# s3270 Manual Page

## Contents

> Name
> Synopsis
> Description
> Options
> Character Sets
> NVT (ANSI) Mode
> Toggles
> Actions
> File Transfer
> Nested Scripts
> Passthru
> Resources
> Files
> See Also
> Copyrights
> Version

## Name

s3270 - IBM host access tool

## Synopsis

s3270 [options] [host]

## Description

s3270 opens a telnet connection to an IBM host, then allows a script to control the host login session. It is derived from x3270(1), an X-windows IBM 3270 emulator. It implements RFCs 2355 (TN3270E), 1576 (TN3270) and 1646 (LU name selection), and supports IND$FILE file transfer.

The full syntax for host is:

> [prefix:]...[LUname@]hostname[:port]

Prepending a P: onto hostname causes the connection to go through the telnet-passthru service rather than directly to the host. See PASSTHRU below.

Prepending an S: onto hostname removes the "extended data stream" option reported to the host. See -tn below for further information.

Prepending an N: onto hostname turns off TN3270E support for the session.

Prepending an L: onto hostname causes s3270 to first create an SSL tunnel to the host, and then create a TN3270 session inside the tunnel. (This function is supported only if s3270 was built with SSL/TLS support). Note that TLS-encrypted sessions using the TELNET START-TLS option are negotiated with the host automatically; for these sessions the L: prefix should not be used.

A specific LU name to use may be specified by prepending it to the hostname with an `@'. Multiple LU names to try can be separated by commas. An empty LU can be placed in the list with an extra comma.

The hostname may optionally be placed inside square-bracket characters `[' and `]'. This will prevent any colon `:' characters in the hostname from being interpreted as indicating option prefixes or port numbers. This allows numeric IPv6 addresses to be used as hostnames.

On systems that support the forkpty library call, the hostname may be replaced with -e and a command string. This will cause s3270 to connect to a local child process, such as a shell.

The port to connect to defaults to telnet. This can be overridden with the -port option, or by appending a port to the hostname with a colon `:'. (For compatability with previous versions of s3270 and with tn3270(1), the port may also be specified as a second, separate argument.)

## Options

s3270 understands the following options:

-charset name
  Specifies an EBCDIC host character set. See CHARACTER SETS below.
-clear toggle
  Sets the initial value of toggle to false. The list of toggle names is under TOGGLES below.
-im method
  Specifies the name of the input method to use for multi-byte input. (Supported only when s3270 is compiled with DBCS support.)
-km name
  Specifies the local encoding method for multi-byte text. name is an encoding name recognized by the ICU library. (Supported only when s3270 is compiled with DBCS support, and necessary only when s3270 cannot figure it out from the locale.)
-model name
  The model of 3270 display to be emulated. The model name is in two parts, either of which may be omitted:

  The first part is the base model, which is either 3278 or 3279. 3278 specifies a monochrome 3270 display; 3279 specifies a color 3270 display.

  The second part is the model number, which specifies the number of rows and columns. Model 4 is the default.

  Model Number | Columns | Rows
  2 | 80 | 24
  3 | 80 | 30
  4 | 80 | 43
  5 | 132 | 27

  Note: Technically, there is no such 3270 display as a 3279-4 or 3279-5, but most hosts seem to work with them anyway.

  The default model is 3278-4.

-mono
  Forces 3278 emulation.
-oversize cols x rows
  Makes the screen larger than the default for the chosen model number. This option has effect only in combination with extended data stream support (controlled by the "s3270.extended" resource), and only if the host supports the Query Reply structured field. The number of columns multiplied by the number of rows must not exceed 16383 (3fff hex), the limit of 14-bit 3270 buffer addressing.
-port n
  Specifies a different TCP port to connect to. n can be a name from /etc/services like telnet, or a number. This option changes the default port number used for all connections. (The positional parameter affects only the initial connection.)
-set toggle
  Sets the initial value of toggle to true. The list of toggle names is under TOGGLES below.
-tn name
  Specifies the terminal name to be transmitted over the telnet connection. The default name is IBM-model_name-E, for example, IBM-3278-4-E.

