1picocom(8) picocom(8)
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6 picocom - minimal dumb-terminal emulation program
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9 picocom [ options ] device
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12 As its name suggests, picocom is a minimal dumb-terminal emulation pro‐
13 gram. It is, in principle, very much like minicom(1) , only it's "pico"
14 instead of "mini"! It was designed to serve as a simple, manual, modem
15 configuration, testing, and debugging tool. It has also served (quite
16 well) as a low-tech "terminal-window" to allow operator intervention in
17 PPP connection scripts (something like the ms-windows "open terminal
18 window before / after dialing" feature). It could also prove useful in
19 many other similar tasks.
20 When picocom starts it opens the terminal (serial device) given as its
22 non-option argument. Unless the --noinit option is given, it configures
23 the device to the settings specified by the option-arguments (or to
24 some default settings), and sets it to "raw" mode. If --noinit is
25 given, the initialization and configuration is skipped; the device is
26 just opened. Following this, picocom sets the standard-input and stan‐
27 dard-output to raw mode. Having done so, it goes in a loop where it
28 listens for input from stdin, or from the serial port. Input from the
29 serial port is copied to the standard output while input from the stan‐
30 dard input is copied to the serial port. picocom also scans its input
31 stream for a user-specified control character, called the "escape char‐
32 acter" (being by default "C-a"). If the escape character is seen, then
33 instead of sending it to the serial-device, the program enters "command
34 mode" and waits for the next character (which is called the "function
35 character"). Depending on the value of the function character, picocom
36 performs one of the operations described in the "Commands" section
37 below.
38
41 Commands are given to picocom by first keying the "espace character"
42 which by default is "C-a" (see "Options" below on how to change it),
43 and then keying one for the function (command) characters shown here.
44 [escape character]
46 Send the escape character to the serial port and return to "trans‐
47 parent" mode. This means that if the escape character ("C-a", by
48 default) is typed twice, the program sends the escape character to
49 the serial port, and remains in transparent mode. This is a new
50 behavior implemented in v1.4. Previously picocom used to ignore the
51 escape-character when it was entered as a function character.
52 C-x
54 Exit the program: if the "--noreset" option was not given then the
55 serial port is reset to its original settings before exiting; if it
56 was given the serial port is not reset.
57 C-q
59 Quit the program *without* reseting the serial port, regardless of
60 the "--noreset" option.
61 C-p
63 Pulse the DTR line. Lower it for 1 sec, and then raise it again.
64 C-t
66 Toggle the DTR line. If DTR is up, then lower it. If it is down,
67 then raise it.
68 C-\
70 Generate a break sequence on the serial line. A break sequence is
71 usually generated by marking (driving to logical one) the serial Tx
72 line for an amount of time coresponding to several character dura‐
73 tions.
74 C-u
76 Baud up. Increase the baud-rate. The list of baud-rates stepped-
77 through by this command is: 300, 600, 1200, 2400, 4800, 9600, 19200,
78 38400, 57600, 115200.
79 C-d
81 Baud down. Decrease the baud-rate. The list of baud-rates stepped-
82 through by this command is the same as for the "baud-up" command.
83 C-f
85 Cycle through flow-control settings (RTS/CTS, XON/XOFF, none).
86 C-y
88 Cycle through parity settings (even, odd, none).
89 C-b
91 Cycle through databits-number settings (5, 6, 7, 8).
92 C-v
94 Show program options (like baud rate, data bits, etc). Only the
95 options that can be modified online (through commands) are shown,
96 not those that can only be set at the command-line.
97 C-s
99 Send (upload) a file (see "Sending and Receiving Files" below)
100 C-r
102 Receive (download) a file (see "Sending and Receiving Files" below)
103 After performing one of the above operations the program leaves the
105 command mode and enters transparent mode. Example: To increase the
106 baud-rate by two steps, you have to type:
107 C-a, C-u, C-a, C-u
109 assuming of-course that "C-a" is the escape character.
