x3270-script Manual Page

Name
Synopsis
Description
Status Format
Differences
Script-Specific Actions
File Transfer
See Also
Version

Name

Scripting Facilities for x3270, s3270 and c3270

Synopsis

x3270 -script [ x3270-options ]
s3270 [ x3270-options ]
Script ( command [ ,arg... ] )

Description

The x3270 scripting facilities allow the interactive 3270 emulators x3270 and c3270 to be operated under the control of another program, and form the basis for the script-only emulator s3270.

There are two basic scripting methods. The first is the peer script facility, invoked by the x3270 -script switch, and the default mode for s3270. This runs x3270 or s3270 as a child of another process. Typically this would be a script using expect(1), perl(1), or the co-process facility of the Korn Shell ksh(1). Inthis mode, the emulator process looks for commands on its standard input, and places the responses on standard output and standard error output.

The second method is the child script facility, invoked by the Script action in x3270, c3270, or s3270. This runs a script as a child process of the emulator. The child has access to pipes connected to the emulator; the emulator look for commands on one pipe, and places the responses on the other. (The file descriptor of the pipe for commands to the emulator is passed in the environment variable X3270INPUT; the file descriptor of the pipe for responses from the emulator 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, and 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 emulator actions; the syntax is the same as for the right-hand side of an Xt translation table entry (an x3270 or c3270 keymap). Unlike translation tables, action names are case-insensitive, can be uniquely abbreviated, and the parentheses may be omitted if there are no parameters.

Any emulator action may be specified. Several specific actions have been defined for use by scripts, and the behavior of certain other actions (and of the emulators in general) is different 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 the emulator, documented below. If the command is successful, the second line is the string "ok"; otherwise it is the string "error".

Status Format

The status message consists of 11 blank-separated fields:

1 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.
2 Screen Formatting: If the screen is formatted, the letter F. If unformatted or in NVT mode, the letter U.
3 Field Protection: If the field containing the cursor is protected, the letter P. If unprotected or unformatted, the letter U.
4 Connection State: If connected to a host, the string C(hostname). Otherwise, the letter N.
5 Emulator Mode: If connected in 3270 mode, the letter I. If connected in NVT line mode, the letter L. If connected in NVT character mode, the letter C. If not connected, the letter N.
6 Model Number (2-5)
7 Number of Rows: The current number of rows defined on the screen. The host can request that the emulator use a 24x80 screen, so this number may be smaller than the maximum number of rows possible with the current model.
8 Number of Columns: The current number of columns defined on the screen, subject to the same difference for rows, above.
9 Cursor Row: The current cursor row (zero-origin).
10 Cursor Column: The current cursor column (zero-origin).
11 Window ID: The X window identifier for the main x3270 window, in hexadecimal preceded by 0x. For s3270 and c3270, this is zero.

Differences

When an action is initiated by a script, the emulators behave in several different ways:

If an error occurs in processing an ection, 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, the emulator exits. (A script can exit without killing the emulator 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 the emulator to exit. (When called from the keyboard, it will exit only if not connected to a host.)

The Clear, Enter, PF, and PA actions will not complete until the host unlocks the keyboard. If the parameter 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.

Script-Specific 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 NVT mode since the last time that AnsiText 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 NVT mode output in a synchronous manner without trying to decode the screen contents.

Ascii(row,col,rows,cols)

Ascii(row,col,length)

Ascii(length)

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, length characters are output, starting at the specified row and column.

If only the length parameter is given, that many characters 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 the emulator is successfully connected in the proper mode, or the connection fails.

CloseScript(status)

Causes the emulator to stop reading commands from the script. This is useful to allow a peer script to exit, with the emulator proceeding interactively. (Without this command, the emulator 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,length)

Ebcdic(length)

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[,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 NVT 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.

Snap

Equivalent to Snap(Save) (see below).

Snap(Ascii,...)

Performs the Ascii action on the saved screen image.

Snap(Cols)

Returns the number of columns in the saved screen image.

Snap(Ebcdic,...)

Performs the Ebcdic action on the saved screen image.

Snap(Rows)

Returns the number of rows in the saved screen image.

Snap(Save)

Saves a copy of the screen image and status in a temporary buffer. This copy can be queried with other Snap actions to allow a script to examine a consistent screen image, even when the host may be changing the image (or even the screen dimensions) dynamically.

Snap(Status)

Returns the status line from when the screen was last saved.

Snap(Wait[,timeout],Output)

Pauses the script until the host sends further output, then updates the snap buffer with the new screen contents. Used when the host unlocks the keyboard (allowing the script to proceed after an Enter, PF or PA action), but has not finished updating the screen. This action is usually invoked in a loop that uses the Snap(Ascii) or Snap(Ebcdic) action to scan the screen for some pattern that indicates that the host has fully processed the last command.

The optional timeout parameter specifies a number of seconds to wait before failing the Snap action. The default is to wait forever.

Transfer(keyword=value,...)

Invokes IND$FILE file transfer. See FILE TRANSFER below.

Wait([timeout,] 3270Mode)

Used when communicating with a host that switches between NVT mode and 3270 mode. Pauses the script or macro until the host negotiates 3270 mode, then waits for a formatted screen as above.