Provided by: manpages-zh_1.6.3.3-1_all bug

NAME

       chat - 與數據機自動溝通的指令稿

總覽 SYNOPSIS

       chat [ options ] script

描述 DESCRIPTION

       chat  程式在電腦與數據機之間定義溝通交換事宜。 它最主要的 目的是用來在點對點協定的隱形程式
       (pppd) 以及遠端的 pppd  程序 之間建立連線。

選項 OPTIONS

       -f <chat file>
              從  chat  檔案讀取  chat  指令稿。這個選項的使用與  chat  的  令稿參數互斥(mutually
              exclusive)。使用者必須具有存取該            檔案的讀取權。在檔案中允許多線(multiple
              lines)設定。應 該要以空白或是橫向定位(horizontal tab)字元來分隔字串。

       -t <timeout>
              對於所要接收的期待字串(expected                               string)設定逾時限制。
              如果在該時間限制內沒有接收到該字串的話那麼就不送出回覆      字串(reply    string)。
              可以送出一個變通(alternate)的回覆
              或者如果沒有變通的回覆字串則該指令稿將會失敗。一個失敗     的指令稿將會使得    chat
              程式以一個非零的錯誤碼結束。

       -r <report file>
              Set the file for output of the report strings. If you use the keyword  REPORT,  the
              resulting  strings  are  written  to  this file. If this option is not used and you
              still use REPORT keywords, the stderr file is used for the report strings.

       -e     Start with the echo option turned on. Echoing may also  be  turned  on  or  off  at
              specific  points  in  the  chat  script  by using the ECHO keyword. When echoing is
              enabled, all output from the modem is echoed to stderr.

       -E     Enables environment variable substituion within chat  scripts  using  the  standard
              $xxx syntax.

       -v     要求       chat       指令稿以冗長(verbose)模式執行。       這個       chat      程
              式接下來會將所有從數據機接收的文字以及輸出的字串記錄到  SYSLOG 去。The  default  is
              to  log  through  the  SYSLOG; the logging method may be altered with the -S and -s
              flags.

       -V     Request that the chat script be executed in a stderr verbose mode. The chat program
              will  then  log all text received from the modem and the output strings sent to the
              modem to the stderr device. This device is usually the local console at the station
              running the chat or pppd program.

       -s     Use  stderr.   All  log  messages  from '-v' and all error messages will be sent to
              stderr.

       -S     Do not use the SYSLOG.  By default, error messages are sent to the SYSLOG.  The use
              of  -S  will prevent both log messages from '-v' and error messages from being sent
              to the SYSLOG.

       -T <phone number>
              Pass in an arbitary string, usually a phone number, that will  be  substituted  for
              the \T substitution metacharacter in a send string.

       -U <phone number 2>
              Pass  in  a second string, usually a phone number, that will be substituted for the
              \U substitution metacharacter in a send string.  This is  useful  when  dialing  an
              ISDN terminal adapter that requires two numbers.

       script script  如果指令稿沒有以 -f 選項指定在檔案裡那麼該指令稿會如同  參數般被包含在 chat
              程式裡。

CHAT 腳本 SCRIPT

       chat 腳本定義通訊過程

       一個指令稿裡包含一個或多個〞期待對方送出(expect-send)〞的配對        字串(pairs         of
       string),以空白隔開,還有一個選擇性的〞期待對方                      送出之候補(subexpect-
       subsend)〞配對字串,以短線(dash)隔開。像 下面這個例子:

              ogin:-BREAK-ogin: ppp ssword: hello2u2

       這一行指示        chat        程式應該期待        "ogin:"         這個字串。如果在所分配的
       時間區間內接收簽入提示失敗的話,    那它就送出一個中斷程序(break   sequence)給遠端然後期待
       "ogin:" 這個字串。 如果第一個 "ogin:" 被接收到那麼中斷程序就不會產生。

       一旦它接收到該簽入提示則   chat   程式將會送出    ppp    這個字串然後期    待    "ssword:"
       這個提示。當它接收到密碼提示以後,它將會送出密碼 hello2u2 。

       一般在回覆字串後面會跟著送出一個機架返回(carriage    return)。在   〞期待〞字串裡除非以
       字元程序(character sequence)指定為必 須否則不會期待它的出現。

       期待程序(expect                              sequence)應該只包含辨認字串所需要的資料。因為
       它一般是儲放在磁碟檔案裡,它不應該包含變動的資訊。    通常以期待   字串來尋找時間字串(time
       strings),               網路辨識字串(network               iden-               tification
       strings),或是其它變動的資料是不被接受的。

