NAME
upscli_connect - Open a connection to a NUT upsd
SYNOPSIS
#include <upsclient.h>int upscli_connect(UPSCONN_t *ups, const char *host, uint16_t port, int flags);DESCRIPTION
The upscli_connect() function takes the pointer ups to a
UPSCONN_t state structure and opens a TCP connection to the host on
the given port.
flags may be either UPSCLI_CONN_TRYSSL to try a SSL
connection, or UPSCLI_CONN_REQSSL to require a SSL connection.
Introduced in version 2.7, an additional flag UPSCLI_CONN_CERTVERIF
now exists to verify the signature offered during the SSL handshake.
This flag should be used in conjunction with upscli_init(3)
and/or upscli_add_host_cert(3) calls before connecting in
order to define a CA certificate with which to verify.
If SSL mode is required, this function will only return successfully if it is able to establish a SSL connection with the server. Possible reasons for failure include no SSL support on the server, and if upsclient itself hasn’t been compiled with SSL support.
You must call upscli_disconnect(3) when finished with a connection, or your program will slowly leak memory and file descriptors.
RETURN VALUE
The upscli_connect() function modifies the UPSCONN_t structure and
returns 0 on success, or -1 if an error occurs.