getservbyport

getservbyport

Gets Service Information by Port

Portability: UNIX compatible

SYNOPSIS
DESCRIPTION
RETURN VALUE
CAUTION
PORTABILITY
IMPLEMENTATION
RELATED FUNCTIONS

SYNOPSIS

#include <netdb.h>

struct servent *getservbyport(int port, const char *proto);

DESCRIPTION

Given the port of a well-known service, identified by the port argument, and the protocol string for accessing it, pointed to by proto , getservbyport returns a pointer to the servent structure, which is defined in <netdb.h> . This structure is typically used to obtain the name of the service from the s_name field. The source of the data in this structure is the services file, that is, a file with the same format as the /etc/services file on a UNIX operating system. Refer to <netdb.h> for details on the servent structure.

Refer to Search Logic for information on the logic used to determine the location of the services file.

RETURN VALUE

If getservbyport succeeds, it returns a pointer to the matching port number in the servent structure. A null pointer indicates an error occurred or there were no more network entries.

CAUTION

The value that getservbyport returns points to a static structure within the library. You must copy the information from this structure before you make further getservbname , getservbyport , or getservent calls.

PORTABILITY

getservbyport is portable to other environments, including most UNIX systems, that implement BSD sockets.

IMPLEMENTATION

getservbyport is ported directly from the BSD UNIX Socket Library.

RELATED FUNCTIONS

endservent , setservent , getservent , getservbyname

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