_p_cmd.txt

一个通讯程序源码

displayed.

The majority of procedure tracing features use the current trace
state (from the
.B ptrace
command setting) as a binary condition.  That is, either tracing is done
or not.  However,
.B expresp
adds the tracing level to the number of -v switches to determine its
verbosity level.

Escape sequences allow you to insert special or variable
information in your expect and respond strings.  Escape sequences
begin with either the backslash or the tilde.  NOTE: remember to
use two backslashes inside a literal string constant to get one
backslash in the resulting string.  The procedure language's
string parser has it's own use for a single backslash followed by
another character.  For instance:

.DS L
    set $s0='\e\eM' sets $s00 to '\eM'
.DE

Some of the escape sequnces have meaning in both expect and respond
tokens while others have a use in only of of the two types.

.DS L
   Meaning of the escape sequences:
   \eD - current phone number
   \eE - turn on echo checking when sending (for slow devices)
   \eK - send a BREAK
   \eM - turn on line CLOCAL 
   \eN - null byte (same as \e000)
   \eT - current phone number with Dialcodes and
         character translation
   \ec - append no new-line to send string (must be last
            "character" in a send string)
   \ed - delay (2 seconds) 
   \ee - turn off echo checking when sending
   \em - turn off line CLOCAL 
   \en - send or expect new-line
   \ep - pause (approximately 1/4-1/2 second delay)
   \er - send or expect carriage return
   \e\e - send or expect backslash (same as \e134)
   \e~ - send or expect tilde (same as \e176)
   \e### - send or expect character respresenting three
           character octal value ### (*MUST* be three digits
           with leading zeroes as necessary)
   ~m[##] - set expect timeout to ## milliseconds (NOT
            SUPPORTED BY DIALERS; SEE BELOW)
   ~n[##] - nap ## milliseconds (NOT SUPPORTED BY DIALERS;
           SEE BELOW)
   ~t[##] - set expect timeout to ## seconds (NOT SUPPORTED
            BY DIALERS; SEE BELOW)
   Speed - Hayes-style CONNECT handler (as sole contents of
           an expect string, equivalent to using CONNECT)
.DE

<timeout_msecs> specifies an optional timeout in milliseconds
for waiting on expect strings;  it defaults to 10,000 milliseconds
(10 seconds).
The resolution for timeouts is limited to the basic tick time of
your system (HZ, 10 msec for UNIX/386 3.2.0,
16 (1000/60) msec for 3.2.1 (ODT 1.0) and 3.2v2 (ODT 1.1),
back to 10 msec for 3.2v4 (ODT 2.0) and
20 msec for XENIX/386 and XENIX/286). Whew!
The timeout for 'Speed' expects is fixed at 90 seconds.

~t[##] and ~m[##] may appear at the beginning of an expect portion
of a script.  They set the expect timeout delay in seconds and
milliseconds, respectively.  The ## is a decimal number; if it is
specified <= 0, there will be no delay.  The initial timeout set
for each execution of the expresp command is 10 seconds.  The
timeout period remains as you set it for the remainder of the
script unless you change it again.

.DS L
Examples:

    ~t[20]gin:      look for "gin:" for 20 seconds
    ~m[500]\001     look for STX for 500 milliseconds
    "" ~t[3]gin:--gin: uname ~t[10]word: secret
.DE

~n[##] may appear anywhere in a respond portion of a script.  
It causes ECU to nap the number of milliseconds specified
by the decimal ## argument.  This function was served by \em prior
to ECU 3.20.  Addition of SVR4 \eM and \em necessitated
the change.

.DS L
Example:

    a~n[20]b~n[20]c   send "abc" with 20 msec between each
                      character
.DE


Integer variable $i0 is set to one if the expect-respond script 
fails, else it is set to 0.

.*s 2 "fchmod"

usage: fchmod <mode> <filenum>

This command sets the mode of <filenum> to <mode>.
The <mode> argument takes one of two forms, a nine-character
mode string (e.g., 'rwxr-xr-x') or an integer value (0755).
The <filenum> argument is either a string value forming a
filename or an integer file number representing a file opened with the
.B fopen
command.

The command sets $i0 = 0 if successful, else to the
.B errno
from the associated system call (refer to the 
.B %errstr
string function and/or /usr/include/sys/errno.h).

.DS L
Example:

    fopen 1 '/tmp/123'; fchmod 'rwxrwxrwx' 1
    fchmod 'rwxrwxrwx' '/tmp/123'
    fopen 1 '/tmp/123'; fchmod 0777 1
    $i0 = 0777; fchmod $i0 '/tmp/123'

All of the above example result in the same result.
.DE

.*s 2 "fclose"

usage: fclose <filenum>

This command closes <filenum>.
The <filenum> argument is an
integer file number representing a file opened with the
.B fopen
command.

The command is ignored if <filenum> is not open.
No integer variable is modified by
.I fclose .

.DS L
Example:

    fclose 1
.DE

.*s 2 "fdel"

usage: fdel <filenum>

This command removes a file.

The command sets $i0 = 0 if successful, else to the
.B errno
from the associated system call (refer to the 
.B %errstr
string function and/or /usr/include/sys/errno.h).

