_features.txt

一个通讯程序源码

if using ECU from remote.

.*s 2 "Function Key Actions"

This section deals with how ECU behaves
once a function key has been recognized as having been entered
at the keyboard. 

.*s 3 "Standard Function Keys"

All function keys with the exception of the 
.B Home ,
.B BkTab
(shift TAB),
and keypad unshifted 5 key can be programmed to 
transmit preselected character sequences when the key is pressed.

The default values for these sequences is shown below.

.DS L
Identifier Description    Default Sequence
--------   ------------   ----------------
F1         F1                ESC [ M
F2         F2                ESC [ N
F3         F3                ESC [ O
F4         F4                ESC [ P
F5         F5                ESC [ Q
F6         F6                ESC [ R
F7         F7                ESC [ S
F8         F8                ESC [ T
F9         F9                ESC [ U
F10        F10               ESC [ V
F11        F11               ESC [ W
F12        F12               ESC [ X
Home       Home          <-- intercepted (not an input key)
End        End               ESC [ F
PgUp       Page up           ESC [ I
PgDn       Page down         ESC [ G
CUU        Up arrow          ESC [ A
CUD        Down arrow        ESC [ B
CUL        Left arrow        ESC [ D
CUR        Right arrow       ESC [ C
CU5        "Cursor 5"    <-- intercepted (not an input key)
Ins        Insert            ESC [ L
.DE
 
This results in the following interactive "fkey" command display:
.DS L
 F1   SCO F1    F2   SCO F2    Home  ecu cmd       PgUp  SCO PgUp
 F3   SCO F3    F4   SCO F4    End   SCO End       PgDn  SCO PgDn
 F5   SCO F5    F6   SCO F6    Ins   local shell   CUR5  screen dump
 F7   SCO F7    F8   SCO F8    BkTab redisplay  
 F9   SCO F9    F10  SCO F10   CUR^  SCO CUU       CUR>  SCO CUR
 F11  SCO F11   F12  SCO F12   CUR<  SCO CUL       CURv  SCO CUD
.DE

You may override the default setting by using the interactive or
procedure command "fkey" to specify a new keyset definition
from ~/.ecu/keys.

Function keyset definitions are appended one after another
to ~/.ecu/keys.  The keyset name appears on a line by itself
and the choices making up a set appear on subsequent lines
of a special format.  

A keyset is loaded explicitly using "fkey" and implicitly when
connecting to a remote system and a keyset name matches
the dialing directory entry name.

Consider the example:

.DS L
stratus
    F1:F1:esc O q
    F2:F2:esc O r
    F3:F3:esc O s
    F4:F4:esc O t
    F5:F5:esc O u
    F6:F6:esc O v
    F7:F7:esc O w
    F8:status:dc4
    F9:no status:nl
    F10:redisp:esc O y
    F11:redisp:syn
    PGDN:cancel:esc O Q
    END:enter:esc O M
    PGUP:dispform:esc O R
    CUU:^:dle
    CUD:v:so
    CUL:<:stx
    CUR:>:ack
.DE

The key definition lines are made up of three fields.  In addition,
there must be a blank or a space in the first column of the line.
The first field is the ECU key identifier from the table above.
The second field is a 12-character max string to display when
the display option of the fkey command is used.
The last field is a character sequence to be transmitted when
the key is pressed.

The resulting fkey display for the stratus example looks similar to:

.DS L
 F1  F1     F2  F2         Home ecu cmd     PgUp  dispform
 F3  F3     F4  F4         End  enter       PgDn  cancel
 F5  F5     F6  F6         Ins  local shell CUR5  Screen dump
 F7  status F8  no status  BkTab restore receiver display
 F9         F10 redisp     CUR^ ^           CUR>  >
 F11        F12            CUR< <           CURv  v
.DE

Pressing F1, causes the three characters ESC, 'O' and 'q' to be
transmitted.

.*s 3 "SCO ALT-[a-z] Function Keys"

If you are on an SCO machine and you have installed the custom ECU mapkey file
(as described in the release directory
in mapkeys/README), then ALT-a through ALT-z causes the "silent"
execution of procedures 'alt_a.ep' for ALT-a, 'alt_b.ep' for ALT-b, etc.
The models subdirectory contains an example alt_h.ep which will home
the cursor when ALT-h is pressed.  This facility allows the execution
of 26 procedures without ECU itself changing the video display at all.
Any changes to the display (short of procedure errors) will result
solely from the action of the invoked procedure.
If the procedure matching the ALT-[a-z] key pressed cannot be found,
a short error message is printed and the terminal bell is rung.
(Using back tab may be used to refresh the display in this event.)

