Answer Posted / chaitanya
Use the getservbyname() routine. This will return a pointer to a servent structure. You are interested in the s_port field, which contains the port number, with correct byte ordering (so you don't need to call htons() on it). Here is a sample routine:
/* Take a service name, and a service type, and return a port number. If the service name is not found, it tries it as a decimal number. The number returned is byte ordered for the network. */
int atoport(char *service, char *proto)
{
int port;
long int lport;
struct servent *serv;
char *errpos;
/* First try to read it from /etc/services */
serv = getservbyname(service, proto);
if (serv != NULL)
port = serv->s_port;
else {
/* Not in services, maybe a number? */
lport = strtol(service,&errpos,0);
if ( (errpos[0] != 0) || (lport < 1)
|| (lport > 5000) )
return -1;
/* Invalid port address */
port = htons(lport);
}
return port;
}
| Is This Answer Correct ? | 0 Yes | 0 No |
Post New Answer View All Answers
What is af_inet in socket?
What does af mean in sockets?
What's the difference between impact sockets and regular sockets?
How can I set the timeout for the connect() system call?
Are sockets files?
Where is the socket located?
Is tcp or unix socket faster?
How many socket connections can a server handle?
What is a deep well socket?
What is the purpose of socket?
What pieces of information make up a socket?
What is the difference between a socket and a port?
What's better 6pt or 12pt sockets?
Why does the sockets buffer fill up sooner than expected?
How do I convert a string into an internet address?
