Get current error number for connection
#include <upsclient.h>
int upscli_upserror(UPSCONN_t *ups);
The upscli_upserror() function takes the pointer ups to a UPSCONN_t state structure and returns the value of the internal error number, if any.
This is typically used to check for certain error values like UPSCLI_ERR_UNKCOMMAND. That specific error can be used for detecting older versions of upsd(8) which might not support a given command.
Some error messages have additional meanings, so you should use upscli_strerror(3) to obtain readable error messages.
The upscli_upserror() function returns one of the UPSCLI_ERR_* values from upsclient.h, or 0 if no error has occurred.