CURSES_TTY(3)

CURSES_TTY(3) | Library Functions Manual | CURSES_TTY(3)

# NAME

`curses_tty`, `baudrate`, `beep`, `flash`, `curs_set`, `def_prog_mode`, `reset_prog_mode`, `def_shell_mode`, `reset_shell_mode`, `echo`, `noecho`, `delay_output`, `erasechar`, `flushinp`, `gettmode`, `halfdelay`, `has_ic`, `has_il`, `idcok`, `idlok`, `intrflush`, `noqiflush`, `qiflush`, `killchar`, `meta`, `napms`, `nl`, `nonl`, `cbreak`, `nocbreak`, `raw`, `noraw`, `typeahead`, `savetty`, `resetty` —
curses terminal manipulation routines

# LIBRARY

Curses Library (libcurses, -lcurses)

# SYNOPSIS

`#include <curses.h>`

int
`baudrate`(void);

int
`beep`(void);

int
`flash`(void);

int
`curs_set`(int visibility);

int
`def_prog_mode`(void);

int
`reset_prog_mode`(void);

int
`def_shell_mode`(void);

int
`reset_shell_mode`(void);

int
`echo`(void);

int
`noecho`(void);

int
`delay_output`(int ms);

char
`erasechar`(void);

int
`flushinp`(void);

int
`gettmode`(void);

bool
`has_ic`(void);

bool
`has_il`(void);

int
`idcok`(WINDOW *win, bool flag);

int
`idlok`(WINDOW *win, bool flag);

int
`intrflush`(WINDOW *win, bool flag);

void
`noqiflush`(void);

void
`qiflush`(void);

char
`killchar`(void);

int
`meta`(WINDOW *win, bool flag);

int
`napms`(int ms);

int
`nl`(void);

int
`nonl`(void);

int
`cbreak`(void);

int
`nocbreak`(void);

int
`halfdelay`(int);

int
`raw`(void);

int
`noraw`(void);

int
`typeahead`(int filedes);

int
`savetty`(void);

int
`resetty`(void);

# DESCRIPTION

These functions manipulate curses terminal settings.

The `baudrate`() function extracts the output speed of the terminal and returns it in bits per second.

The `beep`() function rings the terminal bell, if this is possible. Failing that, the terminal screen will be flashed. If neither of these are possible, then no action will be taken. `flash`() will flash the terminal screen if possible. Failing that, the terminal bell will be rung. If neither of these are possible then no action will be taken.

The cursor visibility can be set by calling `curs_set`(). The following visibility settings are valid for `curs_set`():

Visibility
  Effect
0
  cursor is invisible.
1
  cursor is normal visibility
2
  cursor is high visibility

A successful call to `curs_set`() will return the previous visibility setting for the cursor.

The `delay_output`() function pauses the output to the terminal by sending the appropriate number of terminal pad characters such that the transmission time of the pad characters will take ms milliseconds.

Calling `def_prog_mode`() will cause the current terminal curses setting to be saved. A subsequent call to `reset_prog_mode`(), will restore the saved settings. This is useful when calls to external programs are made that may reset the terminal characteristics.

The `def_shell_mode`() function saves the current terminal line settings. These settings are the ones that will be restored when the curses application exits. Conversely, `reset_shell_mode`() will save the current terminal curses settings for later restoration and restores the previously saved terminal line settings.

The `echo`() function turns on curses echo mode, characters entered will be echoed to the terminal by curses. The `noecho`() function disables this feature.

The current erase character for the terminal can be determined by calling the `erasechar`() function.

The `flushinp`() function discards any pending input for the current screen.

The modes for the current terminal can be reset by calling `gettmode`(), this will perform the initialisation on the terminal that is normally done by curses at start up.

The `has_ic`() function returns either `TRUE` or `FALSE` depending on whether or not the terminal has a insert character capability or not. Similarly the `has_il`() function does the same test but for a insert line capability.

The use of the insert character capability in curses operations can be enabled or disabled by calling `idcok`() on the desired window. Similarly, the use of the insert line capability can be controlled using the `idlok`() function.

The `intrflush`() function controls whether or not a flush of the input buffer is performed when an interrupt key (kill, suspend or quit) is pressed. The win parameter is ignored. The `noqiflush`() function is equivalent to `intrflush`(stdscr, FALSE). The `qiflush`() function is equivalent to `intrflush`(stdscr, TRUE).

The character that performs the line kill function can be determined by calling the `killchar`() function.

The `meta`() function turns on and off the generation of 8 bit characters by the terminal, if flag is `FALSE` then only 7 bit characters will be returned, if flag is `TRUE` then 8 bit characters will be returned by the terminal.

The `napms`() causes the application to sleep for the number of milliseconds specified by ms.

Calling `nl`() will cause curses to map all carriage returns to newlines on input, this functionality is enabled by default. The `nonl`() function disables this behaviour.

The `cbreak`() function will put the terminal into cbreak mode, which means that characters will be returned one at a time instead of waiting for a newline character, line discipline processing will be performed. The `nocbreak`() function disables this mode.

Calling `halfdelay`() puts the terminal into the same mode as `cbreak`() with the exception that if no character is received within the specified number of tenths of a second then the input routine will return `ERR`. This mode can be cancelled by calling `nocbreak`(). The valid range for the timeout is from 1 to 255 tenths of a second.

The `noraw`() function sets the input mode for the current terminal into Cooked mode, that is input character translation and signal character processing is performed. The `raw`() function puts the terminal into Raw mode, no input character translation is done nor is signal character processing.

The `typeahead`() function controls the detection of typeahead during a refresh based on the value of filedes:

- If filedes is a valid file descriptor, typeahead is enabled during refresh; Curses periodically checks filedes for input and aborts the refresh if any character is available. The value of filedes need not be the file descriptor on which the refresh is occurring.
- If filedes is -1, Curses does not check for typeahead during refresh.

The terminal tty flags can be saved by calling `savetty`() and may be restored by calling `resetty`(), the use of these functions is discouraged as they may cause the terminal to be put into a state that is incompatible with curses operation.

# RETURN VALUES

Functions returning pointers will return `NULL` if an error is detected. The functions that return an int will return one of the following values:

`OK`
  The function completed successfully.
`ERR`
  An error occurred in the function.

# SEE ALSO

getch(3), termios(4)

# NOTES

The `idcok`() and `idlok`() currently have no effect on the curses code at all, currently curses will always use the terminal insert character and insert line capabilities if available.

# STANDARDS

The NetBSD Curses library complies with the X/Open Curses specification, part of the Single Unix Specification.

# HISTORY

The Curses package appeared in 4.0BSD.

February 17, 2017 | NetBSD 9.5