X3270-SCRIPT(1)
NAME
Scripting Facilities for x3270
SYNOPSIS
x3270 -script [ x3270-options ]
Script( command [ , arg ... ] )
DESCRIPTION
The x3270 scripting facilities allow x3270 to be operated
under the control of another program.
There are two basic methods. The first is the peer script
facility, invoked by the -script switch. This runs x3270
as a child of another process. Typically this would be a
script using expect(1) or the co-process facility of the
Korn Shell ksh(1). When the -script switch is given,
x3270 looks for commands on its standard input, and places
the responses on standard output and standard error out-
put.
The second method is the child script facility, invoked by
the Script() action. This runs a script as a child pro-
cess of x3270. The child has access to pipes connected to
x3270; x3270 looks for commands on one pipe, and places
the responses on the other. (The file descriptor of the
pipe for commands to x3270 is passed in the environment
variable X3270INPUT; the file descriptor of the pipe for
responses from x3270 is passed in the environment variable
X3270OUTPUT.)
(It is possible to mix the two methods: A script can
invoke another script with the Script() action. Scripts
may also be implicitly nested when a script invokes the
Connect() action, and the ibm_hosts file specifies a login
script for that host name.)
Commands are X actions; the syntax is the same as for the
right-hand side of an X translation table (an x3270
keymap), with two exceptions: only one action may appear
per line, and if no parameters are needed by the action,
the parentheses may be omitted.
Any x3270 action may be specified. Several new actions
have been defined for use by scripts, and the behavior of
certain other actions (and of x3270 in general) is differ-
ent when an action is initiated by a script.
Some actions generate output; some may delay completion
until the certain external events occur, such as the host
unlocking the keyboard. The completion of every command
is marked by a two-line message. The first line is the
current status of x3270, documented below. If the command
is successful, the second line is the string "ok"; other-
wise it is the string "error".
STATUS FORMAT
The status message consists of 12 blank-separated fields:
Keyboard State
If the keyboard is unlocked, the letter U. If the
keyboard is locked waiting for a response from the
host, or if not connected to a host, the letter L.
If the keyboard is locked because of an operator
error (field overflow, protected field, etc.), the
letter E.
Screen Formatting
If the screen is formatted, the letter F. If
unformatted or in ANSI mode, the letter U.
Field Protection
If the field containing the cursor is protected,
the letter P. If unprotected or unformatted, the
letter U.
Connection State
If connected to a host, the string C(hostname).
Otherwise, the letter N .
Emulator Mode
If connected in 3270 mode, the letter I. If con-
nected in ANSI line mode, the letter L. If con-
nected in ANSI character mode, the letter C. If
not connected, the letter N.
Model Number (2-5)
Number of Rows
The current number of rows defined on the screen.
The host can request that x3270 use a 24x80 screen,
so this number may be smaller than the maximum num-
ber of rows possible with the current model.
Number of Columns
The current number of columns defined on the
screen, subject to the same difference for rows,
above.
Cursor Row
The current cursor row (zero-origin).
Cursor Column
The current cursor column (zero-origin).
Window ID
The X window identifier for the main x3270 window,
in hexadecimal preceded by 0x.
DIFFERENCES
When an action is initiated by a script, x3270 behaves in
several different ways:
If an error occurs, the usual pop-up window does not
appear. Instead, the text is written to standard error
output.
If end-of-file is detected on standard input, x3270 exits.
(A script can exit without killing x3270 by using the
CloseScript action, below.) Note that this applies to
peer scripts only; end-of-file on the pipe connected to a
child script simply causes the pipes to be closed and the
Script() action to complete.
The Quit() action always causes x3270 to exit. (When
called from the keyboard, it will exit only if not con-
nected to a host.)
The Clear(), Enter(), PF(), and PA() actions will not com-
plete until the host unlocks the keyboard. If the parame-
ter to a String() action includes a code for one these
actions, it will also wait for the keyboard to unlock
before completing. Similarly, the Script() action does
not complete until end-of-file is detected on the pipe or
the CloseScript() action is called by the child process.
NEW ACTIONS
The following actions have been defined or modified for
use with scripts. (Note that unlike the display on the
status line, row and col coordinates used in these actions
use [0,0] as their origin, not [1,1]).
AnsiText()
Outputs whatever data that has been output by the
host in ANSI mode since the last time that Ansi-
Text() was called. The data is preceded by the
string "data: ", and has had all control characters
expanded into C backslash sequences.
This is a convenient way to capture ANSI mode out-
put in a synchronous manner without trying to
decode the screen contents.
Ascii(row,col,rows,cols)
Ascii(row,col,len)
Ascii(len)
Ascii()
Outputs an ASCII text representation of the screen
contents. Each line is preceded by the string
"data: ", and there are no control characters.
If four parameters are given, a rectangular region
of the screen is output.
If three parameters are given, len characters are
output, starting at the specified row and column.
If only the len parameter is given, that many char-
acters are output, starting at the cursor position.
If no parameters are given, the entire screen is
output.
AsciiField()
Outputs an ASCII text representation of the field
containing the cursor. The text is preceded by the
string "data: ".
Connect(hostname)
Connects to a host. The command does not return
until x3270 is successfully connected in the proper
mode, or the connection fails.
CloseScript(status)
Causes x3270 to stop reading commands from the
script. This is useful to allow a peer script to
exit, with x3270 proceeding interactively. (With-
out this command, x3270 would exit when it detected
end-of-file on standard input.) If the script was
invoked by the Script() action, the optional status
is used as the return status of Script(); if
nonzero, Script() will complete with an error, and
if this script was invoked as part of login through
the ibm_hosts file, the connection will be broken.
ContinueScript(param)
Allows a script that is waiting in a PauseScript()
action, below, to continue. The param given is
output by the PauseScript() action.
Disconnect()
Disconnects from the host.
Ebcdic(row,col,rows,cols)
Ebcdic(row,col,len)
Ebcdic(len)
Ebcdic()
The same function as Ascii() above, except that
rather than generating ASCII text, each character
is output as a hexadecimal EBCDIC code, preceded by
0x.
EbcdicField()
The same function as AsciiField() above, except
that it generates hexadecimal EBCDIC codes.
Info(message)
Pops up an informational message.
Expect(text)
Expect(text,timeout)
Pauses the script until the specified text appears
in the data stream from the host, or the specified
timeout (in seconds) expires. If no timeout is
specified, the default is 30 seconds. Text can
contain standard C-language escape (backslash)
sequences. No wild-card characters or pattern
anchor characters are understood. Expect() is
valid only in ANSI mode.
MoveCursor(row,col)
Moves the cursor to the specified coordinates.
PauseScript()
Stops a script until the ContinueScript() action,
above, is executed. This allows a script to wait
for user input and continue. Outputs the single
parameter to ContinueScript().
Wait() A useful utility for use at the beginning of
scripts and after the Connect() action. Waits
until the screen is formatted, and the host has
positioned the cursor on a modifiable field.
SEE ALSO
expect(1)
ksh(1)
x3270(1)