1COAP-CLIENT(5) coap-client Manual COAP-CLIENT(5)
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6 coap-client - CoAP Client based on libcoap
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9 coap-client [-a addr] [-b [num,]size] [-e text] [-f file] [-l loss] [-m
10 method] [-o file] [-p port] [-r] [-s duration] [-t type] [-v num] [-A
11 type] [-B seconds] [-K interval] [-N] [-O num,text] [-P addr[:port]]
12 [-T token] [-U] [[-k key] [-u user]] [[-c certfile] [-C cafile] [-R
13 root_cafile]] URI
14
16 coap-client is a CoAP client to communicate with 6LoWPAN devices via
17 the protocol CoAP (RFC 7252) using the URI given as argument on the
18 command line. The URI must have the scheme coap, coap+tcp, coaps or
19 coaps+tcp. coaps and coaps+tcp are only supported when coap-client is
20 built with support for secure (D)TLS communication.
21 If coaps or coap+tcp is being used, provided the CoAP server supports
23 PKI and is configured with a Certificate and Private Key, the
24 coap-client does not need to have a Pre-Shared Key (-k) or Certificate
25 (-c) configured.
26 The URI’s host part may be a DNS name or a literal IP address. Note
28 that, for IPv6 address references, angle brackets are required (c.f.
29 EXAMPLES).
30
32 -a addr
33 The local address of the interface that has to be used.
34 -b [num,]size
36 The block size to be used in GET/PUT/POST requests (value must be a
37 multiple of 16 not larger than 1024 as libcoap uses a fixed maximum
38 PDU size of 1400 bytes). If num is present, the request chain will
39 start at block num. When the server includes a Block2 option in its
40 response to a GET request, coap-client will automatically retrieve
41 the subsequent block from the server until there are no more
42 outstanding blocks for the requested content.
43 -e text
45 Include text as payload (use percent-encoding for non-ASCII
46 characters).
47 -f file
49 File to send with PUT/POST (use - for STDIN).
50 -l list
52 Fail to send some datagrams specified by a comma separated list of
53 numbers or number ranges (debugging only).
54 -l loss%
56 Randomly failed to send datagams with the specified probability -
57 100% all datagrams, 0% no datagrams (debugging only).
58 -m method
60 The request method for action (get|put|post|delete), default is
61 get. (Note that the string passed to -m is compared
62 case-insensitive.)
63 -o file
65 A filename to store data retrieved with GET.
66 -p port
68 The port to listen on.
69 -r
71 Use reliable protocol (TCP or TLS).
72 -s duration
74 Subscribe to / observe the resource specified by URI for the given
75 duration in seconds.
76 -t type
78 Content format for given resource for PUT/POST. type must be
79 either a numeric value reflecting a valid CoAP content format or a
80 string describing a registered format. The following registered
81 content format descriptors are supported, with alternative
82 shortcuts given in parentheses:
83 text/plain (plain)
85 application/link-format (link, link-format)
86 application/xml (xml)
87 application/octet-stream (binary, octet-stream)
88 application/exi (exi)
89 application/json (json)
90 application/cbor (cbor)
91 -v num
93 The verbosity level to use (default 3, maximum is 9). Above 7,
94 there is increased verbosity in GnuTLS logging.
95 -A type
97 Accepted media type. type must be either a numeric value
98 reflecting a valid CoAP content format or a string that specifies a
99 registered format as described for option -t.
100 -B seconds
102 Break operation after waiting given seconds (default is 90).
103 -K interval
105 Send a ping after interval seconds of inactivity (TCP only). If not
106 specified, keep-alive is disabled (default).
107 -N
109 Send NON-confirmable message. If option -N is not specified, a
110 confirmable message will be sent.
111 -O num,text
113 Add option num with contents of text to the request.
114 -P addr[:port]
116 Address (and port) for proxy to use (automatically adds Proxy-Uri
117 option to request).
118 -T token
120 Include the token to the request.
121 -U
123 Never include Uri-Host or Uri-Port options.
124
126 (If supported by underlying (D)TLS library)
127 -k key
129 Pre-shared key for the specified user (-u option also required).
130 -u user
132 User identity for pre-shared key mode (-k option also required).
133
135 (If supported by underlying (D)TLS library)
136 -c certfile
138 Use the specified PEM file which contains the CERTIFICATE and
139 PRIVATE KEY information.
140 -C cafile
142 PEM file containing the CA Certificate that was used to sign the
143 certfile defined using -c certfile. This will trigger the
144 validation of the server certificate. If certfile is self-signed
145 (as defined by -c certfile), then you need to have on the command
146 line the same filename for both the certfile and cafile (as in -c
147 certfile -C certfile) to trigger validation.
148 -R root_cafile
150 PEM file containing the set of trusted root CAs that are to be used
151 to validate the server certificate. The -C cafile does not have to
152 be in this list and is "trusted" for the verification.
153 Alternatively, this can point to a directory containing a set of CA
154 PEM files.
155
157 · Example
158 coap-client coap://coap.me
160 Query the resource / from server coap.me (using the GET method).
162 · Example
164 coap-client -m get coap://[::1]/
166 Query the resource / on localhost using the GET method to get back the
168 summary defined attributes.
169 · Example
171 coap-client -m get coap://[::1]/.well-known/core
173 Query on the resource .well-known/core on localhost to get back a list
175 of the known resources along with their attribute definitions.
176 · Example
178 echo -n "mode=on" | coap-client -m put \
180 coap://[2001:db8:c001:f00d:221:2eff:ff00:2704]:5683/actuators/leds?color=r -f-
181 Send text mode=on to resource actuators/leds?color=r on the endpoint
183 with address 2001:db8:c001:f00d:221:2eff:ff00:2704 and port 5683. Note
184 that the port 5683 is the default port and isn’t actually required in
185 this instance.
186 · Example
188 coap-client -m put coap://[fec0::3]/ck -T 3a -t binary -f to_upload
190 Put the contents of file to_upload with content type binary (i.e.
192 application/octet-stream) into resource ck on fec0::3 using a token of
193 3a via the PUT method.
194
196 There are no configuration files.
197
199 0
200 Success
201 1
203 Failure (syntax or usage error; configuration error; document
204 processing failure; unexpected error)
205
207 Please report bugs on the mailing list for libcoap:
208 libcoap-developers@lists.sourceforge.net
209
211 The libcoap project <libcoap-developers@lists.sourceforge.net>
212coap-client 4.2.0 07/25/2019 COAP-CLIENT(5)