• Enhancements made to the curses library to support wide-character format

• Enhancements made to escape sequences used in terminal programming to support drawing of ruled lines

This chapter summarizes the curses functions and macros that process characters and character strings from the screen or keyboard. Tables in each section note if there is more than one curses interface available to perform the same operation, but only one handles wide-character or complex-character format and conforms to the X/Open Curses CAE specification. In such cases, make sure your application uses the curses interface listed in the Recommended Routine column of the table. The Section 3 reference pages provide syntax and detailed information for each interface. Use this chapter to determine the interface needed for the operation you want to do; then use the man or xman command to display the reference page for the chosen interface.

Your choice of interface depends on whether you need to:

• Add the character to the default or a specified window

• Add the character at the current or specified coordinates

• Refresh the screen

Use the cchar_t data type to pass a wide character with its attributes to these interfaces.

• Write to the default or a specified window

• Write at the current or specified coordinates

• Do not advance the position of the cursor

• Do not check the string for special characters (such as newline, tab, and backspace) that usually affect cursor position

• Truncate the string rather than wrapping it around to the next line

Characters in the string that these interfaces add overwrite characters that already exist at the target position. Your choice of interface in this category depends on whether you need to:

• Write all or some of the characters in the string

• Write the characters to the default or a specified window

• Write the characters at the current or specified coordinates

• Advance the position of the cursor

• Check the string for special characters (such as newline, tab, and backspace) that can also affect the position of characters

• Wrap strings to the next line rather than truncating them

Your choice of interface in this category depends on whether you want to:

• Write all or a specified number of characters in the string

• Write the characters to the default or a specified window

• Write the characters at the current or specified coordinates

• Move further to the right any existing characters at and to the right of the target position

  Existing characters are not overwritten, but rightmost characters may be truncated at the end of the line.

• Check the string for special characters (such as newline, tab, and backspace) that can affect character and cursor placement

• Do not advance the cursor after the write operation

Your choice of interface in this category depends on whether you need to:

• Write all or some of the characters in the string

• Write the characters to the default or a specified window

• Write the characters at the current or specified coordinates

Your choice of interface in this category depends on whether you need to:

• Delete a wide character in the default or a specified window

• Delete a wide character at the current or specified coordinates

Your choice of interface in this category depends on whether the character being read is:

• In the default or a specified window

• At the current or specified coordinates

Your choice of interface in this category depends on whether you want to:

• Read all or up to a specified number of wide characters in the string

• Read characters from the default or a specified window

• Read characters that are at the current or specified coordinates

Your choice of interface in this category depends on whether you want to:

• Read all or up to a specified number of characters in the string

• Read characters from the default or a specified window

• Read characters that are at the current or specified coordinates of the window

Your choice of interface in this category depends on whether you want to:

• Read all or up to a specified number of characters in a string

• Read characters for use in the default or a specified window

• Read characters for use at the current or specified coordinates on the window

The unget_wch interface places the wide character at the head of the input queue. In this case, the next call to wget_wch returns the character from the input queue to the program.

Your choice of interface in this category depends on whether you get the character for:

• Use with the default or a specified window

• Use at the current or specified position of the window

• Immediate or delayed use

Your choice of interface in this category depends on whether you:

• Convert a string in the default or a specified window

• Convert a string starting at the current or specified coordinates

• Need to include a list of variables as one of the arguments in the call

Your choice of interface in this category depends on whether you need to:

• Print on the default or a specified window

• Print at the current or a specified position

• Include a list of variables as one of the call arguments

Digital UNIX enhancements for Asian languages include additional escape sequences for drawing and removing ruled lines in a specified area of a DECterm window. These additional escape sequences allow applications to construct tables and diagrams. The feature is a market requirement for Japanese terminals but has been incorporated into DECterm software for all terminal types.

The following sections describe the escape sequences that draw and erase lines according to pattern and area parameters.

When the DECDRLBR escape sequence is received from an application, DECterm software draws ruled lines on one or more of the boundaries of the area between the coordinates(Px,Py ) and(Px+Plx-1, Py+Ply -1) according to the pattern specified in P1. Consider the following example:

CSI 15 ; 1 ; 5 ; 1 ; 2 , r

VT terminals and DECterm software return a primary device attributes report on request from applications. If the extension value 43 is included in this report, drawing ruled lines is enabled for the device. This extension is valid at a level-2 video display or higher. For example, if a DECterm window is emulating a VT382-J terminal, which is the Japanese version of a VT382, the primary device attributes are generated as follows:

CSI ? 63 ; 1 ; 2 ; 4 ; 5 ; 6 ; 7 ; 8 ; 10 ; 15 ; 43 c

Applications can send either the CSI c or CSI 0 c escape sequence to a VT terminal or DECterm software to request a device attributes report.