.DS L
Example:

    fdel '/tmp/123'
.DE

.*s 2 "fgetc"

usage: fgetc <filenum> <destination>

This command reads a character from <filenum>.
The <filenum> argument is an
integer file number representing a file opened with the
.B fopen
command.

The argument <destination> is either a string variable
or an integer variable.
If the file has reached end of file: an integer variable
receives -1; a string variable is returned null.
Otherwise, the character's numeric value (0-255) is placed
in an integer variable or a string variable is returned with a
length of one with the file character as its only character.

.DS L
Example:

    fgetc 1 $s0
    fgetc 1 $i_input
.DE

.*s 2 "fgets"

usage: fgets <filenum> <strvar>

This command reads a character from <filenum>.
The <filenum> argument is an
integer file number representing a file opened with the
.B fopen
command.

The argument <strvar> is a string variable.
If the file has reached end of file, <strvar> is returned null and
integer variable $i0 is set to 1.
Otherwise, the <strvar> receives input from the file minus
the trailing newline and $i0 is returned zero.

.DS L
Example:

    fgets 1 $s0
.DE

.*s 2 "fkey"

.DS L
usage: fkey <str>
       fkey -r
.DE

This command selects a function key definition from the ~/.ecu/keys
file.  The -r version resets to the original defaults, plust
loads any entry in keys named "default".

.*s 2 "fkmap"
.DS L
usage: fkmap 
       fkmap <keyname>
       fkmap <keyname> <keylist>
       fkmap -l <name>
       fkmap -r
       fkmap -s <file>
.DE

This command manages the mechanism ECU uses to recognize function
keys when they are entered at the console.  Entering the command
with no arguments displays the current mapping in funckeymap format.

If supplied, the first argument to the command must be the
recognized name of a function key from the list:
.DS L
 F1 F2 F3 F4 F5 F6 F7 F8 F9 F10 F11 F12
 Home End PgUp PgDn CUP CUL CU5 CUR CUD
.DE
The case of the entered argument is unimportant.

If only one argument is supplied, the mapping for the specified key
is displayed.  If more than one argument is supplied, the keyboard
mapping is changed.  Arguments 2-n are character code specifiers
in the format used to define a funckeymap entry.
.B WARNING :
If found to be syntactically correct, a mapping change
is installed immediately.  If incorrect mapping of the HOME
key is requested, you may lose control of ECU.

The -l form reads an entire funckeymap definition matching <name>
from ~/.ecu/funckeymap (if not found there, in a file by the same
name in the library directory).  This form behaves exactly
in the same manner as the command line switch -F.
Due to the drastic nature of this command, if it fails to
execute properly, ECU terminates itself.  Note that
improper use of this form of the command can still render
ECU an albatross (with Home unrecognizable).

The -r form rereads the original funckeymap definition (as
at program invocation), reseting the mapping.  The -s switch
saves the current mapping to <file>.

Note: the fkmap command line must contain literal text.
No variable or expression expansions are not done.
Switches may not be combined.  Only one switch may appear.

.DS L
Examples:

    fkmap f10       display F10 mapping
    fkmap Home ^Z   map Home to ^Z
                    after this command, type ^Z for Home
.DE

.*s 2 "flush"

usage: flush

This command causes any characters received by the system
from the line, but not yet read by the procedure to be "forgotten"
or flushed.

.*s 2 "fopen"

usage: fopen [-<mode>] <filenum> <filename>

This command opens a file named by the string argument <filename>
and associates it with the user-chosen file number <filenum> (which
must be an integer value between 0 and 4, inclusive).

The argument switches govern how a file is opened and must be chosen
from this list:
.VL 15 4
.LI -r
The file is opened read-only; if it does not
exist, an error occurs.
.LI -r+
The file is opened for reading and writing; if it does not
exist, an error occurs.
.LI -w
The file is opened for writing (any previous contents
of the file are lost); if it does not
exist, it is created.
.LI -w+
The file is opened for reading and writing (any previous contents
of the file are lost); if it does not
exist, it is created.
.LI -a
The file is opened for appending (writes to the file
are added to the previous file contents); if it does not
exist, it is created.
All writes are appended to the file (the
.B fseek
command has no effect).
.LE

The switches argument may be omitted; in such cases,
the file is opened as though '-r' had been supplied.  However,
if procedure tracing is enabled (see the description of the
interactive and procedure command
.B ptrace ),
a warning message will be issued.

The command sets $i0 = 0 if successful, else to the
.B errno
from the associated system call (refer to the 
.B %errstr
string function and/or /usr/include/sys/errno.h).
.DS L
Example:

    fopen 0 -r '/etc/passwd'
    fopen 1 -w+ '/tmp/123'
    fopen 2 -a 'tranact.log'
.DE

.*s 2 "fputc"

usage: fputc <filenum> <char>

This command writes character <char> into <filenum>.
The <filenum> argument is an
integer file number representing a file opened with the
.B fopen
command.
Argument <char> is a integer value of which the lower eight
bits are used or a string value of which the first character is used.

