NAME

Term::ReadLine::readline

DESCRIPTION

Wraps what was initially Perl4 (and now partially Perl4) into a fake Perl5 pseudo-module.

The mismatch of the package name, readline and file name Term::ReadLine::readline was intentional to make is harder to abuse this (very fragile) code...

SUBROUTINES

InitKeyMap

InitKeymap(*keymap, 'default', 'name', bindings...)

_unescape

_unescape($string) -> List of keys

This internal function that takes $string possibly containing escape sequences, and converts to a series of octal keys.

It has special rules for dealing with readline-specific escape-sequence commands.

New-style key bindings are enclosed in double-quotes. Characters are taken verbatim except the special cases:

\C-x    Control x (for any x)
\M-x    Meta x (for any x)
\e      Escape
\*      Set the keymap default   (JP: added this)
        (must be the last character of the sequence)
\x      x  (unless it fits the above pattern)

Special case "\C-\M-x", should be treated like "\M-\C-x".

actually_do_binding

actually_do_binding($function1, \@sequence1, ...)

Actually inserts the binding for @sequence to $function into the current map. @sequence is an array of character ordinals.

If sequence is more than one element long, all but the last will cause meta maps to be created.

$Function will have an implicit F_ prepended to it.

rl_bind

Accepts an array as pairs ($keyspec, $function, [$keyspec, $function]...). and maps the associated bindings to the current KeyMap.

$keyspec should be the name of key sequence in one of two forms:

Old (GNU readline documented) form: M-x to indicate Meta-x C-x to indicate Ctrl-x M-C-x to indicate Meta-Ctrl-x x simple char x

where 'x' above can be a single character, or the special:

special    means
--------   -----
space      space   ( )
spc        space   ( )
tab        tab     (\t)
del        delete  (0x7f)
rubout     delete  (0x7f)
newline    newline (\n)
lfd        newline (\n)
ret        return  (\r)
return     return  (\r)
escape     escape  (\e)
esc        escape  (\e)

New form: "chars" (note the required double-quotes)

where each char in the list represents a character in the sequence, except for the special sequences:

\\C-x         Ctrl-x
\\M-x         Meta-x
\\M-C-x       Meta-Ctrl-x
\\e           escape.
\\x           x (if not one of the above)

$function should be in the form BeginningOfLine or beginning-of-line.

It is an error for the function to not be known....

As an example, the following lines in .inputrc will bind one's xterm arrow keys:

"\e[[A": previous-history
"\e[[B": next-history
"\e[[C": forward-char
"\e[[D": backward-char

read_an_init_file

read_an_init_file(inputrc_file)

Reads and executes inputrc_file which does things like Sets input key bindings in key maps.

If there was a problem return 0. Otherwise return 1;

readline_dumb

A version readline for a dumb terminal, that is one that doesn't have many terminal editing capabilities.

readline

&readline::readline($prompt, $default)

The main routine to call interactively read lines.

$default can be omitted. The next input line is returned or undef on EOF.

ctrl

ctrl($ord)

Returns the ordinal number for the corresponding control code.

For example ctrl(ord('a')) returns the ordinal for Ctrl-A or 1. ctrl(ord('A')) does the same thing.

substr_with_props

substr_with_props($prompt, $string, $from, $len, $ket, $bsel, $esel)

Gives the substr() of $prompt.$string with embedded face-change commands.

redisplay

redisplay()

Updates the screen to reflect the current value if $line.

For the purposes of this routine, we prepend the prompt to a local copy of $line so that we display the prompt as well. We then modify it to reflect that some characters have different sizes. That is, control-C is represented as ^C, tabs are expanded, etc.

This routine is somewhat complicated by two-byte characters.... must make sure never to try do display just half of one.

Note: If an argument is given, it is used instead of the prompt.

This is some nasty code.

get_command

get_command(*keymap, $ord_command_char)

If the *keymap) has an entry for $ord_command_char, it is returned. Otherwise, the default command in $Keymap{'default'} is returned if that exists. If $Keymap{'default'} is false, 'F_Ding' is returned.

do_command

do_command(*keymap, $numericarg, $key)

If the *keymap has an entry for $key, it is executed. Otherwise, the default command for the keymap is executed.

savestate

savestate()

Save whatever state we wish to save as an anonymous array. The only other function that needs to know about its encoding is getstate/preserve_state.

preserve_state

preserve_tate()

F_SelfInsert

F_SelfInsert($count, $ord)

$ord is an ASCII ordinal; inserts $count of them into $line.

