1.\" $OpenBSD: cu.1,v 1.3 2006/06/07 06:35:59 mbalmer Exp $ 2.\" 3.\" Copyright (c) 1980, 1990, 1993 4.\" The Regents of the University of California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that the following conditions 8.\" are met: 9.\" 1. Redistributions of source code must retain the above copyright 10.\" notice, this list of conditions and the following disclaimer. 11.\" 2. Redistributions in binary form must reproduce the above copyright 12.\" notice, this list of conditions and the following disclaimer in the 13.\" documentation and/or other materials provided with the distribution. 14.\" 3. Neither the name of the University nor the names of its contributors 15.\" may be used to endorse or promote products derived from this software 16.\" without specific prior written permission. 17.\" 18.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28.\" SUCH DAMAGE. 29.\" 30.\" @(#)tip.1 8.4 (Berkeley) 4/18/94 31.\" $FreeBSD$ 32.\" 33.Dd April 22, 2017 34.Dt CU 1 35.Os 36.Sh NAME 37.Nm cu 38.Nd call UNIX 39.Sh SYNOPSIS 40.Nm 41.Op Fl ehot 42.Op Fl a Ar acu 43.Op Fl l Ar line 44.Op Fl s Ar speed | Fl Ar speed 45.Op Ar phone-number 46.Sh DESCRIPTION 47The 48.Nm 49utility 50establishes a full-duplex connection to another machine, giving the 51appearance of being logged in directly on the remote CPU. 52It goes without saying that you must have a login on the machine (or 53equivalent) to which you wish to connect. 54.Pp 55The options are as follows: 56.Bl -tag -width indent 57.It Fl a Ar acu 58Set the acu. 59.It Fl e 60Use even parity. 61If both 62.Fl e 63and 64.Fl o 65are given, then no parity is used 66(the default). 67.It Fl h 68Echo characters locally (half-duplex mode). 69.It Fl l Ar line 70Specify the line to use. 71Either of the forms like 72.Pa cuau0 73or 74.Pa /dev/cuau0 75are permitted. 76.It Fl o 77Use odd parity. 78If both 79.Fl e 80and 81.Fl o 82are given, then no parity is used 83(the default). 84.It Fl s Ar speed | Fl Ar speed 85Set the speed of the connection. 86The default is 9600. 87.It Fl t 88Connect via a hard-wired connection to a host on a dial-up line. 89.El 90.Pp 91Typed characters are normally transmitted directly to the remote 92machine (which does the echoing as well). 93A tilde 94.Pq Ql ~ 95appearing as the first character of a line is an escape signal; the 96following are recognized: 97.Bl -tag -width indent 98.It Ic ~^D No or Ic ~. 99Drop the connection and exit. 100Only the connection is dropped \(en the login session is not terminated. 101.It Ic ~c Op Ar name 102Change directory to 103.Ar name 104(no argument implies change to home directory). 105.It Ic ~! 106Escape to a shell (exiting the shell will return to 107.Nm ) . 108.It Ic ~> 109Copy file from local to remote. 110The 111.Nm 112utility 113prompts for the name of a local file to transmit. 114.It Ic ~< 115Copy file from remote to local. 116The 117.Nm 118utility 119prompts first for the name of the file to be sent, then for a command 120to be executed on the remote machine. 121.It Ic ~p Ar from Op Ar to 122Send a file to a remote 123.Ux 124host. 125This command causes the remote 126.Ux 127system to run the following command string, 128sending it the 129.Ar from 130file: 131.Pp 132.Dl "stty -echo; cat > 'to'; stty echo" 133.Pp 134If the 135.Ar to 136file is not specified, the 137.Ar from 138file name is used. 139This command is actually a 140.Ux 141specific version of the 142.Ic ~> 143command. 144.It Ic ~t Ar from Op Ar to 145Take a file from a remote 146.Ux 147host. 148As in the 149.Ic ~p 150command, the 151.Ar to 152file defaults to the 153.Ar from 154file name if it is not specified. 155The remote host executes the following command string 156to send the file to 157.Nm : 158.Pp 159.Dl "cat 'from'; echo '' | tr '\e012' '\e01'" 160.It Ic ~| 161Pipe the output from a remote command to a local 162.Ux 163process. 164The command string sent to the local 165.Ux 166system is processed by the shell. 167.It Ic ~$ 168Pipe the output from a local 169.Ux 170process to the remote host. 171The command string sent to the local 172.Ux 173system is processed by the shell. 174.It Ic ~C 175Fork a child process on the local system to perform special protocols 176such as 177.Tn XMODEM . 178The child program will be run with the following arrangement of 179file descriptors: 180.Bd -literal -offset indent 1810 <-> remote tty in 1821 <-> remote tty out 1832 <-> local tty stderr 184.Ed 185.It Ic ~# 186Send a 187.Dv BREAK 188to the remote system. 