GETSERVENT

Section: Linux Programmer's Manual (3)
Updated: 2001-07-25
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NAME

getservent, getservbyname, getservbyport, setservent, endservent - get service entry

SYNOPSIS

#include <netdb.h>

struct servent *getservent(void);

struct servent *getservbyname(const char *name, const char *proto);

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

void setservent(int stayopen);

void endservent(void);

DESCRIPTION

The getservent() function reads the next line from the file /etc/services and returns a structure servent containing the broken out fields from the line. The /etc/services file is opened if necessary.

The getservbyname() function returns a servent structure for the line from /etc/services that matches the service name using protocol proto. If proto is NULL, any protocol will be matched.

The getservbyport() function returns a servent structure for the line that matches the port port given in network byte order using protocol proto. If proto is NULL, any protocol will be matched.

The setservent() function opens and rewinds the /etc/services file. If stayopen is true (1), then the file will not be closed between calls to getservbyname() and getservbyport().

The endservent() function closes /etc/services.

The servent structure is defined in <netdb.h> as follows:

struct servent {
    char  *s_name;       /* official service name */
    char **s_aliases;    /* alias list */
    int    s_port;       /* port number */
    char  *s_proto;      /* protocol to use */
}

The members of the servent structure are:

s_name: The official name of the service.
s_aliases: A zero terminated list of alternative names for the service.
s_port: The port number for the service given in network byte order.
s_proto: The name of the protocol to use with this service.

RETURN VALUE

The getservent(), getservbyname() and getservbyport() functions return the servent structure, or a NULL pointer if an error occurs or the end of the file is reached.

FILES

/etc/services: services database file

CONFORMING TO

4.3BSD, POSIX.1-2001.

COLOPHON

This page is part of release 3.05 of the Linux man-pages project. A description of the project, and information about reporting bugs, can be found at http://www.kernel.org/doc/man-pages/.