| @comment %**start of header (This is for running Texinfo on a region.) |
| @setfilename rltech.info |
| @comment %**end of header (This is for running Texinfo on a region.) |
| @setchapternewpage odd |
| |
| @ifinfo |
| This document describes the GNU Readline Library, a utility for aiding |
| in the consitency of user interface across discrete programs that need |
| to provide a command line interface. |
| |
| Copyright (C) 1988, 1994, 1996, 1998, 1999 Free Software Foundation, Inc. |
| |
| Permission is granted to make and distribute verbatim copies of |
| this manual provided the copyright notice and this permission notice |
| pare preserved on all copies. |
| |
| @ignore |
| Permission is granted to process this file through TeX and print the |
| results, provided the printed document carries copying permission |
| notice identical to this one except for the removal of this paragraph |
| (this paragraph not being relevant to the printed manual). |
| @end ignore |
| |
| Permission is granted to copy and distribute modified versions of this |
| manual under the conditions for verbatim copying, provided that the entire |
| resulting derived work is distributed under the terms of a permission |
| notice identical to this one. |
| |
| Permission is granted to copy and distribute translations of this manual |
| into another language, under the above conditions for modified versions, |
| except that this permission notice may be stated in a translation approved |
| by the Foundation. |
| @end ifinfo |
| |
| @node Programming with GNU Readline |
| @chapter Programming with GNU Readline |
| |
| This chapter describes the interface between the GNU Readline Library and |
| other programs. If you are a programmer, and you wish to include the |
| features found in GNU Readline |
| such as completion, line editing, and interactive history manipulation |
| in your own programs, this section is for you. |
| |
| @menu |
| * Basic Behavior:: Using the default behavior of Readline. |
| * Custom Functions:: Adding your own functions to Readline. |
| * Readline Variables:: Variables accessible to custom |
| functions. |
| * Readline Convenience Functions:: Functions which Readline supplies to |
| aid in writing your own custom |
| functions. |
| * Readline Signal Handling:: How Readline behaves when it receives signals. |
| * Custom Completers:: Supplanting or supplementing Readline's |
| completion functions. |
| @end menu |
| |
| @node Basic Behavior |
| @section Basic Behavior |
| |
| Many programs provide a command line interface, such as @code{mail}, |
| @code{ftp}, and @code{sh}. For such programs, the default behaviour of |
| Readline is sufficient. This section describes how to use Readline in |
| the simplest way possible, perhaps to replace calls in your code to |
| @code{gets()} or @code{fgets ()}. |
| |
| @findex readline |
| @cindex readline, function |
| The function @code{readline ()} prints a prompt and then reads and returns |
| a single line of text from the user. The line @code{readline} |
| returns is allocated with @code{malloc ()}; you should @code{free ()} |
| the line when you are done with it. The declaration for @code{readline} |
| in ANSI C is |
| |
| @example |
| @code{char *readline (char *@var{prompt});} |
| @end example |
| |
| @noindent |
| So, one might say |
| @example |
| @code{char *line = readline ("Enter a line: ");} |
| @end example |
| @noindent |
| in order to read a line of text from the user. |
| The line returned has the final newline removed, so only the |
| text remains. |
| |
| If @code{readline} encounters an @code{EOF} while reading the line, and the |
| line is empty at that point, then @code{(char *)NULL} is returned. |
| Otherwise, the line is ended just as if a newline had been typed. |
| |
| If you want the user to be able to get at the line later, (with |
| @key{C-p} for example), you must call @code{add_history ()} to save the |
| line away in a @dfn{history} list of such lines. |
| |
| @example |
| @code{add_history (line)}; |
| @end example |
| |
| @noindent |
| For full details on the GNU History Library, see the associated manual. |
| |
| It is preferable to avoid saving empty lines on the history list, since |
| users rarely have a burning need to reuse a blank line. Here is |
| a function which usefully replaces the standard @code{gets ()} library |
| function, and has the advantage of no static buffer to overflow: |
| |
| @example |
| /* A static variable for holding the line. */ |
| static char *line_read = (char *)NULL; |
| |
| /* Read a string, and return a pointer to it. Returns NULL on EOF. */ |
| char * |
| rl_gets () |
| @{ |
| /* If the buffer has already been allocated, return the memory |
| to the free pool. */ |
| if (line_read) |
| @{ |
| free (line_read); |
| line_read = (char *)NULL; |
| @} |
| |
| /* Get a line from the user. */ |
| line_read = readline (""); |
| |
| /* If the line has any text in it, save it on the history. */ |
| if (line_read && *line_read) |
| add_history (line_read); |
| |
| return (line_read); |
| @} |
| @end example |
| |
| This function gives the user the default behaviour of @key{TAB} |
| completion: completion on file names. If you do not want Readline to |
| complete on filenames, you can change the binding of the @key{TAB} key |
| with @code{rl_bind_key ()}. |
| |
| @example |
| @code{int rl_bind_key (int @var{key}, int (*@var{function})());} |
| @end example |
| |
| @code{rl_bind_key ()} takes two arguments: @var{key} is the character that |
| you want to bind, and @var{function} is the address of the function to |
| call when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert ()} |
| makes @key{TAB} insert itself. |
| @code{rl_bind_key ()} returns non-zero if @var{key} is not a valid |
| ASCII character code (between 0 and 255). |
| |
| Thus, to disable the default @key{TAB} behavior, the following suffices: |
| @example |
| @code{rl_bind_key ('\t', rl_insert);} |
| @end example |
| |
| This code should be executed once at the start of your program; you |
| might write a function called @code{initialize_readline ()} which |
| performs this and other desired initializations, such as installing |
| custom completers (@pxref{Custom Completers}). |
| |
| @node Custom Functions |
| @section Custom Functions |
| |
| Readline provides many functions for manipulating the text of |
