# c3270 Manual Page

## Contents

> Name
> Synopsis
> Description
> Options
> Character Sets
> Hosts Database
> NVT (ANSI) Mode
> Toggles
> Status Line
> Actions
> Keymaps
> The Meta or Alt Key
> File Transfer
> Scripts
> Composite Characters
> Printer Support
> Passthru
> Screen Size Switching
> Resources
> Files
> See Also
> Copyrights
> Version

## Name

c3270 - curses-based IBM host access tool

## Synopsis

c3270 [options] [host]

## Description

c3270 opens a telnet connection to an IBM host in a console window. It implements RFCs 2355 (TN3270E), 1576 (TN3270) and 1646 (LU name selection), and supports IND$FILE file transfer. If the console is capable of displaying colors, then c3270 emulates an IBM 3279. Otherwise, it emulates a 3278.

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 c3270 to first create an SSL tunnel to the host, and then create a TN3270 session inside the tunnel. (This function is supported only if c3270 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 c3270 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 c3270 and with tn3270(1), the port may also be specified as a second, separate argument.)

## Options

c3270 understands the following options:

-allbold
  Forces all characters to be displayed in bold. This helps with PC consoles which display non-bold characters in unreadably dim colors.
-altscreen rows x cols=init_string
  Defines the dimensions and escape sequence for the alternate (132-column) screen mode. See SCREEN SIZE SWITCHING, below.
-cbreak
  Causes c3270 to operate in cbreak mode, instead of raw mode. In cbreak mode, the TTY driver will properly process XOFF and XON characters, which are required by some terminals for proper operation. However, those characters (usually ^S and ^Q), as well as the characters for interrupt, quit, and lnext (usually ^C, ^\ and ^V respectively) will be seen by c3270 only if preceded by the lnext character. The susp character (usually ^Z) cannot be seen by c3270 at all.
-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.
-defscreen rows x cols=init_string
  Defines the dimensions and escape sequence for the default (80-column) screen mode. See SCREEN SIZE SWITCHING, below.
-hostsfile file
  Uses file as the hosts file, which allows aliases for host names and scripts to be executed at login. See ibm_hosts(1) for details.
-im method
  Specifies the name of the input method to use for multi-byte input. (Supported only when c3270 is compiled with DBCS support.)
-keymap name
  Specifies a keyboard map to be found in the resource c3270.keymap.name or the file name. See KEYMAPS below for details.
-km name
  Specifies the local encoding method for multi-byte text. name is an encoding name recognized by the ICU library. (Supported only when c3270 is compiled with DBCS support, and necessary only when c3270 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 for a color display is 3279-4. For a monochrome display, it 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 "c3270.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.)
-printerlu luname
  Causes c3270 to automatically start a pr3287 printer session. If luname is ".", then the printer session will be associated with the interactive terminal session (this requires that the host support TN3270E). Otherwise, the value is used as the explicit LU name to associate with the printer session.
-secure
  Disables the interactive c3270> prompt. When used, a hostname must be provided on the command line.
-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-3279-4-E for a color display, or IBM-3278-4-E for a monochrome display.

  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 "c3270.extended" resource to "false", removes the -E from the terminal name when connecting to such hosts.

  The name can also be specified with the "c3270.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 "c3270.resource: value"
  Sets the value of the named resource to value. Resources control less common c3270 options, and are defined under RESOURCES below.

## Character Sets

The -charset option or the "c3270.charset" resource controls the EBCDIC host character set used by c3270. 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.

## Hosts Database

c3270 uses the ibm_hosts database to define aliases for host names, and to specify macros to be executed when a connection is first made. See ibm_hosts(5) for details.

You may specify a different ibm_hosts database with the "c3270.hostsFile" resource.

## NVT (ANSI) Mode

Some hosts use an ASCII front-end to do initial login negotiation, then later switch to 3270 mode. c3270 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, c3270 will return to ANSI emulation.

