), upscli_splitname(3), upscli_ssl(3),
       upscli_strerror(3), upscli_upserror(3)



Network UPS Tools 2.7.3.          03/02/2016                      UPSCLIENT(3)
