getservent, getservbyname, getservbyport, setservent, endservent — get service entry
#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); |
The getservent() function
reads the next entry from the services database (see
services(5)) and returns a
servent structure containing
the broken-out fields from the entry. A connection is opened
to the database if necessary.
The getservbyname() function
returns a servent structure
for the entry from the database that matches the service
name using protocol
proto. If proto is NULL, any protocol
will be matched. A connection is opened to the database if
necessary.
The getservbyport() function
returns a servent structure
for the entry from the database that matches the port
port (given in
network byte order) using protocol proto. If proto is NULL, any protocol
will be matched. A connection is opened to the database if
necessary.
The setservent() function
opens a connection to the database, and sets the next entry
to the first entry. If stayopen is nonzero, then the
connection to the database will not be closed between calls
to one of the getserv*()
functions.
The endservent() function
closes the connection to the database.
The servent structure is
defined in <netdb.h> as
follows:
struct servent { char * s_name;char ** s_aliases;int s_port;char * s_proto;};
The members of the servent structure are:
s_nameThe official name of the service.
s_aliasesA NULL-terminated list of alternative names for the service.
s_portThe port number for the service given in network byte order.
s_protoThe name of the protocol to use with this service.
The getservent(),
getservbyname() and
getservbyport() functions
return a pointer to a statically allocated servent structure, or NULL if an error
occurs or the end of the file is reached.
For an explanation of the terms used in this section, see attributes(7).
| Interface | Attribute | Value |
getservent() |
Thread safety |
MT-Unsafe race:servent race:serventbuf locale |
getservbyname() |
Thread safety |
MT-Unsafe race:servbyname locale |
getservbyport() |
Thread safety |
MT-Unsafe race:servbyport locale |
|
|
Thread safety |
MT-Unsafe race:servent locale |
In the above table, servent in race:servent signifies that
if any of the functions setservent(3), getservent(3), or endservent(3) are used in
parallel in different threads of a program, then data races
could occur.
This page is part of release 4.07 of the Linux man-pages project. A
description of the project, information about reporting bugs,
and the latest version of this page, can be found at
https://www.kernel.org/doc/man−pages/.
|
Copyright 1993 David Metcalfe (davidprism.demon.co.uk) %%%LICENSE_START(VERBATIM) Permission is granted to make and distribute verbatim copies of this manual provided the copyright notice and this permission notice are preserved on all copies. Permission is granted to copy and distribute modified versions of this manual under the conditions for verbatim copying, provided that the entire resulting derived work is distributed under the terms of a permission notice identical to this one. Since the Linux kernel and libraries are constantly changing, this manual page may be incorrect or out-of-date. The author(s) assume no responsibility for errors or omissions, or for damages resulting from the use of the information contained herein. The author(s) may not have taken the same level of care in the production of this manual, which is licensed free of charge, as they might when working professionally. Formatted or processed versions of this manual, if unaccompanied by the source, must acknowledge the copyright and authors of this work. %%%LICENSE_END 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) |