NOTE: ECU 3.10 CHANGES TO THE SINGLE KEY PROCEDURE FUNCTIONALITY
MAKE IT NECESSARY FOR YOU TO REVIEW mapkeys/README IF YOU HAVE USED
THIS FEATURE IN PREVIOUS REVISIONS.

The strings used to represent "non-printable" characters are identical
to the formal ASCII names given them (without regard to case), viz:
.DS I
      NUL may not appear in a function key definition

0x00 nul    0x10 dle 
0x01 soh    0x11 dc1 
0x02 stx    0x12 dc2 
0x03 etx    0x13 dc3 
0x04 eot    0x14 dc4 
0x05 enq    0x15 nak 
0x06 ack    0x16 syn 
0x07 bel    0x17 etb 
0x08 bs     0x18 can 
0x09 ht     0x19 em  
0x0A nl     0x1A sub 
0x0B vt     0x1B esc 
0x0C np     0x1C fs  
0x0D cr     0x1D gs  
0x0E so     0x1E rs  
0x0F si     0x1F us  
            0x20 sp  
            0x7F del 
.DE

.*s 2 "Line Editing"

When you are entering a line of text for an ecu command or in
a field on a screen, you may edit it in a number of ways at any
time prior to pressing Enter.  Cursor Left moves the cursor left
by one character position, nondestructively.  Cursor Right moves
to the right.  Insert toggles insert mode.  Backspace (your
erase key as specified to stty in commands, the actual backspace key
in screens) deletes the character to the left of the cursor.
Your line kill key (as specified to stty) in command mode or
the ^U character in screen mode erases the entire line.  Esc
in command mode cancels the command.  Esc in screen mode usually
cancels the screen or subfunction in a screen.  ^L or ^R in
interactive command mode shows the current state of Insert mode and
redisplays the edited string.

.*s 2 "Screen Dump"
When the "cursor 5" key is pressed, the screen contents are
dumped to a file.  By default, this file is named '~/.ecu/screen.dump'.
The
.B sdname
interactive command either displays or changes the current screen
dump file name, depending upon whether or not an argument
is supplied.
The
.B scrdump
procedure command can initiate a dump.

Note that from an SCO multiscreen, screen dump produces a dump of the
actual screen contents (it is obtained from
the video driver), including ecu-generated output.  When
using a non-multiscreen terminal, screen dump dumps only the
shared memory virtual screen as received from the host.

If, at a multiscreen, you wish a screen dump free of ecu output
"pollution," use Shift-Tab (BkTab) to redraw the screen, then
perform the screen dump.  If you are not on a multiscreen, then the
screen dump comes from the (sometimes inexact) screen memory
representation and this step is not necessary.

.*s 3 "Multiscreen and Non-Multiscreen"
Note that from multiscreens, screen dump produces a dump of the
actual screen contents, including ECU-generated output.  When
using a non-multiscreen terminal, screen dump dumps only the 
shared memory virtual screen as received from the host.
If standard input is not a serial line (xterm or /dev/null),
screen dumps will be of the non-multiscreen type.

If, at a multiscreen, you wish a screen dump free of ECU output
"pollution," use Shift-Tab (BkTab) to redraw the screen, then
perform the screen dump.

.*s 3 "Multiscreen Bug"
There has been a bug in the multiscreen driver for some time
wherein a MEDIA COPY (screen dump) sequence ("ESC [ 2 i") leaves
the "ESC [ 2" part "active".  When a screen dump (Cursor 5)
command is given, I do the screen dump, then send a "l" to the
screen to work around the bug ("ESC 2 [ l" unlocks the keyboard,
essentially a no-op).  If and when it gets fixed, you'll see an
"l" show up on your screen after a screen dump sequence.  To fix
this, comment out the
.DS I
#define MULTISCREEN_DUMP_BUG
.DE
at the top of ecuscrdump.c.

.*s 2 "Interactive Command History"

After pressing the Home key, pressing it again invokes the
interactive command history function.  After the second
Home key is pressed, the last interactive command is
redisplayed. Line editing may be performed on the command as described
in the previous section.