       為求協助修正在初始化程序中(initial   sequence)   可能會傳送錯誤的  字元,所以尋找  "ogin:"
       這個字串而不是   "login:"   。    開頭的     "l"    字元可能接收錯誤而你永遠找不到該字串,
       即使它已經被系統送出。  因此緣故,指令稿尋找 "ogin:" 而不是 "login:" 以及 "ssword" 而 不是
       "password:" 。

       一個非常簡單的指令稿看起來可能像這樣:

              ogin: ppp ssword: hello2u2

       換句話說, 期待 ...ogin:,  送出 ppp,  期待 ...ssword:, 再送出 hello2u2 。

       在實際使用上,簡單的指令稿是罕見的。最少最少,                              原先的字串沒有
       被接收時你應該要把候補期待(sub-sequences)包括進來。例如,考慮 下面這個例子:

              ogin:--ogin: ppp ssword: hello2u2

       這會是一個比前面所用的簡單指令稿更好的指令稿。   這個會尋找相同  同的  login:  提示,然而,
       如果沒有接收到的話, 會送出一個單獨的 返回程序(return sequence)並且它會接著再次尋找 login:
       。要是雜      雜訊掩蓋掉第一個      login      提示那麼接著送出空線路(empty      line)經常
       將會再次產生簽入提示。

COMMENTS

       Comments can be embedded in the chat script. A comment is a line which starts with  the  #
       (hash)  character in column 1. Such comment lines are just ignored by the chat program. If
       a '#' character is to be expected as the first  character  of  the  expect  sequence,  you
       should  quote  the  expect  string.  If you want to wait for a prompt that starts with a #
       (hash) character, you would have to write something like this:

              # Now wait for the prompt and send logout string
              ´# ' logout

SENDING DATA FROM A FILE

       If the string to send starts with an at sign (@), the rest of the string is  taken  to  be
       the  name  of a file to read to get the string to send.  If the last character of the data
       read is a newline, it is removed.  The file can be a named pipe (or  fifo)  instead  of  a
       regular  file.   This  provides  a  way  for chat to communicate with another program, for
       example, a program to prompt the user and receive a password typed in.

放棄字符串 ABORT STRINGS

       許多數據機會以字串來回報呼叫的狀況。 這些字串可能是 CONNECTED 或是 NO CARRIER 或是 BUSY 。
       通常要是數據機連線到遠端失敗的話                                    應該會希望結束指令稿。
       困難是指令稿不會確實地知道它可能接收到  哪個數據機字串。在某次嘗試時,  他可能接收到  BUSY
       然而下次它可 能接收到 NO CARRIER 。

       這些〞失敗〞字串可以用 ABORT 程序指定到指令稿中。像是下面這個 例子般地寫到指令稿裡:

              ABORT BUSY ABORT 'NO CARRIER' '' ATZ OK ATDT5551212 CONNECT

       這個程序將不會期待什麼;而且接著送出      ATZ      這個字串。對此期待的      回應是     OK
       這個字串。當它接收到 OK 時,字串 ADTD5551212 就進行 撥號。期待字串是 CONNECT  。  如果字串
       CONNECT  被接收到那麼就會 執行指令稿其餘的部份。然而,要是數據機發現電話忙線, 他將會送 出
       BUSY      這個字串。       這會使得該字串符合失敗字元程序(abort       char-       acter)。
       這個指令稿將會因為它發現一個失敗字串(abort   string)而   失敗(fail)。如果他接收到的是   NO
       CARRIER 字串, 它也會因為同樣 的原因而失敗。不是可以接收到字串就是字串將終結 chat 指令稿。

CLR_ABORT STRINGS

       This sequence allows for clearing previously set ABORT strings.  ABORT strings are kept in
       an  array of a pre-determined size (at compilation time); CLR_ABORT will reclaim the space
       for cleared entries so that new strings can use that space.

SAY STRINGS

       The SAY directive allows the script to send strings  to  the  user  at  the  terminal  via
       standard  error.   If chat is being run by pppd, and pppd is running as a daemon (detached
       from its controlling terminal), standard error will normally be  redirected  to  the  file
       /etc/ppp/connect-errors.

       SAY  strings must be enclosed in single or double quotes. If carriage return and line feed
       are needed in the string to be output, you must explicitely add them to your string.

       The SAY strings could be used to give progress messages in sections of  the  script  where
       you want to have 'ECHO OFF' but still let the user know what is happening.  An example is:

              ABORT BUSY
              ECHO OFF
              SAY "Dialling your ISP...\n"
              ´' ATDT5551212
              TIMEOUT 120
              SAY "Waiting up to 2 minutes for connection ... "
              CONNECT ''
              SAY "Connected, now logging in ...0
              ogin: account
              ssword: pass
              $ SAY "Logged in OK ...0 etc ...