In NVT mode, c3270 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 | c3270.icrnl | true
Translate NL to CR | c3270.inlcr | false
Erase previous character | c3270.erase | ^?
Erase entire line | c3270.kill | ^U
Erase previous word | c3270.werase | ^W
Redisplay line | c3270.rprnt | ^R
Ignore special meaning of next character | c3270.lnext | ^V
Interrupt | c3270.intr | ^C
Quit | c3270.quit | ^\
End of file | c3270.eof | ^D

Separate keymaps can be defined for use only when c3270 is in 3270 mode or NVT mode. See KEYMAPS for details.

## Toggles

c3270 has a number of configurable modes which may be selected by the -set and -clear options.

monoCase
  If set, c3270 operates in uppercase-only mode.
blankFill
  If set, c3270 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.

## Status Line

If the terminal that c3270 is running on has at least one more row that the 3270 model requires (e.g., 25 rows for a model 2), c3270 will display a status line. The c3270 status line contains a variety of information. From left to right, the fields are:

comm status
  Three symbols indicate the state of the connection to the host. If connected, the right-hand symbol is a solid box; if not, it is a question mark.
keyboard lock
  If the keyboard is locked, an "X" symbol and a message field indicate the reason for the keyboard lock.
typeahead
  The letter "T" indicates that one or more keystrokes are in the typeahead buffer.
temporary keymap
  The letter "K" indicates that a temporary keymap is in effect.
reverse
  The letter "R" indicates that the keyboard is in reverse field entry mode.
insert mode
  The letter "I" indicates that the keyboard is in insert mode.
printer session
  The letter "P" indicates that a pr3287 session is active.
LU name
  The LU name associated with the session, if there is one.
cursor position
  The cursor row and column are optionally displayed, separated by a "/".

## Actions

Here is a complete list of basic c3270 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
Compose | next two keys form a special symbol
*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
Escape | escape to c3270> prompt
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
Printer(Start[,lu]|Stop) | Start or stop printer session
PrintText(command) | print screen text on printer
Quit | exit c3270
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
ignore | do nothing

Any of the above actions may be entered at the c3270> prompt; these commands are also available for use in keymaps (see KEYMAPS). Command names are case-insensitive. Parameters can be specified with parentheses and commas, e.g.:

> PF(1)

or with spaces, e.g.:

> PF 1

Parameters can be quoted with double-quote characters, to allow spaces, commas, and parentheses to be used.

c3270 also supports the following interactive commands:

Help
  Displays a list of available commands.
Show
  Displays statistics and settings.
Trace
  Turns tracing on or off. The command trace on enables data stream and keyboard event tracing; the command trace off disables it. The qualifier data or keyboard can be specified before on or off to enable or disable a particular trace. After on, a filename may be specified to override the default trace file name of /tmp/x3trc.pid.

## Keymaps

The -keymap option allows a keymap to be specified. If the option -keymap xxx is given, then c3270 will first look for a resource named c3270.keymap.xxx; if that is not found, then it will look for a file named xxx.

Multiple keymaps may be specified be separating their names with commas. Definitions in later keymaps supercede those in earlier keymaps.

In addition, separate keymaps may be defined that apply only in 3270 mode or only in NVT mode. For example, the resource definition c3270.keymap.xxx.nvt will augment the definition of c3270.keymap.xxx, when c3270 is in NVT mode. Similarly, the resource definition c3270.keymap.xxx.3270 will augment the definition of c3270.keymap.xxx, when c3270 is in 3270 mode.

Keymaps specify actions to perform when a particular sequence of keys is pressed. Each line in a keymap has the following syntax:

> [Meta][Ctrl]<Key>key...: Action[(param[,...])] ...

For example:

> Meta<Key>c: Clear()
> <Key>PPAGE: PF(7)
> Ctrl<Key>A <Key>F1: PF(13)

The optional Meta or Ctrl qualifiers specify that the Meta and Ctrl keys are pressed along with the specified key, respectively. The key is either a valid X11 keysym (these are the ISO 8859-1 symbol names, such as equal for `=' and a for `a') or a valid symbolic ncurses key name, such as UP. The Action is an action from the ACTIONS list, above. More than one action may be specified. (Note that symbolic ncurses key names can be used only if the c3270.cursesKeymap resource is set to True, which enables ncurses keymap mode.)

