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".

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 connected in unnegotiated mode (no BIND active from the host), the letter P. 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.

12 Command Execution Time

The time that it took for the host to respond to the previous commnd, in seconds with milliseconds after the decimal. If the previous command did not require a host response, this is a dash.

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.)

Normally, the AID actions (Clear, Enter, PF, and PA) 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 proceeding.

The AidWait toggle controls with behavior. When this toggle is set (the default), actions block as described above. When the toggle is clear, AID actions complete immediately. The Wait(Output) action can then be used to delay a script until the host changes something on the screen, and the Wait(Unlock) action can be used to delay a script until the host unlocks the keyboard, regardless of the state of the AidWait toggle.

Note that 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. This behavior is not affected by the state of the AidWait toggle.

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.

PrintText([command,]filter))

Pipes an ASCII representation of the current screen image through the named filter, e.g., lpr.

PrintText([html,],file,filename))

Saves the current screen contents in a file. With the html option, saves it as HTML, otherwise saves it as plain ASCII.

PrintText(html,string)

Returns the current screen contents as HTML.

ReadBuffer(Ascii)

Dumps the contents of the screen buffer, one line at a time. Positions inside data fields are output as 2-digit hexadecimal codes in the current display character set (typically ISO 8859-1, but it varies with the host character set). Start-of-field characters (each of which takes up a display position) are output as SF(aa=nn[,...]), where aa is a field attribute type and nn is its value.

Extended attributes (which do not take up display positions) are output as SA(aa=nn), with aa and nn having the same definitions as above (though the basic 3270 attribute will never appear as an extended attribute).

In addition, NULL characters in the screen buffer are reported as ASCII character 00 instead of 20, even though they should be displayed as blanks.

ReadBuffer(Ebcdic)

Equivalent to Snap(Ascii), but with the data fields output as hexadecimal EBCDIC codes instead. Additionally, if a buffer position has the Graphic Escape attribute, it is displayed as GE(xx).

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(ReadBuffer)

Performs the ReadBuffer 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 indefinitely.

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.

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

For backwards compatibility, Wait(3270) is equivalent to Wait(3270Mode)

Wait([timeout,] Disconnect)

Pauses the script until the host disconnects. Often used to after sending a logoff command to a VM/CMS host, to ensure that the session is not unintentionally set to disconnected state.

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

Wait([timeout,] InputField)

A useful utility for use at the beginning of scripts and after the Connect action. In 3270 mode, waits until the screen is formatted, and the host has positioned the cursor on a modifiable field. In NVT mode, waits until the host sends at least one byte of data.

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

For backwards compatibility, Wait is equivalent to Wait(InputField).

Wait([timeout,] NVTMode)

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

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

For backwards compatibility, Wait(ansi) is equivalent to Wait(NVTMode).

Wait([timeout,] Output)

Pauses the script until the host sends further output. Often needed when the host unlocks the keyboard (allowing the script to proceed after a Clear, Enter, PF or PA action), but has not finished updating the screen. Also used in non-blocking AID mode (see DIFFERENCES for details). This action is usually invoked in a loop that uses the Ascii or 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 Wait action. The default is to wait indefinitely.

Wait([timeout,] Unlock)

Pauses the script until the host unlocks the keyboard. This is useful when operating in non-blocking AID mode (toggle AidWait clear), to wait for a host command to complete. See DIFFERENCES for details).

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

Because of the complexity and number of options for file transfer, the parameters to the Transfer action take the unique form of option=value, and can appear in any order. The options are:

Option	Required?	Default	Other Values
Direction	No	send	receive
HostFile	Yes
LocalFile	Yes
Host	No	tso	vm
Mode	No	ascii	binary
Cr	No	remove	add, keep
Exist	No	keep	replace, append
Recfm	No		fixed, variable, undefined
Lrecl	No
Blksize	No
Allocation	No		tracks, cylinders, avblock
PrimarySpace	No
SecondarySpace	No
BufferSize	No	4096

The option details are as follows.

Direction

send (the default) to send a file to the host, receive to receive a file from the host.

HostFile

The name of the file on the host.

LocalFile

The name of the file on the local workstation.

Host

The type of host (which dictates the form of the IND$FILE command): tso (the default) or vm.

Mode

Use ascii (the default) for a text file, which will be translated between EBCDIC and ASCII as necessary. Use binary for non-text files.

Cr

Controls how Newline characters are handled when transferring Mode=ascii files. remove (the default) strips Newline characters in local files before transferring them to the host. add adds Newline characters to each host file record before transferring it to the local workstation. keep preserves Newline characters when transferring a local file to the host.

Exist

Controls what happens when the destination file already exists. keep (the default) preserves the file, causing the Transfer action to fail. replace overwrites the destination file with the source file. append appends the source file to the destination file.

Recfm

Controls the record of files created on the host. fixed creates a file with fixed-length records. variable creates a file with variable-length records. undefined creates a file with undefined-length records (TSO hosts only). The Lrecl option controls the record length or maximum record length for Recfm=fixed and Recfm=variable files, respectively.

Lrecl

Specifies the record length (or maximum record length) for files created on the host.

Blksize

Specifies the block size for files created on the host. (TSO hosts only.)

Allocation

Specifies the units for the TSO host PrimarySpace and SecondarySpace options: tracks, cylinders or avblock.

PrimarySpace

Primary allocation for a file created on a TSO host. The units are given by the Allocation option.

SecondarySpace

Secondary allocation for a file created on a TSO host. The units are given by the Allocation option.

BufferSize

Buffer size for DFT-mode transfers. Can range from 256 to 32768. Larger values give better performance, but some hosts may not be able to support them.