| the line, but it isn't possible to anticipate the needs of all |
| programs. This section describes the various functions and variables |
| defined within the Readline library which allow a user program to add |
| customized functionality to Readline. |
| |
| Before declaring any functions that customize Readline's behavior, or |
| using any functionality Readline provides in other code, an |
| application writer should include the file @code{<readline/readline.h>} |
| in any file that uses Readline's features. Since some of the definitions |
| in @code{readline.h} use the @code{stdio} library, the file |
| @code{<stdio.h>} should be included before @code{readline.h}. |
| |
| @menu |
| * The Function Type:: C declarations to make code readable. |
| * Function Writing:: Variables and calling conventions. |
| @end menu |
| |
| @node The Function Type |
| @subsection The Function Type |
| |
| For readabilty, we declare a new type of object, called |
| @dfn{Function}. A @code{Function} is a C function which |
| returns an @code{int}. The type declaration for @code{Function} is: |
| |
| @noindent |
| @code{typedef int Function ();} |
| |
| The reason for declaring this new type is to make it easier to write |
| code describing pointers to C functions. Let us say we had a variable |
| called @var{func} which was a pointer to a function. Instead of the |
| classic C declaration |
| |
| @code{int (*)()func;} |
| |
| @noindent |
| we may write |
| |
| @code{Function *func;} |
| |
| @noindent |
| Similarly, there are |
| |
| @example |
| typedef void VFunction (); |
| typedef char *CPFunction (); @r{and} |
| typedef char **CPPFunction (); |
| @end example |
| |
| @noindent |
| for functions returning no value, @code{pointer to char}, and |
| @code{pointer to pointer to char}, respectively. |
| |
| @node Function Writing |
| @subsection Writing a New Function |
| |
| In order to write new functions for Readline, you need to know the |
| calling conventions for keyboard-invoked functions, and the names of the |
| variables that describe the current state of the line read so far. |
| |
| The calling sequence for a command @code{foo} looks like |
| |
| @example |
| @code{foo (int count, int key)} |
| @end example |
| |
| @noindent |
| where @var{count} is the numeric argument (or 1 if defaulted) and |
| @var{key} is the key that invoked this function. |
| |
| It is completely up to the function as to what should be done with the |
| numeric argument. Some functions use it as a repeat count, some |
| as a flag, and others to choose alternate behavior (refreshing the current |
| line as opposed to refreshing the screen, for example). Some choose to |
| ignore it. In general, if a |
| function uses the numeric argument as a repeat count, it should be able |
| to do something useful with both negative and positive arguments. |
| At the very least, it should be aware that it can be passed a |
| negative argument. |
| |
| @node Readline Variables |
| @section Readline Variables |
| |
| These variables are available to function writers. |
| |
| @deftypevar {char *} rl_line_buffer |
| This is the line gathered so far. You are welcome to modify the |
| contents of the line, but see @ref{Allowing Undoing}. The |
| function @code{rl_extend_line_buffer} is available to increase |
| the memory allocated to @code{rl_line_buffer}. |
| @end deftypevar |
| |
| @deftypevar int rl_point |
| The offset of the current cursor position in @code{rl_line_buffer} |
| (the @emph{point}). |
| @end deftypevar |
| |
| @deftypevar int rl_end |
| The number of characters present in @code{rl_line_buffer}. When |
| @code{rl_point} is at the end of the line, @code{rl_point} and |
| @code{rl_end} are equal. |
| @end deftypevar |
| |
| @deftypevar int rl_mark |
| The mark (saved position) in the current line. If set, the mark |
| and point define a @emph{region}. |
| @end deftypevar |
| |
| @deftypevar int rl_done |
| Setting this to a non-zero value causes Readline to return the current |
| line immediately. |
| @end deftypevar |
| |
| @deftypevar 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. |
| @end deftypevar |
| |
| @deftypevar 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. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_prompt |
| The prompt Readline uses. This is set from the argument to |
| @code{readline ()}, and should not be assigned to directly. |
| @end deftypevar |
| |
| @deftypevar int rl_already_prompted |
| If an application wishes to display the prompt itself, rather than have |
| Readline do it the first time @code{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 @code{readline()} so |
| the redisplay functions can update the display properly. |
| The calling application is responsible for managing the value; Readline |
| never sets it. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_library_version |
| The version number of this revision of the library. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_terminal_name |
| The terminal type, used for initialization. |
| @end deftypevar |
| |
| @deftypevar {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 |
| (@pxref{Conditional Init Constructs}). |
| @end deftypevar |
| |
| @deftypevar {FILE *} rl_instream |
| The stdio stream from which Readline reads input. |
| @end deftypevar |
| |
| @deftypevar {FILE *} rl_outstream |
| The stdio stream to which Readline performs output. |
| @end deftypevar |
| |
| @deftypevar {Function *} rl_startup_hook |
| If non-zero, this is the address of a function to call just |
| before @code{readline} prints the first prompt. |
| @end deftypevar |
| |
| @deftypevar {Function *} 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 @code{readline} |
| starts reading input characters. |
| @end deftypevar |
| |
| @deftypevar {Function *} rl_event_hook |
| If non-zero, this is the address of a function to call periodically |
| when readline is waiting for terminal input. |
| @end deftypevar |
| |
| @deftypevar {Function *} rl_getc_function |
| If non-zero, @code{readline} will call indirectly through this pointer |
| to get a character from the input stream. By default, it is set to |
| @code{rl_getc}, the default @code{readline} character input function |
| (@pxref{Utility Functions}). |
| @end deftypevar |
| |
| @deftypevar {VFunction *} rl_redisplay_function |