Keymap entries are case-sensitive and modifier-specific. This means that a keymap for the b key will match only a lowercase b. Actions for uppercase B, or for Meta-b or Control-B, must be specified separately.

The base keymap is:

Key | Action
Ctrl<Key>] | Escape
Ctrl<Key>a Ctrl<Key>a | Key(0x01)
Ctrl<Key>a Ctrl<Key>] | Key(0x1d)
Ctrl<Key>a <Key>Tab | BackTab
Ctrl<Key>a <Key>c | Clear
Ctrl<Key>a <Key>e | Escape
Ctrl<Key>a <Key>r | Reset
Ctrl<Key>a <Key>l | Redraw
Ctrl<Key>a <Key>m | Compose
Ctrl<Key>a <Key>^ | Key(notsign)
<Key>UP | Up
<Key>DOWN | Down
<Key>LEFT | Left
<Key>RIGHT | Right
<Key>F(n) | PF(n)
Ctrl<Key>a <Key>F(n) | PF(n+12)
Ctrl<Key>a <Key>1 | PA(1)
Ctrl<Key>a <Key>2 | PA(2)
Ctrl<Key>a <Key>3 | PA(3)

The base 3270-mode keymap adds:

Key | Action
Ctrl<Key>c | Clear
Ctrl<Key>r | Reset
Ctrl<Key>l | Redraw
<Key>Tab | Tab
<Key>DC | Delete
<Key>BACKSPACE | BackSpace
<Key>BackSpace | BackSpace
<Key>Return | Enter
<Key>Linefeed | Newline

## The Meta or Alt Key

Some keyboards do not have a Meta key. Instead, they have an Alt key. Sometimes this key acts as a proper Meta key, that is, it is a modifier key that sets the high-order bit (0x80) in the code that is transmitted for each key. Other keyboards send a two-character sequence when the Alt key is pressed with another key: the Escape character (0x1b), followed by the code for the other key.

The resource c3270.metaEscape and the termcap km attribute control how c3270 will interpret these sequences. When c3270.metaEscape is set to true, or when c3270.metaEscape is set to auto and the termcap km attribute is set, the keyboard is assumed to have a separate Meta key. The Escape key can be used as an ordinary data key and has no special meaning.

When c3270.metaEscape is set to true, or when c3270.metaEscape is set to auto and the termcap km attribute is not set, the keyboard is assumed to use the Escape character as a prefix to indicate that the following character is supposed to have the high-order bit set. When c3270 sees an Escape character from the keyboard, it sets a short timeout. If another character arrives before the timeout expires, then c3270 will combine the two characters, setting the high-order bit of the second. In an event trace file, the combined character is listed as derived. In a keymap, only the combined character or the Meta prefix may be used. The Escape key can still be used by itself, but only if there is a short pause before pressing another key.

The default value for c3270.metaEscape is auto.

## 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.

## Scripts

There are several types of script functions available.

The String Action
  The simplest method for scripting 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, c3270 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

  An example keymap entry would be:

  > Meta<Key>p: String("probs clearrdr\n")

  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 c3270 to start a child process which can execute c3270 actions. Standard input and output from the child process are piped back to c3270. The Script action is fully documented in x3270-script(1).

## Composite Characters

c3270 allows the direct entry of accented letters and special symbols. Pressing and releasing the "Compose" key, followed by two other keys, causes entry of the symbol combining those two keys. For example, "Compose" followed by the "C" key and the "," (comma) key, enters the "C-cedilla" symbol. A C on the status line indicates a pending composite character.

The mappings between these pairs of ordinary keys and the symbols they represent is controlled by the "c3270.composeMap" resource; it gives the name of the map to use. The maps themselves are named "c3270.composeMap.name". The default is "latin1", which gives mappings for most of the symbols in the ISO 8859-1 Latin-1 character set that are not in the 7-bit ASCII character set.