  Some hosts are confused by the -E suffix on the terminal name, and will ignore the extra screen area on models 3, 4 and 5. Prepending an s: on the hostname, or setting the "s3270.extended" resource to "false", removes the -E from the terminal name when connecting to such hosts.

  The name can also be specified with the "s3270.termName" resource.

-trace
  Turns on data stream and event tracing at startup. The default trace file name is /tmp/x3trc.process_id.
-tracefile file
  Specifies a file to save data stream and event traces into, overriding the default of /tmp/x3trc.process_id.
-tracefilesize size
  Places a limit on the size of a trace file. If this option is not specified, or is specified as 0 or none, the trace file will be unlimited. If specified, the trace file cannot already exist, and the (silently enforced) minimum size is 64 Kbytes. The value of size can have a K or M suffix, indicating kilobytes or megabytes respectively.
-xrm "s3270.resource: value"
  Sets the value of the named resource to value. Resources control less common s3270 options, and are defined under RESOURCES below.

## Character Sets

The -charset option or the "s3270.charset" resource controls the EBCDIC host character set used by s3270. Available sets include:

Charset Name | Code Page | Display Character Sets
apl | 37 | 3270cg-1a
belgian | 500 | 3270cg-1a 3270-cg1 iso8859-1
bracket | 37 | 3270cg-1a 3270-cg1 iso8859-1
brazilian | 275 | 3270cg-1a 3270-cg1 iso8859-1
finnish | 278 | 3270cg-1a 3270-cg1 iso8859-1
french | 297 | 3270cg-1a 3270-cg1 iso8859-1
german | 273 | 3270cg-1a 3270-cg1 iso8859-1
icelandic | 871 | 3270cg-1a 3270-cg1 iso8859-1
iso-hebrew | 424 | iso8859-8
iso-turkish | 1026 | iso8859-9
italian | 280 | 3270cg-1a 3270-cg1 iso8859-1
japanese | 1027+300 | jisx0201.1976-0 + jisx0208.1983-0
norwegian | 277 | 3270cg-1a 3270-cg1 iso8859-1
russian | 880 | koi8-r
simplified-chinese | 836+837 | 3270cg-1a iso8859-1 + gb2312.1980-0
slovenian | 870 | iso8859-2
thai | 838 | iso8859-11 tis620.2529-0
uk | 285 | 3270cg-1a 3270-cg1 iso8859-1
us-intl | 37 | 3270cg-1a 3270-cg1 iso8859-1

The default character set is bracket, which is useful for common IBM hosts which use EBCDIC codes 0xAD and 0xBD for the `[' and `]' characters, respectively.

## NVT (ANSI) Mode

Some hosts use an ASCII front-end to do initial login negotiation, then later switch to 3270 mode. s3270 will emulate an ANSI X.64 terminal until the host places it in 3270 mode (telnet BINARY and SEND EOR modes, or TN3270E mode negotiation).

If the host later negotiates to stop functioning in 3270 mode, s3270 will return to ANSI emulation.

In NVT mode, s3270 supports both character-at-a-time mode and line mode operation. You may select the mode with a menu option. When in line mode, the special characters and operational characteristics are defined by resources:

Mode/Character | Resource | Default
Translate CR to NL | s3270.icrnl | true
Translate NL to CR | s3270.inlcr | false
Erase previous character | s3270.erase | ^?
Erase entire line | s3270.kill | ^U
Erase previous word | s3270.werase | ^W
Redisplay line | s3270.rprnt | ^R
Ignore special meaning of next character | s3270.lnext | ^V
Interrupt | s3270.intr | ^C
Quit | s3270.quit | ^\
End of file | s3270.eof | ^D

## Toggles

s3270 has a number of configurable modes which may be selected by the -set and -clear options.

monoCase
  If set, s3270 operates in uppercase-only mode.
blankFill
  If set, s3270 behaves in some un-3270-like ways. First, when a character is typed into a field, all nulls in the field to the left of that character are changed to blanks. This eliminates a common 3270 data-entry surprise. Second, in insert mode, trailing blanks in a field are treated like nulls, eliminating the annoying `lock-up' that often occurs when inserting into an field with (apparent) space at the end.
lineWrap
  If set, the ANSI terminal emulator automatically assumes a NEWLINE character when it reaches the end of a line.