| If non-zero, @code{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 @code{rl_redisplay}, the default @code{readline} |
| redisplay function (@pxref{Redisplay}). |
| @end deftypevar |
| |
| @deftypevar {Keymap} rl_executing_keymap |
| This variable is set to the keymap (@pxref{Keymaps}) in which the |
| currently executing readline function was found. |
| @end deftypevar |
| |
| @deftypevar {Keymap} rl_binding_keymap |
| This variable is set to the keymap (@pxref{Keymaps}) in which the |
| last key binding occurred. |
| @end deftypevar |
| |
| @node Readline Convenience Functions |
| @section Readline Convenience Functions |
| |
| @menu |
| * Function Naming:: How to give a function you write a name. |
| * Keymaps:: Making keymaps. |
| * Binding Keys:: Changing Keymaps. |
| * Associating Function Names and Bindings:: Translate function names to |
| key sequences. |
| * Allowing Undoing:: How to make your functions undoable. |
| * Redisplay:: Functions to control line display. |
| * Modifying Text:: Functions to modify @code{rl_line_buffer}. |
| * Utility Functions:: Generally useful functions and hooks. |
| * Alternate Interface:: Using Readline in a `callback' fashion. |
| @end menu |
| |
| @node Function Naming |
| @subsection Naming a Function |
| |
| The user can dynamically change the bindings of keys while using |
| Readline. This is done by representing the function with a descriptive |
| name. The user is able to type the descriptive name when referring to |
| the function. Thus, in an init file, one might find |
| |
| @example |
| Meta-Rubout: backward-kill-word |
| @end example |
| |
| This binds the keystroke @key{Meta-Rubout} to the function |
| @emph{descriptively} named @code{backward-kill-word}. You, as the |
| programmer, should bind the functions you write to descriptive names as |
| well. Readline provides a function for doing that: |
| |
| @deftypefun int rl_add_defun (char *name, Function *function, int key) |
| Add @var{name} to the list of named functions. Make @var{function} be |
| the function that gets called. If @var{key} is not -1, then bind it to |
| @var{function} using @code{rl_bind_key ()}. |
| @end deftypefun |
| |
| Using this function alone is sufficient for most applications. It is |
| the recommended way to add a few functions to the default functions that |
| Readline has built in. If you need to do something other |
| than adding a function to Readline, you may need to use the |
| underlying functions described below. |
| |
| @node Keymaps |
| @subsection Selecting a Keymap |
| |
| Key bindings take place on a @dfn{keymap}. The keymap is the |
| association between the keys that the user types and the functions that |
| get run. You can make your own keymaps, copy existing keymaps, and tell |
| Readline which keymap to use. |
| |
| @deftypefun Keymap rl_make_bare_keymap () |
| Returns a new, empty keymap. The space for the keymap is allocated with |
| @code{malloc ()}; you should @code{free ()} it when you are done. |
| @end deftypefun |
| |
| @deftypefun Keymap rl_copy_keymap (Keymap map) |
| Return a new keymap which is a copy of @var{map}. |
| @end deftypefun |
| |
| @deftypefun Keymap rl_make_keymap () |
| Return a new keymap with the printing characters bound to rl_insert, |
| the lowercase Meta characters bound to run their equivalents, and |
| the Meta digits bound to produce numeric arguments. |
| @end deftypefun |
| |
| @deftypefun void rl_discard_keymap (Keymap keymap) |
| Free the storage associated with @var{keymap}. |
| @end deftypefun |
| |
| Readline has several internal keymaps. These functions allow you to |
| change which keymap is active. |
| |
| @deftypefun Keymap rl_get_keymap () |
| Returns the currently active keymap. |
| @end deftypefun |
| |
| @deftypefun void rl_set_keymap (Keymap keymap) |
| Makes @var{keymap} the currently active keymap. |
| @end deftypefun |
| |
| @deftypefun Keymap rl_get_keymap_by_name (char *name) |
| Return the keymap matching @var{name}. @var{name} is one which would |
| be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}). |
| @end deftypefun |
| |
| @deftypefun {char *} rl_get_keymap_name (Keymap keymap) |
| Return the name matching @var{keymap}. @var{name} is one which would |
| be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}). |
| @end deftypefun |
| |
| @node Binding Keys |
| @subsection Binding Keys |
| |
| You associate keys with functions through the keymap. Readline has |
| several internal keymaps: @code{emacs_standard_keymap}, |
| @code{emacs_meta_keymap}, @code{emacs_ctlx_keymap}, |
| @code{vi_movement_keymap}, and @code{vi_insertion_keymap}. |
| @code{emacs_standard_keymap} is the default, and the examples in |
| this manual assume that. |
| |
| Since @code{readline} installs a set of default key bindings the first |
| time it is called, there is always the danger that a custom binding |
| installed before the first call to @code{readline} will be overridden. |
| An alternate mechanism is to install custom key bindings in an |
| initialization function assigned to the @code{rl_startup_hook} variable |
| (@pxref{Readline Variables}). |
| |
| These functions manage key bindings. |
| |
| @deftypefun int rl_bind_key (int key, Function *function) |
| Binds @var{key} to @var{function} in the currently active keymap. |
| Returns non-zero in the case of an invalid @var{key}. |
| @end deftypefun |
| |
| @deftypefun int rl_bind_key_in_map (int key, Function *function, Keymap map) |
| Bind @var{key} to @var{function} in @var{map}. Returns non-zero in the case |
| of an invalid @var{key}. |
| @end deftypefun |
| |
| @deftypefun int rl_unbind_key (int key) |
| Bind @var{key} to the null function in the currently active keymap. |
| Returns non-zero in case of error. |
| @end deftypefun |
| |
| @deftypefun int rl_unbind_key_in_map (int key, Keymap map) |
| Bind @var{key} to the null function in @var{map}. |
| Returns non-zero in case of error. |
| @end deftypefun |
| |
| @deftypefun int rl_unbind_function_in_map (Function *function, Keymap map) |
| Unbind all keys that execute @var{function} in @var{map}. |
| @end deftypefun |
| |
| @deftypefun int rl_unbind_command_in_map (char *command, Keymap map) |
| Unbind all keys that are bound to @var{command} in @var{map}. |
| @end deftypefun |
| |
| @deftypefun int rl_generic_bind (int type, char *keyseq, char *data, Keymap map) |
