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1 | .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) | |
2 | .\" | |
3 | .\" %%%LICENSE_START(VERBATIM) | |
4 | .\" Permission is granted to make and distribute verbatim copies of this | |
5 | .\" manual provided the copyright notice and this permission notice are | |
6 | .\" preserved on all copies. | |
7 | .\" | |
8 | .\" Permission is granted to copy and distribute modified versions of this | |
9 | .\" manual under the conditions for verbatim copying, provided that the | |
10 | .\" entire resulting derived work is distributed under the terms of a | |
11 | .\" permission notice identical to this one. | |
12 | .\" | |
13 | .\" Since the Linux kernel and libraries are constantly changing, this | |
14 | .\" manual page may be incorrect or out-of-date. The author(s) assume no | |
15 | .\" responsibility for errors or omissions, or for damages resulting from | |
16 | .\" the use of the information contained herein. The author(s) may not | |
17 | .\" have taken the same level of care in the production of this manual, | |
18 | .\" which is licensed free of charge, as they might when working | |
19 | .\" professionally. | |
20 | .\" | |
21 | .\" Formatted or processed versions of this manual, if unaccompanied by | |
22 | .\" the source, must acknowledge the copyright and authors of this work. | |
23 | .\" %%%LICENSE_END | |
24 | .\" | |
25 | .\" References consulted: | |
26 | .\" Linux libc source code | |
27 | .\" Lewine's _POSIX Programmer's Guide_ (O'Reilly & Associates, 1991) | |
28 | .\" 386BSD man pages | |
29 | .\" Modified Sat Jul 24 19:26:03 1993 by Rik Faith (faith@cs.unc.edu) | |
30 | .TH GETPROTOENT 3 2017-09-15 "GNU" "Linux Programmer's Manual" | |
31 | .SH NAME | |
32 | getprotoent, getprotobyname, getprotobynumber, setprotoent, | |
33 | endprotoent \- get protocol entry | |
34 | .SH SYNOPSIS | |
35 | .nf | |
36 | .B #include <netdb.h> | |
37 | .PP | |
38 | .B struct protoent *getprotoent(void); | |
39 | .PP | |
40 | .BI "struct protoent *getprotobyname(const char *" name ); | |
41 | .PP | |
42 | .BI "struct protoent *getprotobynumber(int " proto ); | |
43 | .PP | |
44 | .BI "void setprotoent(int " stayopen ); | |
45 | .PP | |
46 | .B void endprotoent(void); | |
47 | .fi | |
48 | .SH DESCRIPTION | |
49 | The | |
50 | .BR getprotoent () | |
51 | function reads the next entry from the protocols database (see | |
52 | .BR protocols (5)) | |
53 | and returns a | |
54 | .I protoent | |
55 | structure | |
56 | containing the broken-out fields from the entry. | |
57 | A connection is opened to the database if necessary. | |
58 | .PP | |
59 | The | |
60 | .BR getprotobyname () | |
61 | function returns a | |
62 | .I protoent | |
63 | structure | |
64 | for the entry from the database | |
65 | that matches the protocol name | |
66 | .IR name . | |
67 | A connection is opened to the database if necessary. | |
68 | .PP | |
69 | The | |
70 | .BR getprotobynumber () | |
71 | function returns a | |
72 | .I protoent | |
73 | structure | |
74 | for the entry from the database | |
75 | that matches the protocol number | |
76 | .IR number . | |
77 | A connection is opened to the database if necessary. | |
78 | .PP | |
79 | The | |
80 | .BR setprotoent () | |
81 | function opens a connection to the database, | |
82 | and sets the next entry to the first entry. | |
83 | If | |
84 | .I stayopen | |
85 | is nonzero, | |
86 | then the connection to the database | |
87 | will not be closed between calls to one of the | |
88 | .BR getproto* () | |
89 | functions. | |
90 | .PP | |
91 | The | |
92 | .BR endprotoent () | |
93 | function closes the connection to the database. | |
94 | .PP | |
95 | The | |
96 | .I protoent | |
97 | structure is defined in | |
98 | .I <netdb.h> | |
99 | as follows: | |
100 | .PP | |
101 | .in +4n | |
102 | .EX | |
103 | struct protoent { | |
104 | char *p_name; /* official protocol name */ | |
105 | char **p_aliases; /* alias list */ | |
106 | int p_proto; /* protocol number */ | |
107 | } | |
108 | .EE | |
109 | .in | |
110 | .PP | |
111 | The members of the | |
112 | .I protoent | |
113 | structure are: | |
114 | .TP | |
115 | .I p_name | |
116 | The official name of the protocol. | |
117 | .TP | |
118 | .I p_aliases | |
119 | A NULL-terminated list of alternative names for the protocol. | |
120 | .TP | |
121 | .I p_proto | |
122 | The protocol number. | |
123 | .SH RETURN VALUE | |
124 | The | |
125 | .BR getprotoent (), | |
126 | .BR getprotobyname () | |
127 | and | |
128 | .BR getprotobynumber () | |
129 | functions return a pointer to a | |
130 | statically allocated | |
131 | .I protoent | |
132 | structure, or a null pointer if an | |
133 | error occurs or the end of the file is reached. | |
134 | .SH FILES | |
135 | .PD 0 | |
136 | .TP | |
137 | .I /etc/protocols | |
138 | protocol database file | |
139 | .PD | |
140 | .SH ATTRIBUTES | |
141 | For an explanation of the terms used in this section, see | |
142 | .BR attributes (7). | |
143 | .TS | |
144 | allbox; | |
145 | lbw18 lb lbw28 | |
146 | l l l. | |
147 | Interface Attribute Value | |
148 | T{ | |
149 | .BR getprotoent () | |
150 | T} Thread safety T{ | |
151 | MT-Unsafe race:protoent | |
152 | .br | |
153 | race:protoentbuf locale | |
154 | T} | |
155 | T{ | |
156 | .BR getprotobyname () | |
157 | T} Thread safety T{ | |
158 | MT-Unsafe race:protobyname | |
159 | .br | |
160 | locale | |
161 | T} | |
162 | T{ | |
163 | .BR getprotobynumber () | |
164 | T} Thread safety T{ | |
165 | MT-Unsafe race:protobynumber | |
166 | .br | |
167 | locale | |
168 | T} | |
169 | T{ | |
170 | .BR setprotoent (), | |
171 | .br | |
172 | .BR endprotoent () | |
173 | T} Thread safety T{ | |
174 | MT-Unsafe race:protoent | |
175 | .br | |
176 | locale | |
177 | T} | |
178 | .TE | |
179 | .sp 1 | |
180 | In the above table, | |
181 | .I protoent | |
182 | in | |
183 | .I race:protoent | |
184 | signifies that if any of the functions | |
185 | .BR setprotoent (), | |
186 | .BR getprotoent (), | |
187 | or | |
188 | .BR endprotoent () | |
189 | are used in parallel in different threads of a program, | |
190 | then data races could occur. | |
191 | .SH CONFORMING TO | |
192 | POSIX.1-2001, POSIX.1-2008, 4.3BSD. | |
193 | .SH SEE ALSO | |
194 | .BR getnetent (3), | |
195 | .BR getprotoent_r (3), | |
196 | .BR getservent (3), | |
197 | .BR protocols (5) |