F_AcceptLine

Return the line as-is to the user.

add_line_to_history

Insert into history list if:

  • bigger than the minimal length

  • not same as last entry

rl_set

rl_set($var_name, $value_string)

Sets the named variable as per the given value, if both are appropriate. Allows the user of the package to set such things as HorizontalScrollMode and EditingMode. Value_string may be of the form

HorizontalScrollMode
horizontal-scroll-mode

Also called during the parsing of ~/.inputrc for "set var value" lines.

The previous value is returned, or undef on error.

Consider the following example for how to add additional variables accessible via rl_set (and hence via ~/.inputrc).

Want:

We want an external variable called "FooTime" (or "foo-time"). It may have values "January", "Monday", or "Noon". Internally, we'll want those values to translate to 1, 2, and 12.

How:

Have an internal variable $var_FooTime that will represent the current internal value, and initialize it to the default value. Make an array %var_FooTime whose keys and values are are the external (January, Monday, Noon) and internal (1, 2, 12) values:

$var_FooTime = $var_FooTime{'January'} =  1; #default
               $var_FooTime{'Monday'}  =  2;
               $var_FooTime{'Noon'}    = 12;

OnSecondByte

OnSecondByte($index)

Returns true if the byte at $index into $line is the second byte of a two-byte character.

CharSize

CharSize($index)

Returns the size of the character at the given $index in the current line. Most characters are just one byte in length. However, if the byte at the index and the one after both have the high bit set and $_rl_japanese_mb is set, those two bytes are one character of size two.

Assumes that $index points to the first of a 2-byte char if not pointing to a 1-byte char.

TODO: handle Unicode

WordBreak

WordBreak(index)

Returns true if the character at index into $line is a basic word break character, false otherwise.

kill_text

kills from D=$_[0] to $_[1] (to the killbuffer if $_[2] is true)

at_end_of_line

Returns true if $D at the end of the line.

F_ForwardChar

Move forward (right) $count characters.

F_BackwaredChar

Move backward (left) $count characters.

F_BeginningOfLine

Go to beginning of line.

F_EndOfLine

Move to the end of the line.

F_ForwardWord

Move to the end of this/next word. Done as many times as $count says.

F_BackwardWord

Move to the beginning of this/next word. Done as many times as $count says.

F_RedrawCurrentLine

Refresh the input line.

F_ClearScreen

Clear the screen and refresh the line. If given a numeric arg other than 1, simply refreshes the line.

F_QuotedInsert

Insert the next character read verbatim.

F_TabInsert

Insert a tab.

F_OperateAndGetNext

Accept the current line and fetch from the history the next line relative to current line for default.

F_BackwaredDeleteChar

Removes $count chars to left of cursor (if not at beginning of line). If $count > 1, deleted chars saved to kill buffer.

F_DeleteChar

Removes the $count chars from under the cursor. If there is no line and the last command was different, tells readline to return EOF. If there is a line, and the cursor is at the end of it, and we're in tcsh completion mode, then list possible completions. If $count > 1, deleted chars saved to kill buffer.

F_UnixWordRubout

Kill to previous whitespace.

F_UnixLineDiscard

Kill line from cursor to beginning of line.

F_KillLine

delete characters from cursor to end of line.

F_BackwardKillLine

Delete characters from cursor to beginning of line.

TextInsert

TextInsert($count, $string)

F_KillWord

Delete characters to the end of the current word. If not on a word, delete to ## the end of the next word.

F_BackwardKillWord

Delete characters backward to the start of the current word, or, if currently ## not on a word (or just at the start of a word), to the start of the ## previous word.

F_Abort

Abort the current input.

F_DoLowercaseVersion

If the character that got us here is upper case, do the lower-case equivalent command.

F_DoControlVersion

do the equiv with control key... If the character that got us here is upper case, do the lower-case equivalent command.

F_DoMetaVersion

do the equiv with meta key...

F_DoEscVersion

If the character that got us here is Alt-Char, do the Esc Char equiv...

F_Undo

Undo one level.

F_RevertLine

Replace the current line to some "before" state.

F_ViChangeLine

Delete characteres from cursor to end of line and enter VI input mode.