| Bind the key sequence represented by the string @var{keyseq} to the arbitrary |
| pointer @var{data}. @var{type} says what kind of data is pointed to by |
| @var{data}; this can be a function (@code{ISFUNC}), a macro |
| (@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as |
| necessary. The initial keymap in which to do bindings is @var{map}. |
| @end deftypefun |
| |
| @deftypefun int rl_parse_and_bind (char *line) |
| Parse @var{line} as if it had been read from the @code{inputrc} file and |
| perform any key bindings and variable assignments found |
| (@pxref{Readline Init File}). |
| @end deftypefun |
| |
| @deftypefun int rl_read_init_file (char *filename) |
| Read keybindings and variable assignments from @var{filename} |
| (@pxref{Readline Init File}). |
| @end deftypefun |
| |
| @node Associating Function Names and Bindings |
| @subsection Associating Function Names and Bindings |
| |
| These functions allow you to find out what keys invoke named functions |
| and the functions invoked by a particular key sequence. |
| |
| @deftypefun {Function *} rl_named_function (char *name) |
| Return the function with name @var{name}. |
| @end deftypefun |
| |
| @deftypefun {Function *} rl_function_of_keyseq (char *keyseq, Keymap map, int *type) |
| Return the function invoked by @var{keyseq} in keymap @var{map}. |
| If @var{map} is NULL, the current keymap is used. If @var{type} is |
| not NULL, the type of the object is returned in it (one of @code{ISFUNC}, |
| @code{ISKMAP}, or @code{ISMACR}). |
| @end deftypefun |
| |
| @deftypefun {char **} rl_invoking_keyseqs (Function *function) |
| Return an array of strings representing the key sequences used to |
| invoke @var{function} in the current keymap. |
| @end deftypefun |
| |
| @deftypefun {char **} rl_invoking_keyseqs_in_map (Function *function, Keymap map) |
| Return an array of strings representing the key sequences used to |
| invoke @var{function} in the keymap @var{map}. |
| @end deftypefun |
| |
| @deftypefun void rl_function_dumper (int readable) |
| Print the readline function names and the key sequences currently |
| bound to them to @code{rl_outstream}. If @var{readable} is non-zero, |
| the list is formatted in such a way that it can be made part of an |
| @code{inputrc} file and re-read. |
| @end deftypefun |
| |
| @deftypefun void rl_list_funmap_names () |
| Print the names of all bindable Readline functions to @code{rl_outstream}. |
| @end deftypefun |
| |
| @deftypefun {char **} rl_funmap_names () |
| Return a NULL terminated array of known function names. The array is |
| sorted. The array itself is allocated, but not the strings inside. You |
| should free () the array when you done, but not the pointrs. |
| @end deftypefun |
| |
| @node Allowing Undoing |
| @subsection Allowing Undoing |
| |
| Supporting the undo command is a painless thing, and makes your |
| functions much more useful. It is certainly easy to try |
| something if you know you can undo it. I could use an undo function for |
| the stock market. |
| |
| If your function simply inserts text once, or deletes text once, and |
| uses @code{rl_insert_text ()} or @code{rl_delete_text ()} to do it, then |
| undoing is already done for you automatically. |
| |
| If you do multiple insertions or multiple deletions, or any combination |
| of these operations, you should group them together into one operation. |
| This is done with @code{rl_begin_undo_group ()} and |
| @code{rl_end_undo_group ()}. |
| |
| The types of events that can be undone are: |
| |
| @example |
| enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @}; |
| @end example |
| |
| Notice that @code{UNDO_DELETE} means to insert some text, and |
| @code{UNDO_INSERT} means to delete some text. That is, the undo code |
| tells undo what to undo, not how to undo it. @code{UNDO_BEGIN} and |
| @code{UNDO_END} are tags added by @code{rl_begin_undo_group ()} and |
| @code{rl_end_undo_group ()}. |
| |
| @deftypefun int rl_begin_undo_group () |
| Begins saving undo information in a group construct. The undo |
| information usually comes from calls to @code{rl_insert_text ()} and |
| @code{rl_delete_text ()}, but could be the result of calls to |
| @code{rl_add_undo ()}. |
| @end deftypefun |
| |
| @deftypefun int rl_end_undo_group () |
| Closes the current undo group started with @code{rl_begin_undo_group |
| ()}. There should be one call to @code{rl_end_undo_group ()} |
| for each call to @code{rl_begin_undo_group ()}. |
| @end deftypefun |
| |
| @deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text) |
| Remember how to undo an event (according to @var{what}). The affected |
| text runs from @var{start} to @var{end}, and encompasses @var{text}. |
| @end deftypefun |
| |
| @deftypefun void free_undo_list () |
| Free the existing undo list. |
| @end deftypefun |
| |
| @deftypefun int rl_do_undo () |
| Undo the first thing on the undo list. Returns @code{0} if there was |
| nothing to undo, non-zero if something was undone. |
| @end deftypefun |
| |
| Finally, if you neither insert nor delete text, but directly modify the |
| existing text (e.g., change its case), call @code{rl_modifying ()} |
| once, just before you modify the text. You must supply the indices of |
| the text range that you are going to modify. |
| |
| @deftypefun int rl_modifying (int start, int end) |
| Tell Readline to save the text between @var{start} and @var{end} as a |
| single undo unit. It is assumed that you will subsequently modify |
| that text. |
| @end deftypefun |
| |
| @node Redisplay |
| @subsection Redisplay |
| |
| @deftypefun void rl_redisplay () |
| Change what's displayed on the screen to reflect the current contents |
| of @code{rl_line_buffer}. |
| @end deftypefun |
| |
| @deftypefun int rl_forced_update_display () |
| Force the line to be updated and redisplayed, whether or not |
| Readline thinks the screen display is correct. |
| @end deftypefun |
| |
| @deftypefun int rl_on_new_line () |
| Tell the update functions that we have moved onto a new (empty) line, |
| usually after ouputting a newline. |
| @end deftypefun |
| |
| @deftypefun int rl_on_new_line_with_prompt () |
| Tell the update functions that we have moved onto a new line, with |
| @var{rl_prompt} already displayed. |
| This could be used by applications that want to output the prompt string |
