1ENDSERVENT(3P) POSIX Programmer's Manual ENDSERVENT(3P)
2
6 This manual page is part of the POSIX Programmer's Manual. The Linux
7 implementation of this interface may differ (consult the corresponding
8 Linux manual page for details of Linux behavior), or the interface may
9 not be implemented on Linux.
10
13 endservent, getservbyname, getservbyport, getservent, setservent — net‐
14 work services database functions
15
17 #include <netdb.h>
18 void endservent(void);
20 struct servent *getservbyname(const char *name, const char *proto);
21 struct servent *getservbyport(int port, const char *proto);
22 struct servent *getservent(void);
23 void setservent(int stayopen);
24
26 These functions shall retrieve information about network services. This
27 information is considered to be stored in a database that can be
28 accessed sequentially or randomly. The implementation of this database
29 is unspecified.
30 The setservent() function shall open a connection to the database, and
32 set the next entry to the first entry. If the stayopen argument is non-
33 zero, the net database shall not be closed after each call to the get‐
34 servent() function (either directly, or indirectly through one of the
35 other getserv*() functions), and the implementation may maintain an
36 open file descriptor for the database.
37 The getservent() function shall read the next entry of the database,
39 opening and closing a connection to the database as necessary.
40 The getservbyname() function shall search the database from the begin‐
42 ning and find the first entry for which the service name specified by
43 name matches the s_name member and the protocol name specified by proto
44 matches the s_proto member, opening and closing a connection to the
45 database as necessary. If proto is a null pointer, any value of the
46 s_proto member shall be matched.
47 The getservbyport() function shall search the database from the begin‐
49 ning and find the first entry for which the port specified by port
50 matches the s_port member and the protocol name specified by proto
51 matches the s_proto member, opening and closing a connection to the
52 database as necessary. If proto is a null pointer, any value of the
53 s_proto member shall be matched. The port argument shall be a value
54 obtained by converting a uint16_t in network byte order to int.
55 The getservbyname(), getservbyport(), and getservent() functions shall
57 each return a pointer to a servent structure, the members of which
58 shall contain the fields of an entry in the network services database.
59 The endservent() function shall close the database, releasing any open
61 file descriptor.
62 These functions need not be thread-safe.
64
66 Upon successful completion, getservbyname(), getservbyport(), and get‐
67 servent() return a pointer to a servent structure if the requested
68 entry was found, and a null pointer if the end of the database was
69 reached or the requested entry was not found. Otherwise, a null
70 pointer is returned.
71 The application shall not modify the structure to which the return
73 value points, nor any storage areas pointed to by pointers within the
74 structure. The returned pointer, and pointers within the structure,
75 might be invalidated or the structure or the storage areas might be
76 overwritten by a subsequent call to getservbyname(), getservbyport(),
77 or getservent().
78
80 No errors are defined.
81 The following sections are informative.
83
85 None.
86
88 The port argument of getservbyport() need not be compatible with the
89 port values of all address families.
90
92 None.
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95 None.
96
98 endhostent(), endprotoent(), htonl(), inet_addr()
99 The Base Definitions volume of POSIX.1‐2008, <netdb.h>
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103 Portions of this text are reprinted and reproduced in electronic form
104 from IEEE Std 1003.1, 2013 Edition, Standard for Information Technology
105 -- Portable Operating System Interface (POSIX), The Open Group Base
106 Specifications Issue 7, Copyright (C) 2013 by the Institute of Electri‐
107 cal and Electronics Engineers, Inc and The Open Group. (This is
108 POSIX.1-2008 with the 2013 Technical Corrigendum 1 applied.) In the
109 event of any discrepancy between this version and the original IEEE and
110 The Open Group Standard, the original IEEE and The Open Group Standard
111 is the referee document. The original Standard can be obtained online
112 at http://www.unix.org/online.html .
113 Any typographical or formatting errors that appear in this page are
115 most likely to have been introduced during the conversion of the source
116 files to man page format. To report such errors, see https://www.ker‐
117 nel.org/doc/man-pages/reporting_bugs.html .
118IEEE/The Open Group 2013 ENDSERVENT(3P)