Golgappa.net | Golgappa.org | BagIndia.net | BodyIndia.Com | CabIndia.net | CarsBikes.net | CarsBikes.org | CashIndia.net | ConsumerIndia.net | CookingIndia.net | DataIndia.net | DealIndia.net | EmailIndia.net | FirstTablet.com | FirstTourist.com | ForsaleIndia.net | IndiaBody.Com | IndiaCab.net | IndiaCash.net | IndiaModel.net | KidForum.net | OfficeIndia.net | PaysIndia.com | RestaurantIndia.net | RestaurantsIndia.net | SaleForum.net | SellForum.net | SoldIndia.com | StarIndia.net | TomatoCab.com | TomatoCabs.com | TownIndia.com
Interested to Buy Any Domain ? << Click Here >> for more details...

How do I get the port number for a given service?

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


Please Help Members By Posting Answers For Below Questions

How does unix socket work?

922


What is socket address with example?

864


Why do we need socket programming?

883


What's the difference between a socket and a port?

847


How many sockets can a port have?

871


How can I force a socket to send the data in its buffer?

1621


What is the difference between SO_REUSEADDR and SO_REUSEPORT?

1811


What is a socket address?

926


What are the types of sockets?

939


How are unix domain sockets implemented?

863


What are the pros/cons of select(), non-blocking I/O and SIGIO?

1367


How many socket connections can a server handle?

866


Where is the socket located?

904


What is a deep well socket?

931


How can I write a multi-homed server?

1655