| themselves, but still need Readline to know the prompt string length for |
| redisplay. |
| It should be used after setting @var{rl_already_prompted}. |
| @end deftypefun |
| |
| @deftypefun int rl_reset_line_state () |
| Reset the display state to a clean state and redisplay the current line |
| starting on a new line. |
| @end deftypefun |
| |
| @deftypefun int rl_message (va_alist) |
| The arguments are a string as would be supplied to @code{printf}. The |
| resulting string is displayed in the @dfn{echo area}. The echo area |
| is also used to display numeric arguments and search strings. |
| @end deftypefun |
| |
| @deftypefun int rl_clear_message () |
| Clear the message in the echo area. |
| @end deftypefun |
| |
| @deftypefun void rl_save_prompt () |
| Save the local Readline prompt display state in preparation for |
| displaying a new message in the message area with @code{rl_message}. |
| @end deftypefun |
| |
| @deftypefun void rl_restore_prompt () |
| Restore the local Readline prompt display state saved by the most |
| recent call to @code{rl_save_prompt}. |
| @end deftypefun |
| |
| @node Modifying Text |
| @subsection Modifying Text |
| |
| @deftypefun int rl_insert_text (char *text) |
| Insert @var{text} into the line at the current cursor position. |
| @end deftypefun |
| |
| @deftypefun int rl_delete_text (int start, int end) |
| Delete the text between @var{start} and @var{end} in the current line. |
| @end deftypefun |
| |
| @deftypefun {char *} rl_copy_text (int start, int end) |
| Return a copy of the text between @var{start} and @var{end} in |
| the current line. |
| @end deftypefun |
| |
| @deftypefun int rl_kill_text (int start, int end) |
| Copy the text between @var{start} and @var{end} in the current line |
| to the kill ring, appending or prepending to the last kill if the |
| last command was a kill command. The text is deleted. |
| If @var{start} is less than @var{end}, |
| the text is appended, otherwise prepended. If the last command was |
| not a kill, a new kill ring slot is used. |
| @end deftypefun |
| |
| @node Utility Functions |
| @subsection Utility Functions |
| |
| @deftypefun int rl_read_key () |
| Return the next character available. This handles input inserted into |
| the input stream via @var{pending input} (@pxref{Readline Variables}) |
| and @code{rl_stuff_char ()}, macros, and characters read from the keyboard. |
| @end deftypefun |
| |
| @deftypefun int rl_getc (FILE *) |
| Return the next character available from the keyboard. |
| @end deftypefun |
| |
| @deftypefun int rl_stuff_char (int c) |
| Insert @var{c} into the Readline input stream. It will be "read" |
| before Readline attempts to read characters from the terminal with |
| @code{rl_read_key ()}. |
| @end deftypefun |
| |
| @deftypefun int rl_extend_line_buffer (int len) |
| Ensure that @code{rl_line_buffer} has enough space to hold @var{len} |
| characters, possibly reallocating it if necessary. |
| @end deftypefun |
| |
| @deftypefun int rl_initialize () |
| Initialize or re-initialize Readline's internal state. |
| @end deftypefun |
| |
| @deftypefun int rl_reset_terminal (char *terminal_name) |
| Reinitialize Readline's idea of the terminal settings using |
| @var{terminal_name} as the terminal type (e.g., @code{vt100}). |
| If @var{terminal_name} is NULL, the value of the @code{TERM} |
| environment variable is used. |
| @end deftypefun |
| |
| @deftypefun int alphabetic (int c) |
| Return 1 if @var{c} is an alphabetic character. |
| @end deftypefun |
| |
| @deftypefun int numeric (int c) |
| Return 1 if @var{c} is a numeric character. |
| @end deftypefun |
| |
| @deftypefun int ding () |
| Ring the terminal bell, obeying the setting of @code{bell-style}. |
| @end deftypefun |
| |
| @deftypefun void rl_display_match_list (char **matches, int len, int max) |
| A convenience function for displaying a list of strings in |
| columnar format on Readline's output stream. @code{matches} is the list |
| of strings, in argv format, such as a list of completion matches. |
| @code{len} is the number of strings in @code{matches}, and @code{max} |
| is the length of the longest string in @code{matches}. This function uses |
| the setting of @code{print-completions-horizontally} to select how the |
| matches are displayed (@pxref{Readline Init File Syntax}). |
| @end deftypefun |
| |
| The following are implemented as macros, defined in @code{chartypes.h}. |
| |
| @deftypefun int uppercase_p (int c) |
| Return 1 if @var{c} is an uppercase alphabetic character. |
| @end deftypefun |
| |
| @deftypefun int lowercase_p (int c) |
| Return 1 if @var{c} is a lowercase alphabetic character. |
| @end deftypefun |
| |
| @deftypefun int digit_p (int c) |
| Return 1 if @var{c} is a numeric character. |
| @end deftypefun |
| |
| @deftypefun int to_upper (int c) |
| If @var{c} is a lowercase alphabetic character, return the corresponding |
| uppercase character. |
| @end deftypefun |
| |
| @deftypefun int to_lower (int c) |
| If @var{c} is an uppercase alphabetic character, return the corresponding |
| lowercase character. |
| @end deftypefun |
| |
| @deftypefun int digit_value (int c) |
| If @var{c} is a number, return the value it represents. |
| @end deftypefun |
| |
| @node Alternate Interface |
| @subsection Alternate Interface |
| |
| An alternate interface is available to plain @code{readline()}. Some |
| applications need to interleave keyboard I/O with file, device, or |
| window system I/O, typically by using a main loop to @code{select()} |
| on various file descriptors. To accomodate this need, readline can |
| also be invoked as a `callback' function from an event loop. There |
| are functions available to make this easy. |
| |
| @deftypefun void rl_callback_handler_install (char *prompt, Vfunction *lhandler) |
| Set up the terminal for readline I/O and display the initial |
| expanded value of @var{prompt}. Save the value of @var{lhandler} to |
| use as a callback when a complete line of input has been entered. |
| @end deftypefun |
| |
| @deftypefun void rl_callback_read_char () |
| Whenever an application determines that keyboard input is available, it |
| should call @code{rl_callback_read_char()}, which will read the next |
| character from the current input source. If that character completes the |