The names of the toggles for use with the -set and -clear options are as follows:

Option | Name
Monocase | monoCase
Blank Fill | blankFill
Track Cursor | cursorPos
Trace Data Stream | dsTrace
Trace Events | eventTrace
Save Screen(s) in File | screenTrace
Wraparound | lineWrap

These names are also used as the first parameter to the Toggle action.

## Actions

Here is a complete list of basic s3270 actions. Script-specific actions are described on the x3270-script(1) manual page.

Actions marked with an asterisk (*) may block, sending data to the host and possibly waiting for a response.

*Attn | attention key
BackSpace | move cursor left (or send ASCII BS)
BackTab | tab to start of previous input field
CircumNot | input "^" in NVT mode, or "¬" in 3270 mode
*Clear | clear screen
*Connect(host) | connect to host
*CursorSelect | Cursor Select AID
Delete | delete character under cursor (or send ASCII DEL)
DeleteField | delete the entire field
DeleteWord | delete the current or previous word
*Disconnect | disconnect from host
Down | move cursor down
Dup | duplicate field
*Enter | Enter AID (or send ASCII CR)
Erase | erase previous character (or send ASCII BS)
EraseEOF | erase to end of current field
EraseInput | erase all input fields
Execute(cmd) | execute a command in a shell
FieldEnd | move cursor to end of field
FieldMark | mark field
HexString(hex_digits) | insert control-character string
Home | move cursor to first input field
Insert | set insert mode
*Interrupt | send TELNET IP to host
Key(keysym) | insert key keysym
Key(0xxx) | insert key with ASCII code xx
Left | move cursor left
Left2 | move cursor left 2 positions
MonoCase | toggle uppercase-only mode
MoveCursor(row, col) | move cursor to (row,col)
Newline | move cursor to first field on next line (or send ASCII LF)
NextWord | move cursor to next word
*PA(n) | Program Attention AID (n from 1 to 3)
*PF(n) | Program Function AID (n from 1 to 24)
PreviousWord | move cursor to previous word
Quit | exit s3270
Redraw | redraw window
Reset | reset locked keyboard
Right | move cursor right
Right2 | move cursor right 2 positions
*Script(command[,arg...]) | run a script
*String(string) | insert string (simple macro facility)
*SysReq | System Request AID
Tab | move cursor to next input field
Toggle(option[,set|clear]) | toggle an option
ToggleInsert | toggle insert mode
ToggleReverse | toggle reverse-input mode
*Transfer(option=value...) | file transfer
Up | move cursor up

## File Transfer

The Transfer action implements IND$FILE file transfer. This action requires that the IND$FILE program be installed on the IBM host, and that the 3270 cursor be located in a field that will accept a TSO or VM/CMS command.

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.

## Nested Scripts

There are several types of nested script functions available.

The String Action
  The simplest method for nested scripts is provided via the String action. The arguments to String are one or more double-quoted strings which are inserted directly as if typed. The C backslash conventions are honored as follows. (Entries marked * mean that after sending the AID code to the host, s3270 will wait for the host to unlock the keyboard before further processing the string.)

  \b | Left
  \f | Clear*
  \n | Enter*
  \pan | PA(n)*
  \pfnn | PF(nn)*
  \r | Newline
  \t | Tab
  \T | BackTab

  Note: The strings are in ASCII and converted to EBCDIC, so beware of inserting control codes.

  There is also an alternate form of the String action, HexString, which is used to enter non-printing data. The argument to HexString is a string of hexadecimal digits, two per character. A leading 0x or 0X is optional. In 3270 mode, the hexadecimal data represent EBCDIC characters, which are entered into the current field. In NVT mode, the hexadecimal data represent ASCII characters, which are sent directly to the host.