       This  sequence  will  only  present the SAY strings to the user and all the details of the
       script will remain hidden. For example, if the above script works, the user will see:

              Dialling your ISP...
              Waiting up to 2 minutes for connection ... Connected, now logging in ...
              Logged in OK ...

REPORT STRINGS

       A report string is similar to the ABORT string. The difference is that  the  strings,  and
       all characters to the next control character such as a carriage return, are written to the
       report file.

       The report strings may be used to isolate the transmission rate  of  the  modem's  connect
       string  and  return  the  value  to the chat user. The analysis of the report string logic
       occurs in conjunction with the other string processing such  as  looking  for  the  expect
       string.  The  use  of the same string for a report and abort sequence is probably not very
       useful, however, it is possible.

       The report strings to no change the completion code of the program.

       These "report" strings may be specified in the script using the  REPORT  sequence.  It  is
       written in the script as in the following example:

              REPORT CONNECT ABORT BUSY '' ATDT5551212 CONNECT '' ogin: account

       This  sequence  will  expect  nothing;  and  then  send the string ATDT5551212 to dial the
       telephone. The expected string is CONNECT. If the string CONNECT is received the remainder
       of  the  script  is  executed.  In  addition the program will write to the expect-file the
       string "CONNECT" plus any characters which follow it such as the connection rate.

CLR_REPORT STRINGS

       This sequence allows for clearing previously set REPORT strings.  REPORT strings are  kept
       in  an  array  of a pre-determined size (at compilation time); CLR_REPORT will reclaim the
       space for cleared entries so that new strings can use that space.

ECHO

       The echo options controls whether the output from the modem  is  echoed  to  stderr.  This
       option  may  be set with the -e option, but it can also be controlled by the ECHO keyword.
       The "expect-send" pair ECHO ON enables echoing,  and  ECHO  OFF  disables  it.  With  this
       keyword  you  can  select which parts of the conversation should be visible. For instance,
       with the following script:

              ABORT   'BUSY'
              ABORT   'NO CARRIER'
               ''
              ATZ
              OK\r\n  ATD1234567
              \r\n    \c
              ECHO    ON
              CONNECT \c
              ogin:   account

       all output resulting from modem configuration and dialing is  not  visible,  but  starting
       with the CONNECT (or BUSY) message, everything will be echoed.

HANGUP

       The HANGUP options control whether a modem hangup should be considered as an error or not.
       This option is useful in scripts for dialling systems which will hang  up  and  call  your
       system back.  The HANGUP options can be ON or OFF.
       When  HANGUP  is set OFF and the modem hangs up (e.g., after the first stage of logging in
       to a callback system), chat will continue  running  the  script  (e.g.,  waiting  for  the
       incoming  call  and second stage login prompt). As soon as the incoming call is connected,
       you should use the HANGUP ON directive to reinstall normal hang up signal behavior.   Here
       is an (simple) example script:

              ABORT   'BUSY'
              ´´      ATZ
              OK\r\n  ATD1234567
              \r\n    \c
              CONNECT \c
              ´Callback login:' call_back_ID
              HANGUP OFF
              ABORT "Bad Login"
              ´Callback Password:' Call_back_password
              TIMEOUT 120
              CONNECT \c
              HANGUP ON
              ABORT "NO CARRIER"
              ogin:--BREAK--ogin: real_account
              etc ...

超時 TIMEOUT

       初始的逾時值是 45 秒。這可以用 -t 參數來加以改變。

       要對下一個期待字串改變逾時值的話,可以使用下面這個例子:

              ATZ OK ATDT5551212 CONNECT TIMEOUT 10 ogin:--ogin: TIMEOUT 5 assword: hello2u2

       這將會在期待       "login:"       提示的時候把逾時限制改成       10       秒。      逾時限
       制接著在它尋找密碼提示時被改成 5 秒。

       逾時限制一旦改變就會持續作用直到它再度被改變。

SENDING 發送 EOT

       EOT      這個特別的回覆字串指示       chat       程式應該送出一個       EOT       字元到遠
       端去。這是一般的檔案結束(End-of-file)字元程序。           在           EOT          後面並
       不會跟著送出一個返回字元(return)。

       這個 EOT 程序可以用 ^D 序列嵌入到送出的字串裡。

產生中斷 GENERATING BREAK

       BREAK               這個特別的回覆字串將會使得一個中斷情況被送出。                這個中斷
       是傳送端的一個特殊。接收端一般對此的處理是改變傳輸率。                              它可以
       用來循環測試遠端可能的傳輸率直到你能夠接到有效的簽入提示。

