.\" Copyright (c) 2001-2003 The Open Group, All Rights Reserved 
.TH "ENDSERVENT" 3P 2003 "IEEE/The Open Group" "POSIX Programmer's Manual"
.\" endservent 
.SH PROLOG
This manual page is part of the POSIX Programmer's Manual.
The Linux implementation of this interface may differ (consult
the corresponding Linux manual page for details of Linux behavior),
or the interface may not be implemented on Linux.
.SH NAME
endservent, getservbyname, getservbyport, getservent, setservent \-
network services database functions
.SH SYNOPSIS
.LP
\fB#include <netdb.h>
.br
.sp
void endservent(void);
.br
struct servent *getservbyname(const char *\fP\fIname\fP\fB, const
char *\fP\fIproto\fP\fB);
.br
struct servent *getservbyport(int\fP \fIport\fP\fB, const char *\fP\fIproto\fP\fB);
.br
struct servent *getservent(void);
.br
void setservent(int\fP \fIstayopen\fP\fB);
.br
\fP
.SH DESCRIPTION
.LP
These functions shall retrieve information about network services.
This information is considered to be stored in a database
that can be accessed sequentially or randomly. The implementation
of this database is unspecified.
.LP
The \fIsetservent\fP() function shall open a connection to the database,
and set the next entry to the first entry. If the
\fIstayopen\fP argument is non-zero, the \fInet\fP database shall
not be closed after each call to the \fIgetservent\fP()
function (either directly, or indirectly through one of the other
\fIgetserv*\fP()
functions), and the implementation may maintain an open file descriptor
for the database.
.LP
The \fIgetservent\fP() function shall read the next entry of the database,
opening and closing a connection to the database as
necessary.
.LP
The \fIgetservbyname\fP() function shall search the database from
the beginning and find the first entry for which the service
name specified by \fIname\fP matches the \fIs_name\fP member and the
protocol name specified by \fIproto\fP matches the
\fIs_proto\fP member, opening and closing a connection to the database
as necessary. If \fIproto\fP is a null pointer, any value
of the \fIs_proto\fP member shall be matched.
.LP
The \fIgetservbyport\fP() function shall search the database from
the beginning and find the first entry for which the port
specified by \fIport\fP matches the \fIs_port\fP member and the protocol
name specified by \fIproto\fP matches the
\fIs_proto\fP member, opening and closing a connection to the database
as necessary. If \fIproto\fP is a null pointer, any value
of the \fIs_proto\fP member shall be matched. The \fIport\fP argument
shall be in network byte order.
.LP
The \fIgetservbyname\fP(), \fIgetservbyport\fP(), and \fIgetservent\fP()
functions shall each return a pointer to a
\fBservent\fP structure, the members of which shall contain the fields
of an entry in the network services database.
.LP
The \fIendservent\fP() function shall close the database, releasing
any open file descriptor.
.LP
These functions need not be reentrant. A function that is not required
to be reentrant is not required to be thread-safe.
.SH RETURN VALUE
.LP
Upon successful completion, \fIgetservbyname\fP(), \fIgetservbyport\fP(),
and \fIgetservent\fP() return a pointer to a
\fBservent\fP structure if the requested entry was found, and a null
pointer if the end of the database was reached or the
requested entry was not found. Otherwise, a null pointer is returned.
.SH ERRORS
.LP
No errors are defined.
.LP
\fIThe following sections are informative.\fP
.SH EXAMPLES
.LP
None.
.SH APPLICATION USAGE
.LP
The \fIport\fP argument of \fIgetservbyport\fP() need not be compatible
with the port values of all address families.
.LP
The \fIgetservbyname\fP(), \fIgetservbyport\fP(), and \fIgetservent\fP()
functions may return pointers to static data, which
may be overwritten by subsequent calls to any of these functions.
.SH RATIONALE
.LP
None.
.SH FUTURE DIRECTIONS
.LP
None.
.SH SEE ALSO
.LP
\fIendhostent\fP(), \fIendprotoent\fP(), \fIhtonl\fP(), \fIinet_addr\fP(),
the Base Definitions volume of
IEEE\ Std\ 1003.1-2001, \fI<netdb.h>\fP
.SH COPYRIGHT
Portions of this text are reprinted and reproduced in electronic form
from IEEE Std 1003.1, 2003 Edition, Standard for Information Technology
-- Portable Operating System Interface (POSIX), The Open Group Base
Specifications Issue 6, Copyright (C) 2001-2003 by the Institute of
Electrical and Electronics Engineers, Inc and The Open Group. In the
event of any discrepancy between this version and the original IEEE and
The Open Group Standard, the original IEEE and The Open Group Standard
is the referee document. The original Standard can be obtained online at
http://www.opengroup.org/unix/online.html .