189For systems which do not support the necessary 190.Fn ioctl 191call, the break is simulated by a sequence of line speed changes and 192.Dv DEL 193characters. 194.It Ic ~s 195Set a variable (see the discussion below). 196.It Ic ~v 197List all variables and their values (if set). 198.It Ic ~^Z 199Stop 200.Nm 201(only available with job control). 202.It Ic ~^Y 203Stop only the 204.Dq "local side" 205of 206.Nm 207(only available with job control); the 208.Dq "remote side" 209of 210.Nm , 211the side that displays output from the remote host, is left running. 212.It Ic ~? 213Get a summary of the tilde escapes. 214.El 215.Pp 216When 217.Nm 218prompts for an argument, for example during setup of a file transfer, the 219line typed may be edited with the standard erase and kill characters. 220A null line in response to a prompt, or an interrupt, will abort the 221dialogue and return the user to the remote machine. 222.Pp 223The 224.Nm 225utility 226guards against multiple users connecting to a remote system by opening 227modems and terminal lines with exclusive access, and by honoring the 228locking protocol used by 229.Xr uucico 8 Pq Pa ports/net/freebsd-uucp . 230.Pp 231During file transfers 232.Nm 233provides a running count of the number of lines transferred. 234When using the 235.Ic ~> 236and 237.Ic ~< 238commands, the 239.Va eofread 240and 241.Va eofwrite 242variables are used to recognize end-of-file when reading, and specify 243end-of-file when writing (see below). 244File transfers normally depend on hardwareflow or tandem mode for flow control. 245If the remote system does not support hardwareflow or tandem mode, 246.Va echocheck 247may be set to indicate that 248.Nm 249should synchronize with the remote system on the echo of each 250transmitted character. 251.Pp 252When 253.Nm 254must dial a phone number to connect to a system, it will print various 255messages indicating its actions. 256The 257.Nm 258utility 259supports a variety of auto-call units and modems with the 260.Va at 261capability in system descriptions. 262.Pp 263Support for Ventel 212+ (ventel), Hayes AT-style (hayes), 264USRobotics Courier (courier), Telebit T3000 (t3000) and 265Racal-Vadic 831 (vadic) units is enabled by default. 266.Pp 267Support for Bizcomp 1031[fw] (biz31[fw]), Bizcomp 1022[fw] 268(biz22[fw]), DEC DF0[23]-AC (df0[23]), DEC DN-11 (dn11) and 269Racal-Vadic 3451 (v3451) units can be added by recompiling 270.Nm 271with the appropriate defines. 272.Pp 273Note that if support for both the Racal-Vadic 831 and 3451 is enabled, 274they are referred to as the v831 and v3451, respectively. 275If only one of the two is supported, it is referred to as vadic. 276.Ss Variables 277The 278.Nm 279utility 280maintains a set of variables which control its operation. 281Some of these variables are read-only to normal users (root is allowed 282to change anything of interest). 283Variables may be displayed and set through the 284.Ic ~s 285escape. 286The syntax for variables is patterned after 287.Xr vi 1 288and 289.Xr Mail 1 . 290Supplying 291.Dq Li all 292as an argument to the set command displays all variables readable by 293the user. 294Alternatively, the user may request display of a particular variable 295by attaching a 296.Ql \&? 297to the end. 298For example, 299.Dq Li escape? 300displays the current escape character. 301.Pp 302Variables are numeric, string, character, or boolean values. 303Boolean variables are set merely by specifying their name; they may be 304reset by prepending a 305.Ql \&! 306to the name. 307Other variable types are set by concatenating an 308.Ql = 309and the value. 310The entire assignment must not have any blanks in it. 311A single set command may be used to interrogate as well as set a 312number of variables. 313Certain common variables have abbreviations. 314The following is a list of common variables, their abbreviations, and 315their default values: 316.Bl -tag -width indent 317.It Va baudrate 318.Pq Vt num 319The baud rate at which the connection was established; 320abbreviated 321.Va ba . 322.It Va beautify 323.Pq Vt bool 324Discard unprintable characters when a session is being 325scripted; abbreviated 326.Va be . 327.It Va dialtimeout 328.Pq Vt num 329When dialing a phone number, the time (in seconds) to wait for a 330connection to be established; abbreviated 331.Va dial . 