2.3 Readline Variables

These variables are available to function writers.

Variable: char * rl_line_buffer

This is the line gathered so far. You are welcome to modify the contents of the line, but see 2.4.5 Allowing Undoing. The function rl_extend_line_buffer is available to increase the memory allocated to rl_line_buffer.

Variable: int rl_point

The offset of the current cursor position in rl_line_buffer (the point).

Variable: int rl_end

The number of characters present in rl_line_buffer. When rl_point is at the end of the line, rl_point and rl_end are equal.

Variable: int rl_mark

The mark (saved position) in the current line. If set, the mark and point define a region.

Variable: int rl_done

Setting this to a non-zero value causes Readline to return the current line immediately.

Variable: int rl_num_chars_to_read

Setting this to a positive value before calling readline() causes Readline to return after accepting that many characters, rather than reading up to a character bound to accept-line.

Variable: int rl_pending_input

Setting this to a value makes it the next keystroke read. This is a way to stuff a single character into the input stream.

Variable: int rl_dispatching

Set to a non-zero value if a function is being called from a key binding; zero otherwise. Application functions can test this to discover whether they were called directly or by Readline's dispatching mechanism.

Variable: int rl_erase_empty_line

Setting this to a non-zero value causes Readline to completely erase the current line, including any prompt, any time a newline is typed as the only character on an otherwise-empty line. The cursor is moved to the beginning of the newly-blank line.

Variable: char * rl_prompt

The prompt Readline uses. This is set from the argument to readline(), and should not be assigned to directly. The rl_set_prompt() function (see section 2.4.6 Redisplay) may be used to modify the prompt string after calling readline().

Variable: int rl_already_prompted

If an application wishes to display the prompt itself, rather than have Readline do it the first time readline() is called, it should set this variable to a non-zero value after displaying the prompt. The prompt must also be passed as the argument to readline() so the redisplay functions can update the display properly. The calling application is responsible for managing the value; Readline never sets it.

Variable: const char * rl_library_version

The version number of this revision of the library.

Variable: int rl_gnu_readline_p

Always set to 1, denoting that this is GNU readline rather than some emulation.

Variable: const char * rl_terminal_name

The terminal type, used for initialization. If not set by the application, Readline sets this to the value of the TERM environment variable the first time it is called.

Variable: const char * rl_readline_name

This variable is set to a unique name by each application using Readline. The value allows conditional parsing of the inputrc file (see section 1.3.2 Conditional Init Constructs).

Variable: FILE * rl_instream

The stdio stream from which Readline reads input.

Variable: FILE * rl_outstream

The stdio stream to which Readline performs output.

Variable: rl_command_func_t * rl_last_func

The address of the last command function Readline executed. May be used to test whether or not a function is being executed twice in succession, for example.

Variable: rl_hook_func_t * rl_startup_hook

If non-zero, this is the address of a function to call just before readline prints the first prompt.

Variable: rl_hook_func_t * rl_pre_input_hook

If non-zero, this is the address of a function to call after the first prompt has been printed and just before readline starts reading input characters.

Variable: rl_hook_func_t * rl_event_hook

If non-zero, this is the address of a function to call periodically when Readline is waiting for terminal input. By default, this will be called at most ten times a second if there is no keyboard input.

Variable: rl_getc_func_t * rl_getc_function

If non-zero, Readline will call indirectly through this pointer to get a character from the input stream. By default, it is set to rl_getc, the default Readline character input function (see section 2.4.8 Character Input).

Variable: rl_voidfunc_t * rl_redisplay_function

If non-zero, Readline will call indirectly through this pointer to update the display with the current contents of the editing buffer. By default, it is set to rl_redisplay, the default Readline redisplay function (see section 2.4.6 Redisplay).

Variable: rl_vintfunc_t * rl_prep_term_function

If non-zero, Readline will call indirectly through this pointer to initialize the terminal. The function takes a single argument, an int flag that says whether or not to use eight-bit characters. By default, this is set to rl_prep_terminal (see section 2.4.9 Terminal Management).

Variable: rl_voidfunc_t * rl_deprep_term_function

If non-zero, Readline will call indirectly through this pointer to reset the terminal. This function should undo the effects of rl_prep_term_function. By default, this is set to rl_deprep_terminal (see section 2.4.9 Terminal Management).

Variable: Keymap rl_executing_keymap

This variable is set to the keymap (see section 2.4.2 Selecting a Keymap) in which the currently executing readline function was found.

Variable: Keymap rl_binding_keymap

This variable is set to the keymap (see section 2.4.2 Selecting a Keymap) in which the last key binding occurred.

Variable: char * rl_executing_macro

This variable is set to the text of any currently-executing macro.

Variable: int rl_readline_state

A variable with bit values that encapsulate the current Readline state. A bit is set with the RL_SETSTATE macro, and unset with the RL_UNSETSTATE macro. Use the RL_ISSTATE macro to test whether a particular state bit is set. Current state bits include:

RL_STATE_NONE

Readline has not yet been called, nor has it begun to intialize.

RL_STATE_INITIALIZING

Readline is initializing its internal data structures.

RL_STATE_INITIALIZED

Readline has completed its initialization.

RL_STATE_TERMPREPPED

Readline has modified the terminal modes to do its own input and redisplay.

RL_STATE_READCMD

Readline is reading a command from the keyboard.

RL_STATE_METANEXT

Readline is reading more input after reading the meta-prefix character.

RL_STATE_DISPATCHING

Readline is dispatching to a command.

RL_STATE_MOREINPUT

Readline is reading more input while executing an editing command.

RL_STATE_ISEARCH

Readline is performing an incremental history search.

RL_STATE_NSEARCH

Readline is performing a non-incremental history search.

RL_STATE_SEARCH

Readline is searching backward or forward through the history for a string.

RL_STATE_NUMERICARG

Readline is reading a numeric argument.

RL_STATE_MACROINPUT

Readline is currently getting its input from a previously-defined keyboard macro.

RL_STATE_MACRODEF

Readline is currently reading characters defining a keyboard macro.

RL_STATE_OVERWRITE

Readline is in overwrite mode.

RL_STATE_COMPLETING

Readline is performing word completion.

RL_STATE_SIGHANDLER

Readline is currently executing the readline signal handler.

RL_STATE_UNDOING

Readline is performing an undo.

RL_STATE_DONE

Readline has read a key sequence bound to accept-line and is about to return the line to the caller.

Variable: int rl_explicit_arg

Set to a non-zero value if an explicit numeric argument was specified by the user. Only valid in a bindable command function.

Variable: int rl_numeric_arg

Set to the value of any numeric argument explicitly specified by the user before executing the current Readline function. Only valid in a bindable command function.

Variable: int rl_editing_mode

Set to a value denoting Readline's current editing mode. A value of 1 means Readline is currently in emacs mode; 0 means that vi mode is active.