Metrologic Optimus R, Руководство по программированию

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Chapter 3 Terminal Specific Function Library 167
socket_hasdata
Purpose To check if data is available.
Syntax int socket_hasdata (int conno);
int conno; /* connection number */
Example if (socket_hasdata (conno))
Nread (conno, buf, sizeof (buf));
Description This function checks if data from the connection specified conno is available to
be read.
Return If available, it returns a non-zero value.
Otherwise, it returns 0.
See Also Nread, recv
socket_ipaddr
Purpose
To get the IP address of the remote end of a connection.
Syntax int socket_ipaddr (int conno, char *ipaddr);
int conno; /* connection number */
char *ipaddr; /* pointer to IP address returned */
Example unsigned char ip[4];
socket_ipaddr (conno, ip);
printf ("Remote IP: %d.%d.%d.%d\r\n", ip[0], ip[1], ip[2], ip[3]);
Description This function copies the remote host IP address of the connection specified by
conno
into a buffer indicated by
ipaddr
.
No string terminator is appended by this function.
Return If successful, it returns 0.
On error, it returns a negative value. (?)
See Also getpeername
socket_isopen
Purpose
To check if the remote end of a connection is open.
Syntax int socket_isopen (int conno);
int conno; /* connection number */
Example if (socket_isopen (conno)) printf ("connected!!");
Description
This function checks if the remote end has entered the ESTABLISHED state.
(TCP only)