2 .\" manual page [] for chat 1.8
5 .\" SS subsection heading
7 .\" IP indented paragraph
9 .TH CHAT 8 "27 Sep 1997" "Chat Version 1.17"
11 chat \- Automated conversational script with a modem
20 The \fIchat\fR program defines a conversational exchange between the
21 computer and the modem.
22 Its primary purpose is to establish the
23 connection between the Point-to-Point Protocol Daemon (\fIpppd\fR) and
24 the remote's \fIpppd\fR process.
28 Read the chat script from the chat \fIfile\fR.
29 The use of this option
30 is mutually exclusive with the chat script parameters.
32 have read access to the file.
33 Multiple lines are permitted in the
35 Space or horizontal tab characters should be used to separate
39 Set the timeout for the expected string to be received.
41 is not received within the time limit then the reply string is not
43 An alternate reply may be sent or the script will fail if there
44 is no alternate reply string.
45 A failed script will cause the
46 \fIchat\fR program to terminate with a non-zero error code.
48 .B -r \fI<report file>
49 Set the file for output of the report strings.
50 If you use the keyword
51 \fIREPORT\fR, the resulting strings are written to this file.
53 option is not used and you still use \fIREPORT\fR keywords, the
54 \fIstderr\fR file is used for the report strings.
57 Start with the echo option turned on.
58 Echoing may also be turned on
59 or off at specific points in the chat script by using the \fIECHO\fR
61 When echoing is enabled, all output from the modem is echoed
65 Request that the \fIchat\fR script be executed in a verbose mode.
67 \fIchat\fR program will then log the execution state of the chat
68 script as well as all text received from the modem and the output
69 strings sent to the modem. The default is to log through
71 the logging method may be altered with the -S and -s flags.
73 done to the \fIlocal2\fR facility at level \fIinfo\fR for verbose tracing
74 and level \fIerr\fR for some errors.
77 Request that the \fIchat\fR script be executed in a stderr verbose
79 The \fIchat\fR program will then log all text received from the
80 modem and the output strings sent to the modem to the stderr device.
82 device is usually the local console at the station running the chat or
86 Use stderr. All log messages from '-v' and all error messages will be
92 By default, error messages are sent to
94 The use of -S will prevent both log messages from '-v' and
95 error messages from being sent to
98 .B -T \fI<phone number>
99 Pass in an arbitrary string, usually a phone number, that will be
100 substituted for the \\T substitution metacharacter in a send string.
102 .B -U \fI<phone number 2>
103 Pass in a second string, usually a phone number, that will be
104 substituted for the \\U substitution metacharacter in a send string.
105 This is useful when dialing an ISDN terminal adapter that requires two
109 If the script is not specified in a file with the \fI-f\fR option then
110 the script is included as parameters to the \fIchat\fR program.
113 The \fIchat\fR script defines the communications.
115 A script consists of one or more "expect-send" pairs of strings,
116 separated by spaces, with an optional "subexpect-subsend" string pair,
117 separated by a dash as in the following example:
119 ogin:-BREAK-ogin: ppp ssword: hello2u2
121 This line indicates that the \fIchat\fR program should expect the string
122 "ogin:". If it fails to receive a login prompt within the time interval
123 allotted, it is to send a break sequence to the remote and then expect the
124 string "ogin:". If the first "ogin:" is received then the break sequence is
127 Once it received the login prompt the \fIchat\fR program will send the
128 string ppp and then expect the prompt "ssword:". When it receives the
129 prompt for the password, it will send the password hello2u2.
131 A carriage return is normally sent following the reply string.
133 expected in the "expect" string unless it is specifically requested by using
134 the \\r character sequence.
136 The expect sequence should contain only what is needed to identify the
138 Since it is normally stored on a disk file, it should not contain
139 variable information.
140 It is generally not acceptable to look for time
141 strings, network identification strings, or other variable pieces of data as
144 To help correct for characters which may be corrupted during the initial
145 sequence, look for the string "ogin:" rather than "login:". It is possible
146 that the leading "l" character may be received in error and you may never
147 find the string even though it was sent by the system.
149 scripts look for "ogin:" rather than "login:" and "ssword:" rather than
152 A very simple script might look like this:
154 ogin: ppp ssword: hello2u2
156 In other words, expect ....ogin:, send ppp, expect ...ssword:, send hello2u2.
158 In actual practice, simple scripts are rare.
159 At the vary least, you
160 should include sub-expect sequences should the original string not be
162 For example, consider the following script:
164 ogin:--ogin: ppp ssword: hello2u2
166 This would be a better script than the simple one used earlier.
168 for the same login: prompt, however, if one was not received, a single
169 return sequence is sent and then it will look for login: again.
171 noise obscure the first login prompt then sending the empty line will
172 usually generate a login prompt again.
174 Comments can be embedded in the chat script.
175 A comment is a line which
176 starts with the \fB#\fR (hash) character in column 1. Such comment
177 lines are just ignored by the chat program.
