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.

SEE ALSO

getnetent(3), getprotoent(3), services(5)

COLOPHON

This page is part of release 2.79 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/.


  Copyright 1993 David Metcalfe (davidprism.demon.co.uk)

Permission is granted to make and distribute verbatim copies of this
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Since the Linux kernel and libraries are constantly changing, this
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Formatted or processed versions of this manual, if unaccompanied by
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References consulted:
    Linux libc source code
    Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
    386BSD man pages
Modified Sat Jul 24 19:19:11 1993 by Rik Faith (faithcs.unc.edu)
Modified Wed Oct 18 20:23:54 1995 by Martin Schulze <joeyinfodrom.north.de>
Modified Mon Apr 22 01:50:54 1996 by Martin Schulze <joeyinfodrom.north.de>
2001-07-25 added a clause about NULL proto (Martin Michlmayr or David N. Welton)