Interested to Buy Any Domain ? << Click Here >> for more details...
How do I get the port number for a given service?
- 1 Answers
- 2492 Views
- I also Faced
- E-Mail Answers
Answer / 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 |
How would I put my socket in non-blocking mode?
What is a sae socket?
What is sae socket?
How can I find the full hostname (FQDN) of the system I am running on?
Where can a get a library for programming sockets?
What exactly does SO_KEEPALIVE do?
What exactly does SO_REUSEADDR do?
How do I get my server to find out the clients address / host- name?
Is tcp or unix socket faster?
What is the difference between close() and shutdown()?
How can I write a multi-homed server?
How can I bind() to a port number < 1024?
Unix Commands 