Note: The default keymap defines Meta<Key>m as the "Compose" key. You may set up your own "Compose" key with a keymap that maps some other keysym onto the Compose action.

## Printer Support

c3270 supports associated printer sessions via the pr3287(1) program. The Printer action is used to start or stop a pr3287 session.

The action Printer Start starts a printer session, associated with the current LU. (This works only if the host supports TN3270E.)

The action Printer Start lu starts a printer session, associated with a specific lu.

The action Printer Stop stops a printer session.

The resource c3270.printer.command specifies the command used to print each job; it defaults to lpr. The resource c3270.printer.assocCommandLine specifies the command used to start an associated printer session. It defaults to:

> pr3287 -assoc %L% -command "%C%" %H%

The resource c3270.printer.luCommandLine specifies the command used to start a specific-LU printer session. It defaults to:

> pr3287 -command "%C%" %L%@%H%

When the printer session command is run, the following substitutions are made:

Token | Substitition
%C% | Command (value of c3270.printer.command)
%H% | Host IP address
%L% | Current or specified LU

See pr3287(1) for further details.

## Passthru

c3270 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, c3270 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.

## Screen Size Switching

When running as a 3270 Model 5, c3270 can take advantage of terminals that can switch between 80 and 132 column modes.

Because the curses library does not support mode switching, the escape sequences and resulting screen dimensions must be specified explicitly to c3270. These are specified with the -altscreen and -defscreen command-line options, or the altScreen and defScreen resources. -altscreen or altScreen defines the alternate (132-column) mode; -defscreen or defScreen defines the default (80-column) mode.

The syntax for the options and resources is rows x cols=init_string, where rows and cols give the screen dimensions, and init_string is the escape sequence to transmit to the terminal to enter that mode. For defscreen, the minimum dimensions are 24 rows and 80 columns. For altscreen, the minimum dimensions are 27 rows and 132 columns. Within init_string, the usual escape sequences are supported (\E for escape, \r, \b, etc.). For example, the init string for a 132-column xterm is:

\E[?40h\E[?3h

Note: When defscreen and altscreen are specified, the model number is always set to 5.

## Resources

Certain c3270 options can be configured via resources. Resources are defined in the file .c3270pro in the user's home directory, and by -xrm options. The definitions are similar to X11 resources, and use a similar syntax. The resources available in c3270 are:

Resource | Default | Option | Purpose
allBold | Auto | -allbold | Display all characters bold
altScreen |  | -altscreen | 132-col screen definition
blankFill | False | -set blankFill | Blank Fill mode
charset | bracket | -charset | EBCDIC character set
charset.foo |  |  | Definition of character set foo
composeMap | latin1 |  | Name of composed-character map
cursesKeymap | True |  | Set curses keymap option
defScreen |  | -defscreen | 80-col screen definition
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
hostsFile |  | -hostsfile | Host alias/macro file
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
keymap |  | -keymap | Keyboard map name
keymap.foo |  |  | Definition of keymap foo
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
metaEscape | Auto |  | Interpret ESC-x as Meta-x
monoCase | False | -set monoCase | Mono-case mode
numericLock | False |  | Lock keyboard for numeric field error
oerrLock | True |  | Lock keyboard for input error
oversize |  | -oversize | Oversize screen dimensions
port | telnet | -port | Non-default TCP port
printer.* | (note 4) |  | Printer session config
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
typeahead | True |  | Allow typeahead
werase | ^W |  | NVT-mode word-erase character

> Note 1: m3279 defaults to True if the terminal supports color, False otherwise. It can be forced to False with the -mono 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.

> Note 4: See PRINTER SUPPORT for details.

In .c3270pro, lines are continued with a backslash character.

-xrm options override definitions found in .c3270pro. 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
$HOME/.c3270pro

## See Also

x3270(1), s3270(1), tcl3270(1), ibm_hosts(5), x3270-script(1), pr3287(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.

c3270 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

c3270 3.3.4