178 If a '#' character is to
179 be expected as the first character of the expect sequence, you should
180 quote the expect string.
181 If you want to wait for a prompt that starts with a # (hash)
182 character, you would have to write something like this:
184 # Now wait for the prompt and send logout string
190 Many modems will report the status of the call as a string.
192 strings may be \fBCONNECTED\fR or \fBNO CARRIER\fR or \fBBUSY\fR.
194 is often desirable to terminate the script should the modem fail to
195 connect to the remote.
196 The difficulty is that a script would not know
197 exactly which modem string it may receive.
198 On one attempt, it may
199 receive \fBBUSY\fR while the next time it may receive \fBNO CARRIER\fR.
201 These "abort" strings may be specified in the script using the \fIABORT\fR
203 It is written in the script as in the following example:
205 ABORT BUSY ABORT 'NO CARRIER' '' ATZ OK ATDT5551212 CONNECT
207 This sequence will expect nothing; and then send the string ATZ.
209 expected response to this is the string \fIOK\fR.
210 When it receives \fIOK\fR,
211 the string ATDT5551212 to dial the telephone.
212 The expected string is
214 If the string \fICONNECT\fR is received the remainder of the
216 However, should the modem find a busy telephone, it will
217 send the string \fIBUSY\fR.
218 This will cause the string to match the abort
220 The script will then fail because it found a match to
222 If it received the string \fINO CARRIER\fR, it will abort
223 for the same reason. Either string may be received.
225 terminate the \fIchat\fR script.
226 .SH CLR_ABORT STRINGS
227 This sequence allows for clearing previously set \fBABORT\fR strings.
228 \fBABORT\fR strings are kept in an array of a pre-determined size (at
229 compilation time); \fBCLR_ABORT\fR will reclaim the space for cleared
230 entries so that new strings can use that space.
232 The \fBSAY\fR directive allows the script to send strings to the user
233 at the terminal via standard error. If \fBchat\fR is being run by
234 pppd, and pppd is running as a daemon (detached from its controlling
235 terminal), standard error will normally be redirected to the file
236 /etc/ppp/connect-errors.
238 \fBSAY\fR strings must be enclosed in single or double quotes.
240 carriage return and line feed are needed in the string to be output,
241 you must explicitly add them to your string.
243 The SAY strings could be used to give progress messages in sections of
244 the script where you want to have 'ECHO OFF' but still let the user
245 know what is happening. An example is:
251 SAY "Dialling your ISP...\\n"
257 SAY "Waiting up to 2 minutes for connection ... "
261 SAY "Connected, now logging in ...\n"
268 SAY "Logged in OK ...\n"
271 This sequence will only present the SAY strings to the user and all
272 the details of the script will remain hidden.
274 above script works, the user will see:
278 Waiting up to 2 minutes for connection ... Connected, now logging in ...
284 A \fBreport\fR string is similar to the ABORT string.
286 is that the strings, and all characters to the next control character
287 such as a carriage return, are written to the report file.
289 The report strings may be used to isolate the transmission rate of the
290 modem's connect string and return the value to the chat user.
292 analysis of the report string logic occurs in conjunction with the
293 other string processing such as looking for the expect string.
295 of the same string for a report and abort sequence is probably not
296 very useful, however, it is possible.
298 The report strings to no change the completion code of the program.
300 These "report" strings may be specified in the script using the \fIREPORT\fR
302 It is written in the script as in the following example:
304 REPORT CONNECT ABORT BUSY '' ATDT5551212 CONNECT '' ogin: account
306 This sequence will expect nothing; and then send the string
307 ATDT5551212 to dial the telephone.
308 The expected string is
310 If the string \fICONNECT\fR is received the remainder
311 of the script is executed.
312 In addition the program will write to the
313 expect-file the string "CONNECT" plus any characters which follow it
314 such as the connection rate.
315 .SH CLR_REPORT STRINGS
316 This sequence allows for clearing previously set \fBREPORT\fR strings.
317 \fBREPORT\fR strings are kept in an array of a pre-determined size (at
318 compilation time); \fBCLR_REPORT\fR will reclaim the space for cleared
319 entries so that new strings can use that space.
321 The echo options controls whether the output from the modem is echoed
323 This option may be set with the \fI-e\fR option, but
324 it can also be controlled by the \fIECHO\fR keyword.
326 pair \fIECHO\fR \fION\fR enables echoing, and \fIECHO\fR \fIOFF\fR
328 With this keyword you can select which parts of the
329 conversation should be visible.
330 For instance, with the following
349 all output resulting from modem configuration and dialing is not visible,
350 but starting with the \fICONNECT\fR (or \fIBUSY\fR) message, everything
353 The HANGUP options control whether a modem hangup should be considered
354 as an error or not. This option is useful in scripts for dialling
355 systems which will hang up and call your system back. The HANGUP
356 options can be \fBON\fR or \fBOFF\fR.