| line, @code{rl_callback_read_char} will invoke the @var{lhandler} |
| function saved by @code{rl_callback_handler_install} to process the |
| line. @code{EOF} is indicated by calling @var{lhandler} with a |
| @code{NULL} line. |
| @end deftypefun |
| |
| @deftypefun void rl_callback_handler_remove () |
| Restore the terminal to its initial state and remove the line handler. |
| This may be called from within a callback as well as independently. |
| @end deftypefun |
| |
| @subsection An Example |
| |
| Here is a function which changes lowercase characters to their uppercase |
| equivalents, and uppercase characters to lowercase. If |
| this function was bound to @samp{M-c}, then typing @samp{M-c} would |
| change the case of the character under point. Typing @samp{M-1 0 M-c} |
| would change the case of the following 10 characters, leaving the cursor on |
| the last character changed. |
| |
| @example |
| /* Invert the case of the COUNT following characters. */ |
| int |
| invert_case_line (count, key) |
| int count, key; |
| @{ |
| register int start, end, i; |
| |
| start = rl_point; |
| |
| if (rl_point >= rl_end) |
| return (0); |
| |
| if (count < 0) |
| @{ |
| direction = -1; |
| count = -count; |
| @} |
| else |
| direction = 1; |
| |
| /* Find the end of the range to modify. */ |
| end = start + (count * direction); |
| |
| /* Force it to be within range. */ |
| if (end > rl_end) |
| end = rl_end; |
| else if (end < 0) |
| end = 0; |
| |
| if (start == end) |
| return (0); |
| |
| if (start > end) |
| @{ |
| int temp = start; |
| start = end; |
| end = temp; |
| @} |
| |
| /* Tell readline that we are modifying the line, so it will save |
| the undo information. */ |
| rl_modifying (start, end); |
| |
| for (i = start; i != end; i++) |
| @{ |
| if (uppercase_p (rl_line_buffer[i])) |
| rl_line_buffer[i] = to_lower (rl_line_buffer[i]); |
| else if (lowercase_p (rl_line_buffer[i])) |
| rl_line_buffer[i] = to_upper (rl_line_buffer[i]); |
| @} |
| /* Move point to on top of the last character changed. */ |
| rl_point = (direction == 1) ? end - 1 : start; |
| return (0); |
| @} |
| @end example |
| |
| @node Readline Signal Handling |
| @section Readline Signal Handling |
| |
| Signals are asynchronous events sent to a process by the Unix kernel, |
| sometimes on behalf of another process. They are intended to indicate |
| exceptional events, like a user pressing the interrupt key on his |
| terminal, or a network connection being broken. There is a class of |
| signals that can be sent to the process currently reading input from |
| the keyboard. Since Readline changes the terminal attributes when it |
| is called, it needs to perform special processing when a signal is |
| received to restore the terminal to a sane state, or provide application |
| writers with functions to do so manually. |
| |
| Readline contains an internal signal handler that is installed for a |
| number of signals (@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, |
| @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}). |
| When one of these signals is received, the signal handler |
| will reset the terminal attributes to those that were in effect before |
| @code{readline ()} was called, reset the signal handling to what it was |
| before @code{readline ()} was called, and resend the signal to the calling |
| application. |
| If and when the calling application's signal handler returns, Readline |
| will reinitialize the terminal and continue to accept input. |
| When a @code{SIGINT} is received, the Readline signal handler performs |
| some additional work, which will cause any partially-entered line to be |
| aborted (see the description of @code{rl_free_line_state ()}). |
| |
| There is an additional Readline signal handler, for @code{SIGWINCH}, which |
| the kernel sends to a process whenever the terminal's size changes (for |
| example, if a user resizes an @code{xterm}). The Readline @code{SIGWINCH} |
| handler updates Readline's internal screen size state, and then calls any |
| @code{SIGWINCH} signal handler the calling application has installed. |
| Readline calls the application's @code{SIGWINCH} signal handler without |
| resetting the terminal to its original state. If the application's signal |
| handler does more than update its idea of the terminal size and return (for |
| example, a @code{longjmp} back to a main processing loop), it @emph{must} |
| call @code{rl_cleanup_after_signal ()} (described below), to restore the |
| terminal state. |
| |
| Readline provides two variables that allow application writers to |
| control whether or not it will catch certain signals and act on them |
| when they are received. It is important that applications change the |
| values of these variables only when calling @code{readline ()}, not in |
| a signal handler, so Readline's internal signal state is not corrupted. |
| |
| @deftypevar int rl_catch_signals |
| If this variable is non-zero, Readline will install signal handlers for |
| @code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, @code{SIGALRM}, |
| @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}. |
| |
| The default value of @code{rl_catch_signals} is 1. |
| @end deftypevar |
| |
| @deftypevar int rl_catch_sigwinch |
| If this variable is non-zero, Readline will install a signal handler for |
| @code{SIGWINCH}. |
| |
| The default value of @code{rl_catch_sigwinch} is 1. |
| @end deftypevar |
| |
| If an application does not wish to have Readline catch any signals, or |
| to handle signals other than those Readline catches (@code{SIGHUP}, |
| for example), |
| Readline provides convenience functions to do the necessary terminal |
| and internal state cleanup upon receipt of a signal. |
| |
| @deftypefun void rl_cleanup_after_signal (void) |
| This function will reset the state of the terminal to what it was before |
| @code{readline ()} was called, and remove the Readline signal handlers for |
| all signals, depending on the values of @code{rl_catch_signals} and |
| @code{rl_catch_sigwinch}. |
| @end deftypefun |
| |
| @deftypefun void rl_free_line_state (void) |
| This will free any partial state associated with the current input line |
| (undo information, any partial history entry, any partially-entered |
| keyboard macro, and any partially-entered numeric argument). This |