If a write error occurs, procedure execution is terminated.
.DS L
Example:

    $s0='abc'; fputc 1 $s0        writes 'a'
    $i0=0x30 ; fputc 1 $i0        writes '0'
.DE

.*s 2 "fputs"

usage: fputs [-n] <filenum> <str>

This command writes the string <str> into <filenum>.
The <filenum> argument is an
integer file number representing a file opened with the
.B fopen
command.

If the switch '-n' is omitted, a newline is appended after <str>
in the file; if present, no newline is written.

If a write error occurs, procedure execution is terminated.
.DS L
Example:

    $s0='abc'; fputc 1 $s0        writes 'a'
.DE

.*s 2 "fseek"

usage: fseek <filenum> <position>

This command sets the file position of <filenum> to <position>,
an integer value.
The corresponding integer function
.B %ftell
may be used to determine the current file position.

.B Note :
if <filenum> is open for append ('-a'), then the
.B fseek
command will have no effect.

.*s 2 "getf"

.DS L
usage: getf -x <int-var-spec> <offset>

where: -x ==
   -b byte
   -w word (little-endian)
   -W word (big-endian)
   -l 32-bits (little-endian)
   -L 32-bits (big-endian)
.DE

.*s 2 "gosub"

usage: gosub <label>

This command transfers control of procedure to a statement
other than the one immediately following.  The <label>
argument may be literal text or may be a string, allowing
a "computed gosub" feature.

When the next return statement is executed, control is
returned to the 
next statement after the gosub.

.DS L
Example:

    gosub GET_NEXT
    gosub 'GET_NEXT'
    gosub 'GET'+'_NEXT'
    $s0 = 'GET_NEXT'; gosub $s0
    $s0 = 'NEXT'; gosub 'GET_'+$s0

Note: all the above examples cause transfer to the label GET_NEXT.
.DE
.DS L
A switch or case function of sorts may be implemented by something like:

    #$i0 has been set to the "switch" value
    ifi $i0 < 0 || $i0 > 2  # avoid gosub label not found
    {
        echo 'bad my_case state value'+%itos($i0)
        DO SOMETHING LIKE DIE OR DUMP VARS AND DIE
    }
    $s0 = 'my_case_'+%itos($i0,03)
    gosub $s0

my_case_000
    echo 'handle case 0'
    return

my_case_001
    echo 'handle case 1'
    return

my_case_002
    ifi $i_already_did_002
    {
        echo 'whoops'
        return
    }
    echo 'handle case 2'
    $i_already_did_002 = 1
    return
.DE

.*s 2 "gosubb"

usage: gosubb <label>

This command serves the same function as the
.B gosub
command except the programmer is signifying that the label
is
.B b ehind
the current statement, resulting in slightly faster execution.
(The label is not REQUIRED to be at any specific location
in the procedure relative to the
.B gosubb
statement.)

.*s 2 "goto"

usage: goto <label>

This command transfers control of procedure to a statement
other than the one immediately following.  The <label>
argument may be literal text or may be a string, allowing
a "computed goto" feature.
.DS L
Example:

    goto GET_NEXT
    goto 'GET_NEXT'
    goto 'GET'+'_NEXT'
    $s0 = 'GET_NEXT'; goto $s0
    $s0 = 'NEXT'; goto 'GET_'+$s0
.DE
Note: all the above examples cause transfer to the label GET_NEXT.

.*s 2 "gotob"

usage: gotob <label>

This command serves the same function as the
.B goto
command except the programmer is signifying that the label
is
.B b ehind
the current statement, resulting in slightly faster execution.
(The label is not REQUIRED to be at any specific location
in the procedure relative to the
.B gotob
statement.)

.*s 2 "hangup"

usage: hangup

This command causes Data Terminal Ready (DTR)
to be dropped momentarily, causing (hopefully)
the termination of any current connection
to a remote system. 
This command is only effective if the attached Data Communications
Equipment is configured
to terminate its connection on loss of DTR.

If no line is attached, the command is ignored (a warning
is generated if procedure tracing is enabled).

.*s 2 "hexdump"

.DS L
usage: hexdump [-s] <str>
       hexdump -t[s] <str1> <str>

<str> buf to dump
<str1> title (if -t)
-s short (terse) dump
.DE

This command prints a hexadecimal dump of <str> on the screen
(and to the procedure log file, if logging enabled with the
.B ptrace
command).

The switch '-t' signifies that <str1> is a title to be printed
.DS L
Example:

    $s0='The quick brown fox jumped over the lazy dog\e's back'
    hexdump -t 'Example hex dump' $s0
---------------------------- Example hex dump ----------------------------
0000  54 68 65 20 71 75 69 63 6B 20 62 72 6F 77 6E 20 | The quick brown  |
0010  66 6F 78 20 6A 75 6D 70 65 64 20 6F 76 65 72 20 | fox jumped over  |
0020  74 68 65 20 6C 61 7A 79 20 64 6F 67 27 73 20 62 | the lazy dog's b |
0030  61 63 6B                                        | ack              |
.DE
.DS L
    hexdump %left($s0,9)
0000  54 68 65 20 71 75 69 63 6B                      | The quick        |