Metrologic Optimus R, Руководство по программированию

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Chapter 3 Terminal Specific Function Library 165
Supplemental Functions
Other useful functions for obtaining additional information or setting control for a
connection are described below.
Nportno
Purpose To get an ephemeral port number.
Syntax int Nportno (void);
Example if ((conno = Nopen (remote_ip, "TCP/IP", Nportno(), 2000, 0)) < 0)
Printf ("Fail to connect Host: %s\r\n", remote_ip);
Description This function generates a random local port number, which is used in a active
open call to the Nopen() function.
Return It always returns the port number.
See Also Nopen
DNS_resolver
Purpose To get the remote IP address by remote name.
Syntax int DNS_resolver (const char *remote_host, char *remote_ip);
const char *remote_host; /* remote name */
char *remote_ip; /* pointer to remote_ip returned */
Example char IP[4];
DNS_resolver ("www.metrologic.com", IP);
Description This function gets the remote IP address by remote name. It is necessary to
define the DNS server IP before calling this function.
Return
If successful, it returns 0.
On error, it returns a negative value. (?)
See Also gethostbyname
socket_block
Purpose
To set the connection for blocking operation.
Syntax
int socket_block (int conno);
int conno; /* connection number */
Example socket_block (conno)