| should be called before @code{rl_cleanup_after_signal ()}. The |
| Readline signal handler for @code{SIGINT} calls this to abort the |
| current input line. |
| @end deftypefun |
| |
| @deftypefun void rl_reset_after_signal (void) |
| This will reinitialize the terminal and reinstall any Readline signal |
| handlers, depending on the values of @code{rl_catch_signals} and |
| @code{rl_catch_sigwinch}. |
| @end deftypefun |
| |
| If an application does not wish Readline to catch @code{SIGWINCH}, it may |
| call @code{rl_resize_terminal ()} to force Readline to update its idea of |
| the terminal size when a @code{SIGWINCH} is received. |
| |
| @deftypefun void rl_resize_terminal (void) |
| Update Readline's internal screen size. |
| @end deftypefun |
| |
| The following functions install and remove Readline's signal handlers. |
| |
| @deftypefun int rl_set_signals (void) |
| Install Readline's signal handler for @code{SIGINT}, @code{SIGQUIT}, |
| @code{SIGTERM}, @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, |
| @code{SIGTTOU}, and @code{SIGWINCH}, depending on the values of |
| @code{rl_catch_signals} and @code{rl_catch_sigwinch}. |
| @end deftypefun |
| |
| @deftypefun int rl_clear_signals (void) |
| Remove all of the Readline signal handlers installed by |
| @code{rl_set_signals ()}. |
| @end deftypefun |
| |
| @node Custom Completers |
| @section Custom Completers |
| |
| Typically, a program that reads commands from the user has a way of |
| disambiguating commands and data. If your program is one of these, then |
| it can provide completion for commands, data, or both. |
| The following sections describe how your program and Readline |
| cooperate to provide this service. |
| |
| @menu |
| * How Completing Works:: The logic used to do completion. |
| * Completion Functions:: Functions provided by Readline. |
| * Completion Variables:: Variables which control completion. |
| * A Short Completion Example:: An example of writing completer subroutines. |
| @end menu |
| |
| @node How Completing Works |
| @subsection How Completing Works |
| |
| In order to complete some text, the full list of possible completions |
| must be available. That is, it is not possible to accurately |
| expand a partial word without knowing all of the possible words |
| which make sense in that context. The Readline library provides |
| the user interface to completion, and two of the most common |
| completion functions: filename and username. For completing other types |
| of text, you must write your own completion function. This section |
| describes exactly what such functions must do, and provides an example. |
| |
| There are three major functions used to perform completion: |
| |
| @enumerate |
| @item |
| The user-interface function @code{rl_complete ()}. This function is |
| called with the same arguments as other Readline |
| functions intended for interactive use: @var{count} and |
| @var{invoking_key}. It isolates the word to be completed and calls |
| @code{completion_matches ()} to generate a list of possible completions. |
| It then either lists the possible completions, inserts the possible |
| completions, or actually performs the |
| completion, depending on which behavior is desired. |
| |
| @item |
| The internal function @code{completion_matches ()} uses your |
| @dfn{generator} function to generate the list of possible matches, and |
| then returns the array of these matches. You should place the address |
| of your generator function in @code{rl_completion_entry_function}. |
| |
| @item |
| The generator function is called repeatedly from |
| @code{completion_matches ()}, returning a string each time. The |
| arguments to the generator function are @var{text} and @var{state}. |
| @var{text} is the partial word to be completed. @var{state} is zero the |
| first time the function is called, allowing the generator to perform |
| any necessary initialization, and a positive non-zero integer for |
| each subsequent call. When the generator function returns |
| @code{(char *)NULL} this signals @code{completion_matches ()} that there are |
| no more possibilities left. Usually the generator function computes the |
| list of possible completions when @var{state} is zero, and returns them |
| one at a time on subsequent calls. Each string the generator function |
| returns as a match must be allocated with @code{malloc()}; Readline |
| frees the strings when it has finished with them. |
| |
| @end enumerate |
| |
| @deftypefun int rl_complete (int ignore, int invoking_key) |
| Complete the word at or before point. You have supplied the function |
| that does the initial simple matching selection algorithm (see |
| @code{completion_matches ()}). The default is to do filename completion. |
| @end deftypefun |
| |
| @deftypevar {Function *} rl_completion_entry_function |
| This is a pointer to the generator function for @code{completion_matches |
| ()}. If the value of @code{rl_completion_entry_function} is |
| @code{(Function *)NULL} then the default filename generator function, |
| @code{filename_completion_function ()}, is used. |
| @end deftypevar |
| |
| @node Completion Functions |
| @subsection Completion Functions |
| |
| Here is the complete list of callable completion functions present in |
| Readline. |
| |
| @deftypefun int rl_complete_internal (int what_to_do) |
| Complete the word at or before point. @var{what_to_do} says what to do |
| with the completion. A value of @samp{?} means list the possible |
| completions. @samp{TAB} means do standard completion. @samp{*} means |
| insert all of the possible completions. @samp{!} means to display |
| all of the possible completions, if there is more than one, as well as |
| performing partial completion. |
| @end deftypefun |
| |
| @deftypefun int rl_complete (int ignore, int invoking_key) |
| Complete the word at or before point. You have supplied the function |
| that does the initial simple matching selection algorithm (see |
| @code{completion_matches ()} and @code{rl_completion_entry_function}). |
| The default is to do filename |
| completion. This calls @code{rl_complete_internal ()} with an |
| argument depending on @var{invoking_key}. |
| @end deftypefun |
| |
| @deftypefun int rl_possible_completions (int count, int invoking_key)) |
| List the possible completions. See description of @code{rl_complete |