       這個中斷程序可以用 \K  序列嵌入到送出的字串裡。

轉義序列 ESCAPE SEQUENCES

       期待以及回覆字串可以包含轉義序列。                              所有這種程序在回覆字串中都
       是合法的。有許多在期待字串中是合法的。 那些在期待程序中無效的 會被指出。

       ''     期待或送出一個空字串(null                string)               。如果你送出一個空字
              串那麼它還會送出一個返回字元。這個程序可以是一對省略符
              號(apostrophe)或者也可以是引用字元。

       \b     代表一個退位(backspace)字元。

       \c     抑制在回覆字串結尾的新列(newline)字元。                              這是送出沒有返
              回字元尾隨的字串的唯一方法。它必須在送出字串的結尾。例  如,這個程序 hello

       \d     延遲一秒鐘。該程式使用最長延遲為一秒的 sleep(1) 。(在  期待字串中無效。)

       \K     插入一個中斷(在期待字串中無效。)

       \n     送出一個新列(newline)或換行(linefeed)字元。

       \N     送出一個空字元(null character)。同樣的程序可以用   代  替。(在期待字串中無效。)

       \p     暫停一小段時間。延遲 1/10 秒。(在期待字串中無效。)

       \q     抑制字串寫往        SYSLOG        檔案。該        ??????         字串被記錄到自己的
              空間。(在期待字串中無效。)

       \r     傳送或期待一個機架返回(字元)

       \s     代替字串中的空白。這個可以用在不願引用包含空白的字串之時。'HI   TIM'  以及  HI\sTIM
              是相同的。

       \t     傳送或期待一個定位(tab)字元。

       \T     Send the phone number string as specified with the -T option (not valid in expect.)

       \U     Send the phone number 2 string as specified  with  the  -U  option  (not  valid  in
              expect.)

       \\     傳送或期待一個倒斜線(backslash)字元。

       \ddd   將八進位數字         (ddd)        折疊(collapse)成單一的        ASCII        字元並
              將其送出。(某些字元在期待字串中無效。)

       ^C     替換含有以     C     代表之控制字元的程序。例如,字元     DC1(17)      是以      ^Q
              表示。(某些字元在期待字串中無效。)

ENVIRONMENT VARIABLES

       Environment  variables  are available within chat scripts, if  the -E option was specified
       in the command line. The metacharacter $ is used to introduce the name of the  environment
       variable  to  substitute.  If  the  substition  fails,  because  the requested environment
       variable is not set, nothing is replaced for the variable.

TERMINATION CODES

       The chat program will terminate with the following completion codes.

       0      The normal termination of the program. This indicates that the script was  executed
              without error to the normal conclusion.

       1      One or more of the parameters are invalid or an expect string was too large for the
              internal buffers. This indicates that the program as not properly executed.

       2      An error occurred during the execution of the program. This may be due to a read or
              write operation failing for some reason or chat receiving a signal such as SIGINT.

       3      A  timeout  event  occurred  when  there  was  an  expect  string  without having a
              "-subsend" string. This may mean that you did not program the script correctly  for
              the  condition  or  that some unexpected event has occurred and the expected string
              could not be found.

       4      The first string marked as an ABORT condition occurred.

       5      The second string marked as an ABORT condition occurred.

       6      The third string marked as an ABORT condition occurred.

       7      The fourth string marked as an ABORT condition occurred.

       ...    The other termination codes are also strings marked as an ABORT condition.

       Using the termination code, it is possible to determine which event terminated the script.
       It  is  possible  to decide if the string "BUSY" was received from the modem as opposed to
       "NO DIAL TONE". While the first event may be retried, the second will probably have little
       chance of succeeding during a retry.

參見 SEE ALSO

       關於   chat   指令稿的其它資訊可以在   UUCP   文件裡找到。chat   指令稿   的概念由  uucico
       程式所使用的指令稿來的。

       uucico(1), uucp(1)

COPYRIGHT

       The chat program is in public domain. This is not the GNU public  license.  If  it  breaks
       then you get to keep both pieces.

[中文版維護人]

       asdchen <asdchen@pc2.hinet.net>

[中文版最新更新]

       1995/09/30

《中國linux論壇man手冊翻譯計劃》:

       http://cmpp.linuxforum.net

       本頁面中文版由中文 man 手冊頁計劃提供。
       中文 man 手冊頁計劃:https://github.com/man-pages-zh/manpages-zh