getservent() — Get the next service entry

Standards

Standards / Extensions C or C++ Dependencies

XPG4.2
Single UNIX Specification, Version 3

 both  

Format

X/Open: 
#define _XOPEN_SOURCE_EXTENDED 1
#include <netdb.h>

struct servent *getservent(void);
Berkeley sockets: 
#define _OE_SOCKETS
#include <netdb.h>

struct servent *getservent(void);

General description

The getservent() call reads the next line of the /etc/services or the tcpip.ETC.SERVICES data set.

The getservent() call returns a pointer to the next entry in the /etc/services or the tcpip.ETC.SERVICES data set.

getservbyname(), getservbyport(), and getservent() all use the same static area to return the servent structure. This static area is only valid until the next one of these functions is called on the same thread.

The servent structure is defined in the netdb.h include file and contains the following elements:
Element
Description
s_aliases
An array, terminated with a NULL pointer, of alternative names for the service.
s_name
The official name of the service.
s_port
The port number of the service.
s_proto
The protocol required to contact the service.

Special behavior for C++: To use this function with C++, you must use the _XOPEN_SOURCE_EXTENDED 1 feature test macro.

Returned value

The return value points to data that is overwritten by subsequent calls returning the same data structure.

If successful, getservent() returns a pointer to a servent structure.

If unsuccessful or End Of File (EOF), getservent() returns a NULL pointer.

Related information

Parent topic: Library functions