Additionally, using the Cursor Up key accesses less recent commands.
The Cursor Down key accesses more recent commands.  Pressing Enter causes
the command to be executed.  Pressing Esc aborts command entry.

.*s 2 "Dialing Directory"

ECU provides an on-line editable dialing directory.  Remote
systems are defined as records using alphanumeric identifiers
as keys.  Other record fields include telephone number, baud
rate, parity and textual description.

Other features include changing to alternate dialing directory
and a multi-number redial cycle function. Refer below to the description
of the interactive
.B dial
command.

While a long entry in a field may be truncated on the display,
when the entry is edited, it's full contents will be dispalyed on the
edit subform.

Entering or editing a dialing directory entry is for the most part
straightforward.  A note on the use of the "tty" field is useful, however.
When prompted for a tty, you may choose
.BL
.LI
"Any" line  (deprecated, for compatibility only)
.LI
a tty line matching a Devices type
.LI
a specific tty line
.LE

A specific line is chosen by using the base name of the tty
(e.g., "tty1a" or "acu0").  On SCO, since ttys are all named
consistently according to the "/dev/ttyxx" form, you may omit the "tty"
(e.g., "1a" or "4g").  This latter feature is for compatibility
with earlier revisions of ECU.  It is good practice to fully
specify the tty name.

"Any" matches any tty line in the /usr/lib/Devices file supporting
the specified baud rate and whose Devices type begins with the
characters (case independent) "ACU".  This choice is provided to
be compatible with earlier versions of ECU (prior to 3.10). 
Use of this argument is discouraged.  It's equivalent in current
practice is "/ACU", as you can see next.

A more general choice for choosing a tty line based on Devices type
is the "Devices type matching" choice, invoked by prefixing the tty
field with a slash or equals sign.

.BL
.LI
/ prefix searches for a Devices type matching a regular expression (a
la sed or ed)
.LI
= prefix searches for an exact match on a Devices type
.LE

.DS L
Examples:

   =ACU        matches "ACU", fails on "acu" and "ACUx"
   /.*tbit.*   matches "ACUtbit1", "tbit"
.DE

A specific tty line may also be specified.  This is the only means
of attaching a line not mentioned in the Devices file.

NOTE:  If the bell rings and you are not allowed to leave a field,
it is because you MUST enter acceptible data before you can leave
a field using other than the ESCape key.

The "debug level" parameter allows you to specify a number between 0 and
9 for passing to a UUCP dialer program with the -x switch.

The "DCD watch" parameter allows you to modify the DCD watcher
upon successful connection to a remote.  The values allowed are:
.DS L
   1    enable DCD watcher
   0    disable DCD watcher
   t    terminate ECU on loss of DCD
   n    no change of dcdwatch state
.DE
Specifying 'n' leaves the dcdwatch state unaffected.  See the description
of the
.B dcdwatch
interactive command for more information.

The following sample dialing directory screen shows an edit in
progress.

.DS L
 .--[ dialing directory ]-- /u1/wht/.ecu/phone --------- modified ---.
 | entry name | telephone number | tty | baud P | description        |
 | ......     | ........         |Any  | 2400 N | ...............    |
 | li.--[ entry: new ]--------------------------------------------.  |
 | ..|                                                            |  |
 | ..| telephone number  1(800)555-1212                           |  |
 | ..| device            =ACUtbit                                 |..|
 | ..| baud rate         19200                                    |..|
 | ..| parity            N                                        |  |
 | ..| description       don't call this_________________________ |..|
 | ..| debug level       0  (dialer -x value 0-9)                 |  |
 | ..| DCD watch         n                                        |  |
 | ..| Enter description                                          |..|
 | ..| ESC: abort  End: finish  ^U: erase ^B: back  TAB: fwd      |  |
 | ..`------------------------------------------------------------'  |
 | .....      | ..........       |2b   | 9600 N | ...................|
 | sco19      | 1(408)426-9525p  |2b   | 9600 N | SCO Tech Services  |
 | sco24      | 1(408)426-9495   |2b   | 2400 N | SCO Tech Services  |
 +-------------------------------------------------------------------+
 |down up edit add remove save find change dial dir ENTER:dial quit  |
 |redial: mark unMark Unmark all wait between dial                   |
 `-------------------------------------------------------------------'
.DE

You may use the vi conventions of 'j' for down and 'k' for up.
You may also use the up and down arrow keys if you are on an SCO
multiscreen or if the function keys have been properly defined
with funckeymap.