358 When HANGUP is set OFF and the modem hangs up (e.g., after the first
359 stage of logging in to a callback system), \fBchat\fR will continue
360 running the script (e.g., waiting for the incoming call and second
361 stage login prompt). As soon as the incoming call is connected, you
362 should use the \fBHANGUP ON\fR directive to reinstall normal hang up
363 signal behavior. Here is an (simple) example script:
375 \'Callback login:' call_back_ID
381 \'Callback Password:' Call_back_password
391 ogin:--BREAK--ogin: real_account
396 The initial timeout value is 45 seconds.
397 This may be changed using the \fB-t\fR
400 To change the timeout value for the next expect string, the following
403 ATZ OK ATDT5551212 CONNECT TIMEOUT 10 ogin:--ogin: TIMEOUT 5 assword: hello2u2
405 This will change the timeout to 10 seconds when it expects the login:
407 The timeout is then changed to 5 seconds when it looks for the
410 The timeout, once changed, remains in effect until it is changed again.
412 The special reply string of \fIEOT\fR indicates that the chat program
413 should send an EOT character to the remote.
415 End-of-file character sequence.
416 A return character is not sent
419 The EOT sequence may be embedded into the send string using the
422 The special reply string of \fIBREAK\fR will cause a break condition
423 to be sent. The break is a special signal on the transmitter.
425 normal processing on the receiver is to change the transmission rate.
426 It may be used to cycle through the available transmission rates on
427 the remote until you are able to receive a valid login prompt.
429 The break sequence may be embedded into the send string using the
432 The expect and reply strings may contain escape sequences.
434 sequences are legal in the reply string.
435 Many are legal in the expect.
436 Those which are not valid in the expect sequence are so indicated.
439 Expects or sends a null string.
440 If you send a null string then it will still
441 send the return character.
442 This sequence may either be a pair of apostrophe
446 represents a backspace character.
449 Suppresses the newline at the end of the reply string.
451 method to send a string without a trailing return character.
453 be at the end of the send string.
455 the sequence hello\\c will simply send the characters h, e, l, l, o.
456 .I (not valid in expect.)
459 Delay for one second.
460 The program uses sleep(1) which will delay to a
461 maximum of one second.
462 .I (not valid in expect.)
466 .I (not valid in expect.)
469 Send a newline or linefeed character.
472 Send a null character.
473 The same sequence may be represented by \\0.
474 .I (not valid in expect.)
477 Pause for a fraction of a second.
478 The delay is 1/10th of a second.
479 .I (not valid in expect.)
482 Suppress writing the string to
485 written to the log in its place.
486 .I (not valid in expect.)
489 Send or expect a carriage return.
492 Represents a space character in the string.
493 This may be used when it
494 is not desirable to quote the strings which contains spaces.
496 sequence 'HI TIM' and HI\\sTIM are the same.
499 Send or expect a tab character.
502 Send or expect a backslash character.
505 Collapse the octal digits (ddd) into a single ASCII character and send that
507 .I (some characters are not valid in expect.)
510 Substitute the sequence with the control character represented by C.
511 For example, the character DC1 (17) is shown as \^^Q.
512 .I (some characters are not valid in expect.)
513 .SH TERMINATION CODES
514 The \fIchat\fR program will terminate with the following completion
518 The normal termination of the program.
519 This indicates that the script
520 was executed without error to the normal conclusion.
523 One or more of the parameters are invalid or an expect string was too
524 large for the internal buffers.
525 This indicates that the program as not
529 An error occurred during the execution of the program.
531 to a read or write operation failing for some reason or chat receiving
532 a signal such as SIGINT.
535 A timeout event occurred when there was an \fIexpect\fR string without
536 having a "-subsend" string.
537 This may mean that you did not program the
538 script correctly for the condition or that some unexpected event has
539 occurred and the expected string could not be found.
542 The first string marked as an \fIABORT\fR condition occurred.
545 The second string marked as an \fIABORT\fR condition occurred.
548 The third string marked as an \fIABORT\fR condition occurred.
551 The fourth string marked as an \fIABORT\fR condition occurred.
554 The other termination codes are also strings marked as an \fIABORT\fR
557 Using the termination code, it is possible to determine which event
558 terminated the script.
559 It is possible to decide if the string "BUSY"
560 was received from the modem as opposed to "NO DIAL TONE". While the
561 first event may be retried, the second will probably have little
562 chance of succeeding during a retry.
564 Additional information about \fIchat\fR scripts may be found with UUCP
566 The \fIchat\fR script was taken from the ideas proposed
567 by the scripts used by the \fIuucico\fR program.
569 uucico(1), uucp(1), syslog(3), syslogd(8).
571 The \fIchat\fR program is in public domain.
572 This is not the GNU public
574 If it breaks then you get to keep both pieces.
projects / FreeBSD / FreeBSD.git / blob