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1 | .\" Copyright 1993 David Metcalfe (david@prism.demon.co.uk) |
2 | .\" | |
93015253 | 3 | .\" %%%LICENSE_START(VERBATIM) |
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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. | |
c13182ef | 12 | .\" |
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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14 | .\" manual page may be incorrect or out-of-date.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. | |
c13182ef | 20 | .\" |
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21 | .\" Formatted or processed versions of this manual, if unaccompanied by |
22 | .\" the source, must acknowledge the copyright and authors of this work. | |
4b72fb64 | 23 | .\" %%%LICENSE_END |
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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 19:19:11 1993 by Rik Faith (faith@cs.unc.edu) | |
30 | .\" Modified Wed Oct 18 20:23:54 1995 by Martin Schulze <joey@infodrom.north.de> | |
31 | .\" Modified Mon Apr 22 01:50:54 1996 by Martin Schulze <joey@infodrom.north.de> | |
32 | .\" 2001-07-25 added a clause about NULL proto (Martin Michlmayr or David N. Welton) | |
33 | .\" | |
4b8c67d9 | 34 | .TH GETSERVENT 3 2017-09-15 "GNU" "Linux Programmer's Manual" |
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35 | .SH NAME |
36 | getservent, getservbyname, getservbyport, setservent, endservent \- | |
c13182ef | 37 | get service entry |
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38 | .SH SYNOPSIS |
39 | .nf | |
40 | .B #include <netdb.h> | |
68e4db0a | 41 | .PP |
fea681da | 42 | .B struct servent *getservent(void); |
68e4db0a | 43 | .PP |
fea681da | 44 | .BI "struct servent *getservbyname(const char *" name ", const char *" proto ); |
68e4db0a | 45 | .PP |
fea681da | 46 | .BI "struct servent *getservbyport(int " port ", const char *" proto ); |
68e4db0a | 47 | .PP |
fea681da | 48 | .BI "void setservent(int " stayopen ); |
68e4db0a | 49 | .PP |
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50 | .B void endservent(void); |
51 | .fi | |
52 | .SH DESCRIPTION | |
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53 | The |
54 | .BR getservent () | |
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55 | function reads the next entry from the services database (see |
56 | .BR services (5)) | |
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57 | and returns a |
58 | .I servent | |
59 | structure containing | |
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60 | the broken-out fields from the entry. |
61 | A connection is opened to the database if necessary. | |
fea681da | 62 | .PP |
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63 | The |
64 | .BR getservbyname () | |
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65 | function returns a |
66 | .I servent | |
67 | structure | |
01089ed5 | 68 | for the entry from the database |
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69 | that matches the service |
70 | .I name | |
71 | using protocol | |
72 | .IR proto . | |
73 | If | |
74 | .I proto | |
75 | is NULL, any protocol will be matched. | |
01089ed5 | 76 | A connection is opened to the database if necessary. |
fea681da | 77 | .PP |
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78 | The |
79 | .BR getservbyport () | |
c6fa0841 MK |
80 | function returns a |
81 | .I servent | |
82 | structure | |
01089ed5 | 83 | for the entry from the database |
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84 | that matches the port |
85 | .I port | |
86 | (given in network byte order) | |
87 | using protocol | |
88 | .IR proto . | |
89 | If | |
90 | .I proto | |
91 | is NULL, any protocol will be matched. | |
01089ed5 | 92 | A connection is opened to the database if necessary. |
fea681da | 93 | .PP |
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94 | The |
95 | .BR setservent () | |
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96 | function opens a connection to the database, |
97 | and sets the next entry to the first entry. | |
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98 | If |
99 | .I stayopen | |
100 | is nonzero, | |
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101 | then the connection to the database |
102 | will not be closed between calls to one of the | |
103 | .BR getserv* () | |
104 | functions. | |
fea681da | 105 | .PP |
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106 | The |
107 | .BR endservent () | |
01089ed5 | 108 | function closes the connection to the database. |
fea681da | 109 | .PP |
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110 | The |
111 | .I servent | |
112 | structure is defined in | |
113 | .I <netdb.h> | |
114 | as follows: | |
51f5698d | 115 | .PP |
bd191423 | 116 | .in +4n |
b8302363 | 117 | .EX |
fea681da | 118 | struct servent { |
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119 | char *s_name; /* official service name */ |
120 | char **s_aliases; /* alias list */ | |
121 | int s_port; /* port number */ | |
122 | char *s_proto; /* protocol to use */ | |
fea681da | 123 | } |
b8302363 | 124 | .EE |
bd191423 | 125 | .in |
fea681da | 126 | .PP |
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127 | The members of the |
128 | .I servent | |
129 | structure are: | |
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130 | .TP |
131 | .I s_name | |
132 | The official name of the service. | |
133 | .TP | |
134 | .I s_aliases | |
01089ed5 | 135 | A NULL-terminated list of alternative names for the service. |
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136 | .TP |
137 | .I s_port | |
138 | The port number for the service given in network byte order. | |
139 | .TP | |
140 | .I s_proto | |
141 | The name of the protocol to use with this service. | |
47297adb | 142 | .SH RETURN VALUE |
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143 | The |
144 | .BR getservent (), | |
145 | .BR getservbyname () | |
146 | and | |
147 | .BR getservbyport () | |
23b21158 | 148 | functions return a pointer to a |
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149 | statically allocated |
150 | .I servent | |
b437fdd9 | 151 | structure, or NULL if an |
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152 | error occurs or the end of the file is reached. |
153 | .SH FILES | |
154 | .TP | |
155 | .I /etc/services | |
156 | services database file | |
9927122b ZL |
157 | .SH ATTRIBUTES |
158 | For an explanation of the terms used in this section, see | |
159 | .BR attributes (7). | |
160 | .TS | |
161 | allbox; | |
162 | lbw15 lb lbw25 | |
163 | l l l. | |
164 | Interface Attribute Value | |
165 | T{ | |
166 | .BR getservent () | |
167 | T} Thread safety T{ | |
168 | MT-Unsafe race:servent | |
169 | .br | |
170 | race:serventbuf locale | |
171 | T} | |
172 | T{ | |
173 | .BR getservbyname () | |
174 | T} Thread safety T{ | |
175 | MT-Unsafe race:servbyname | |
176 | .br | |
177 | locale | |
178 | T} | |
179 | T{ | |
180 | .BR getservbyport () | |
181 | T} Thread safety T{ | |
182 | MT-Unsafe race:servbyport | |
183 | .br | |
184 | locale | |
185 | T} | |
186 | T{ | |
187 | .BR setservent (), | |
188 | .br | |
189 | .BR endservent () | |
190 | T} Thread safety T{ | |
191 | MT-Unsafe race:servent | |
192 | .br | |
193 | locale | |
194 | T} | |
195 | .TE | |
847e0d88 | 196 | .sp 1 |
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197 | In the above table, |
198 | .I servent | |
199 | in | |
200 | .I race:servent | |
201 | signifies that if any of the functions | |
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202 | .BR setservent (), |
203 | .BR getservent (), | |
9927122b | 204 | or |
bf7bc8b8 | 205 | .BR endservent () |
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206 | are used in parallel in different threads of a program, |
207 | then data races could occur. | |
47297adb | 208 | .SH CONFORMING TO |
87292ccb | 209 | POSIX.1-2001, POSIX.1-2008, 4.3BSD. |
47297adb | 210 | .SH SEE ALSO |
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211 | .BR getnetent (3), |
212 | .BR getprotoent (3), | |
23b21158 | 213 | .BR getservent_r (3), |
fea681da | 214 | .BR services (5) |