111
114 picocom can send and receive files over the serial port using external
115 programs that implement the respective protocols. In Linux typical pro‐
116 grams for this purpose are:
117 — rx(1) - receive using the X-MODEM protocol
119 — rb(1) - receive using the Y-MODEM protocol
121 — rz(1) - receive using the Z-MODEM protocol
123 — sx(1) - send using the X-MODEM protocol
125 — sb(1) - send using the Y-MODEM protocol
127 — sz(1) - send using the Z-MODEM protocol
129 — ascii-xfr(1) - receive or transmit ASCII files
131 The name of, and the command-line options to, the program to be used
133 for transmitting files are given by the "--send-cmd" option. Similarly
134 the program to receive files, and its argumets, are given by the
135 "--receive-cmd" option. For example, in order to start a picocom ses‐
136 sion that uses "sz" to transmit files, and "rz" to receive, you have to
137 say something like this:
138 picocom --send-cmd "sz -vv" --receive-cmd "rz -vv"
140 During the picocom session, if you key the "send" or "receive" commands
142 (e.g. by pressing C-a, C-s, or C-a, C-r) you will be prompted for a
143 filename. At this prompt you can enter one or more file-names, and any
144 additional arguments to the transmission or reception program. After
145 that, picocom will start the the external program as specified by the
146 "--send-cmd", or "--receive-cmd" option, and with any filenames and
147 additional arguments you may have supplied. The standard input and out‐
148 put of the external program will be connected to the serial port. The
149 standard error of the external program will be connected to the termi‐
150 nal which---while the program is running---will revert to canonical
151 mode. Pressing 'C-c' while the external program is running will prema‐
152 turely terminate it, and return control to picocom
153
156 picocom accepts the following command-line options
157 --baud | -b
159 Defines the baud-rate to set the serial-port (terminal) to.
160 --flow | -f
162 Defines the flow-control mode to set the serial-port to. Must be one
163 of:
164 — ´x' for xon/xoff (software) mode
166 — ´h' for hardware flow control (RTS/CTS)
168 — ´n' for no flow control
170 (Default: 'n')
172 --parity | -p
174 Defines the parity mode to set the serial-port to. Must be one of:
175 — ´o' for odd parity mode.
177 — ´e' for even parity mode.
179 — ´n' for no parity, mode.
181 (Default: 'n')
183 --databits | -d
185 Defines the number of data bits in every character. Must be one of:
186 5, 6, 7, 8
187 (Default: 8)
189 --esacpe | -e
191 Defines the character that will make picocom enter command-mode (see
192 description above). If 'x' is given, then C-x will make picocom
193 enter command mode.
194 (Default: 'a')
196 --noinit | -i
198 If given, picocom will not initialize, reset, or otherwise meddle
199 with the serial port at start-up. It will just open it. This is use‐
200 ful, for example, for connecting picocom to already-connected
201 modems, or already configured ports without terminating the connec‐
202 tion, or altering the settings. If required serial port parameters
203 can then be adjusted at run-time by commands.
204 --noreset | -r
206 If given, picocom will not *reset* the serial port when exiting. It
207 will just close the filedes and do nothing more. This is useful, for
208 example, for leaving modems connected when exiting picocom picocom
209 using the "Quit" command (instead of "Exit"), which never resets the
210 serial port. If "--noreset" is given then "Quit" and "Exit" behave
211 essentially the same.
212 --nolock | -l
214 If given, picocom will *not* attempt to lock the serial port before
215 opening it. Normally picocom attempts to get a UUCP-style lock-file
216 (e.g. "/var/lock/LCK..ttyS0") before opening the port. Failing to do
217 so, results in the program exiting after emitting an error-message.
218 It is possible that your picocom binary is compiled without this
219 option.
220 --send-cmd | -s
222 Specifies the external program (and any arguments to it) that will
223 be used for transmitting files.
224 Default: "sz -vv"
226 --receive-cmd | -v
228 Specifies the external program (and any arguments to it) that will
229 be used for receiving files.
230 (Default: "rz -vv")
232 --help | -h
234 Print a short help message describing the command-line options.
235
237 picocom was written by Nick Patavalis (npat@efault.net)
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241 The latest version of "picocom" can be downloaded from:
242 http://efault.net/npat/hacks/picocom/
243 picocom(8)