The Script Action
  This action causes s3270 to start a child process which can execute s3270 actions. Standard input and output from the child process are piped back to s3270. The Script action is fully documented in x3270-script(1).

## Passthru

s3270 supports the Sun telnet-passthru service provided by the in.telnet-gw server. This allows outbound telnet connections through a firewall machine. When a p: is prepended to a hostname, s3270 acts much like the itelnet(1) command. It contacts the machine named internet-gateway at the port defined in /etc/services as telnet-passthru (which defaults to 3514). It then passes the requested hostname and port to the in.telnet-gw server.

## Resources

Certain s3270 options can be configured via resources. Resources are defined by -xrm options. The definitions are similar to X11 resources, and use a similar syntax. The resources available in s3270 are:

Resource | Default | Option | Purpose
blankFill | False | -set blankFill | Blank Fill mode
charset | bracket | -charset | EBCDIC character set
charset.foo |  |  | Definition of character set foo
dsTrace | False | -trace | Data stream tracing
eof | ^D |  | NVT-mode EOF character
erase | ^H |  | NVT-mode erase character
extended | True |  | Use 3270 extended data stream
eventTrace | False | -trace | Event tracing
ftCommand | ind$file |  | Host file transfer command
icrnl | False |  | Map CR to NL on NVT-mode input
inlcr | False |  | Map NL to CR in NVT-mode input
intr | ^C |  | NVT-mode interrupt character
kill | ^U |  | NVT-mode kill character
lineWrap | False | -set lineWrap | NVT line wrap mode
lnext | ^V |  | NVT-mode lnext character
m3279 | (note 1) | -mono | 3279 (color) emulation
monoCase | False | -set monoCase | Mono-case mode
numericLock | False |  | Lock keyboard for numeric field error
oerrLock | False |  | Lock keyboard for input error
oversize |  | -oversize | Oversize screen dimensions
port | telnet | -port | Non-default TCP port
quit | ^\ |  | NVT-mode quit character
rprnt | ^R |  | NVT-mode reprint character
secure | False |  | Disable "dangerous" options
termName | (note 2) | -tn | TELNET terminal type string
traceDir | /tmp |  | Directory for trace files
traceFile | (note 3) | -tracefile | File for trace output
werase | ^W |  | NVT-mode word-erase character

> Note 1: m3279 defaults to False. It can be forced to True with the -model option.

> Note 2: The default terminal type string is constructed from the model number, color emulation, and extended data stream modes. E.g., a model 2 with color emulation and the extended data stream option would be sent as IBM-3279-2-E. Note also that when TN3270E mode is used, the terminal type is always sent as some type of 3278.

> Note 3: The default trace file is x3trc.pid in the directory specified by the traceDir resource.

If more than one -xrm option is given for the same resource, the last one on the command line is used.

## Files

/usr/local/lib/x3270/ibm_hosts

## See Also

x3270(1), c3270(1), tcl3270(1), ibm_hosts(5), x3270-script(1), telnet(1), tn3270(1)
Data Stream Programmer's Reference, IBM GA23-0059
Character Set Reference, IBM GA27-3831
RFC 1576, TN3270 Current Practices
RFC 1646, TN3270 Extensions for LUname and Printer Selection
RFC 2355, TN3270 Enhancements

## Copyrights

Modifications Copyright © 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, 2002, 2004 by Paul Mattes.
Original X11 Port Copyright © 1990 by Jeff Sparkes.

> Permission to use, copy, modify, and distribute this software and its documentation for any purpose and without fee is hereby granted, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation.

Copyright © 1989 by Georgia Tech Research Corporation, Atlanta, GA 30332.

> All Rights Reserved. GTRC hereby grants public use of this software. Derivative works based on this software must incorporate this copyright notice.

s3270 is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the file LICENSE for more details.

## Version

s3270 3.3.4