mirror of https://github.com/mkerrisk/man-pages
131 lines
3.9 KiB
Groff
131 lines
3.9 KiB
Groff
.\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk)
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.\"
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.\" Permission is granted to make and distribute verbatim copies of this
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.\" manual provided the copyright notice and this permission notice are
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.\" preserved on all copies.
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.\"
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.\" Permission is granted to copy and distribute modified versions of this
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.\" manual under the conditions for verbatim copying, provided that the
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.\" entire resulting derived work is distributed under the terms of a
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.\" permission notice identical to this one.
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.\"
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.\" Since the Linux kernel and libraries are constantly changing, this
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.\" manual page may be incorrect or out-of-date. The author(s) assume no
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.\" responsibility for errors or omissions, or for damages resulting from
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.\" the use of the information contained herein. The author(s) may not
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.\" have taken the same level of care in the production of this manual,
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.\" which is licensed free of charge, as they might when working
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.\" professionally.
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.\"
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.\" Formatted or processed versions of this manual, if unaccompanied by
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.\" the source, must acknowledge the copyright and authors of this work.
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.\"
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.\" References consulted:
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.\" Linux libc source code
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.\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991)
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.\" 386BSD man pages
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.\" Modified Sat Jul 24 19:19:11 1993 by Rik Faith (faith@cs.unc.edu)
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.\" Modified Wed Oct 18 20:23:54 1995 by Martin Schulze <joey@infodrom.north.de>
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.\" Modified Mon Apr 22 01:50:54 1996 by Martin Schulze <joey@infodrom.north.de>
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.\" 2001-07-25 added a clause about NULL proto (Martin Michlmayr or David N. Welton)
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.\"
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.TH GETSERVENT 3 2001-07-25 "GNU" "Linux Programmer's Manual"
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.SH NAME
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getservent, getservbyname, getservbyport, setservent, endservent \-
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get service entry
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.SH SYNOPSIS
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.nf
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.B #include <netdb.h>
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.sp
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.B struct servent *getservent(void);
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.sp
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.BI "struct servent *getservbyname(const char *" name ", const char *" proto );
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.sp
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.BI "struct servent *getservbyport(int " port ", const char *" proto );
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.sp
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.BI "void setservent(int " stayopen );
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.sp
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.B void endservent(void);
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.fi
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.SH DESCRIPTION
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The
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.BR getservent ()
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function reads the next line from the file
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\fI/etc/services\fP and returns a structure \fIservent\fP containing
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the broken out fields from the line.
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The \fI/etc/services\fP file
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is opened if necessary.
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.PP
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The
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.BR getservbyname ()
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function returns a \fIservent\fP structure
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for the line from \fI/etc/services\fP that matches the service
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\fIname\fP using protocol \fIproto\fP.
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If \fIproto\fP is NULL, any protocol will be matched.
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.PP
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The
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.BR getservbyport ()
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function returns a \fIservent\fP structure
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for the line that matches the port \fIport\fP given in network byte order
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using protocol \fIproto\fP.
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If \fIproto\fP is NULL, any protocol will be matched.
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.PP
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The
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.BR setservent ()
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function opens and rewinds the
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\fI/etc/services\fP file.
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If \fIstayopen\fP is true (1), then the
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file will not be closed between calls to
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.BR getservbyname ()
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and
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.BR getservbyport ().
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.PP
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The
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.BR endservent ()
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function closes \fI/etc/services\fP.
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.PP
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The \fIservent\fP structure is defined in \fI<netdb.h>\fP as follows:
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.sp
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.in +4n
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.nf
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struct servent {
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char *s_name; /* official service name */
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char **s_aliases; /* alias list */
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int s_port; /* port number */
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char *s_proto; /* protocol to use */
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}
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.fi
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.in
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.PP
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The members of the \fIservent\fP structure are:
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.TP
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.I s_name
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The official name of the service.
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.TP
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.I s_aliases
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A zero terminated list of alternative names for the service.
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.TP
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.I s_port
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The port number for the service given in network byte order.
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.TP
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.I s_proto
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The name of the protocol to use with this service.
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.SH "RETURN VALUE"
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The
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.BR getservent (),
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.BR getservbyname ()
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and
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.BR getservbyport ()
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functions return the \fIservent\fP structure, or a NULL pointer if an
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error occurs or the end of the file is reached.
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.SH FILES
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.TP
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.I /etc/services
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services database file
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.SH "CONFORMING TO"
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4.3BSD, POSIX.1-2001.
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.SH "SEE ALSO"
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.BR getnetent (3),
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.BR getprotoent (3),
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.BR services (5)
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