332.It Va echocheck 333.Pq Vt bool 334Synchronize with the remote host during file transfer by 335waiting for the echo of the last character transmitted; default is 336.Cm off . 337.It Va eofread 338.Pq Vt str 339The set of characters which signify an end-of-transmission 340during a 341.Ic ~< 342file transfer command; abbreviated 343.Va eofr . 344.It Va eofwrite 345.Pq Vt str 346The string sent to indicate end-of-transmission during a 347.Ic ~> 348file transfer command; abbreviated 349.Va eofw . 350.It Va eol 351.Pq Vt str 352The set of characters which indicate an end-of-line. 353The 354.Nm 355utility 356will recognize escape characters only after an end-of-line. 357.It Va escape 358.Pq Vt char 359The command prefix (escape) character; abbreviated 360.Va es ; 361default value is 362.Ql ~ . 363.It Va exceptions 364.Pq Vt str 365The set of characters which should not be discarded due to the 366beautification switch; abbreviated 367.Va ex ; 368default value is 369.Dq Li \et\en\ef\eb . 370.It Va force 371.Pq Vt char 372The character used to force literal data transmission; 373abbreviated 374.Va fo ; 375default value is 376.Ql ^P . 377.It Va framesize 378.Pq Vt num 379The amount of data (in bytes) to buffer between file system 380writes when receiving files; abbreviated 381.Va fr . 382.It Va hardwareflow 383.Pq Vt bool 384Whether hardware flow control (CRTSCTS) is enabled for the 385connection; abbreviated 386.Va hf ; 387default value is 388.Cm off . 389.It Va host 390.Pq Vt str 391The name of the host to which you are connected; abbreviated 392.Va ho . 393.It Va linedisc 394.Pq Vt num 395The line discipline to use; abbreviated 396.Va ld . 397.It Va prompt 398.Pq Vt char 399The character which indicates an end-of-line on the remote 400host; abbreviated 401.Va pr ; 402default value is 403.Ql \en . 404This value is used to synchronize during data transfers. 405The count of lines transferred during a file transfer command is based 406on receipt of this character. 407.It Va raise 408.Pq Vt bool 409Upper case mapping mode; abbreviated 410.Va ra ; 411default value is 412.Cm off . 413When this mode is enabled, all lowercase letters will be mapped to 414uppercase by 415.Nm 416for transmission to the remote machine. 417.It Va raisechar 418.Pq Vt char 419The input character used to toggle uppercase mapping mode; 420abbreviated 421.Va rc ; 422not set by default. 423.It Va record 424.Pq Vt str 425The name of the file in which a session script is recorded; 426abbreviated 427.Va rec . 428.It Va script 429.Pq Vt bool 430Session scripting mode; abbreviated 431.Va sc ; 432default is 433.Cm off . 434When 435.Va script 436is 437.Cm true , 438.Nm 439will record everything transmitted by the remote machine in the script 440record file specified in 441.Va record . 442If the 443.Va beautify 444switch is on, only printable 445.Tn ASCII 446characters will be included in the script file (those characters 447between 040 and 0177). 448The variable 449.Va exceptions 450is used to indicate characters which are an exception to the normal 451beautification rules. 452.It Va tabexpand 453.Pq Vt bool 454Expand tabs to spaces during file transfers; abbreviated 455.Va tab ; 456default value is 457.Cm false . 458Each tab is expanded to 8 spaces. 459.It Va tandem 460.Pq Vt bool 461Use XON/XOFF flow control to throttle data from the remote host; 462abbreviated 463.Va ta . 464The default value is 465.Cm true . 466.It Va verbose 467.Pq Vt bool 468Verbose mode; abbreviated 469.Va verb ; 470default is 471.Cm true . 472When verbose mode is enabled, 473.Nm 474prints messages while dialing, shows the current number of lines 475transferred during a file transfer operations, and more. 476.El 477.Sh ENVIRONMENT 478.Bl -tag -width indent 479.It Ev HOME 480The home directory to use for the 481.Ic ~c 482command. 483.It Ev SHELL 484The name of the shell to use for the 485.Ic ~! 486command; default value is 487.Dq Li /bin/sh . 488.El 489.Sh FILES 490.Bl -tag -width ".Pa /var/spool/lock/LCK..*" -compact 491.It Pa /var/log/aculog 492line access log 493.It Pa /var/spool/lock/LCK..* 494lock file to avoid conflicts with 495.Xr uucp 1 Pq Pa ports/net/freebsd-uucp 496.El 497.Sh EXAMPLES 498Connect to the first USB serial port at the speed of 115200 baud: 499.Bd -literal -offset indent 500cu -s 115200 -l /dev/cuaU0 501.Ed 502.Sh SEE ALSO 503.Xr tip 1 504.Sh HISTORY 505The 506.Nm 507command appeared in 508.Bx 4.2 . 509.Sh BUGS 510The full set of variables is undocumented and should, probably, be 511pared down. 512