| ()}. This calls @code{rl_complete_internal ()} with an argument of |
| @samp{?}. |
| @end deftypefun |
| |
| @deftypefun int rl_insert_completions (int count, int invoking_key)) |
| Insert the list of possible completions into the line, deleting the |
| partially-completed word. See description of @code{rl_complete ()}. |
| This calls @code{rl_complete_internal ()} with an argument of @samp{*}. |
| @end deftypefun |
| |
| @deftypefun {char **} completion_matches (char *text, CPFunction *entry_func) |
| Returns an array of @code{(char *)} which is a list of completions for |
| @var{text}. If there are no completions, returns @code{(char **)NULL}. |
| The first entry in the returned array is the substitution for @var{text}. |
| The remaining entries are the possible completions. The array is |
| terminated with a @code{NULL} pointer. |
| |
| @var{entry_func} is a function of two args, and returns a |
| @code{(char *)}. The first argument is @var{text}. The second is a |
| state argument; it is zero on the first call, and non-zero on subsequent |
| calls. @var{entry_func} returns a @code{NULL} pointer to the caller |
| when there are no more matches. |
| @end deftypefun |
| |
| @deftypefun {char *} filename_completion_function (char *text, int state) |
| A generator function for filename completion in the general case. Note |
| that completion in Bash is a little different because of all |
| the pathnames that must be followed when looking up completions for a |
| command. The Bash source is a useful reference for writing custom |
| completion functions. |
| @end deftypefun |
| |
| @deftypefun {char *} username_completion_function (char *text, int state) |
| A completion generator for usernames. @var{text} contains a partial |
| username preceded by a random character (usually @samp{~}). As with all |
| completion generators, @var{state} is zero on the first call and non-zero |
| for subsequent calls. |
| @end deftypefun |
| |
| @node Completion Variables |
| @subsection Completion Variables |
| |
| @deftypevar {Function *} rl_completion_entry_function |
| A pointer to the generator function for @code{completion_matches ()}. |
| @code{NULL} means to use @code{filename_completion_function ()}, the default |
| filename completer. |
| @end deftypevar |
| |
| @deftypevar {CPPFunction *} rl_attempted_completion_function |
| A pointer to an alternative function to create matches. |
| The function is called with @var{text}, @var{start}, and @var{end}. |
| @var{start} and @var{end} are indices in @code{rl_line_buffer} saying |
| what the boundaries of @var{text} are. If this function exists and |
| returns @code{NULL}, or if this variable is set to @code{NULL}, then |
| @code{rl_complete ()} will call the value of |
| @code{rl_completion_entry_function} to generate matches, otherwise the |
| array of strings returned will be used. |
| @end deftypevar |
| |
| @deftypevar {CPFunction *} rl_filename_quoting_function |
| A pointer to a function that will quote a filename in an application- |
| specific fashion. This is called if filename completion is being |
| attempted and one of the characters in @code{rl_filename_quote_characters} |
| appears in a completed filename. The function is called with |
| @var{text}, @var{match_type}, and @var{quote_pointer}. The @var{text} |
| is the filename to be quoted. The @var{match_type} is either |
| @code{SINGLE_MATCH}, if there is only one completion match, or |
| @code{MULT_MATCH}. Some functions use this to decide whether or not to |
| insert a closing quote character. The @var{quote_pointer} is a pointer |
| to any opening quote character the user typed. Some functions choose |
| to reset this character. |
| @end deftypevar |
| |
| @deftypevar {CPFunction *} rl_filename_dequoting_function |
| A pointer to a function that will remove application-specific quoting |
| characters from a filename before completion is attempted, so those |
| characters do not interfere with matching the text against names in |
| the filesystem. It is called with @var{text}, the text of the word |
| to be dequoted, and @var{quote_char}, which is the quoting character |
| that delimits the filename (usually @samp{'} or @samp{"}). If |
| @var{quote_char} is zero, the filename was not in an embedded string. |
| @end deftypevar |
| |
| @deftypevar {Function *} rl_char_is_quoted_p |
| A pointer to a function to call that determines whether or not a specific |
| character in the line buffer is quoted, according to whatever quoting |
| mechanism the program calling readline uses. The function is called with |
| two arguments: @var{text}, the text of the line, and @var{index}, the |
| index of the character in the line. It is used to decide whether a |
| character found in @code{rl_completer_word_break_characters} should be |
| used to break words for the completer. |
| @end deftypevar |
| |
| @deftypevar int rl_completion_query_items |
| Up to this many items will be displayed in response to a |
| possible-completions call. After that, we ask the user if she is sure |
| she wants to see them all. The default value is 100. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_basic_word_break_characters |
| The basic list of characters that signal a break between words for the |
| completer routine. The default value of this variable is the characters |
| which break words for completion in Bash, i.e., |
| @code{" \t\n\"\\'`@@$><=;|&@{("}. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_basic_quote_characters |
| List of quote characters which can cause a word break. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_completer_word_break_characters |
| The list of characters that signal a break between words for |
| @code{rl_complete_internal ()}. The default list is the value of |
| @code{rl_basic_word_break_characters}. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_completer_quote_characters |
| List of characters which can be used to quote a substring of the line. |
| Completion occurs on the entire substring, and within the substring |
| @code{rl_completer_word_break_characters} are treated as any other character, |
| unless they also appear within this list. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_filename_quote_characters |
| A list of characters that cause a filename to be quoted by the completer |
| when they appear in a completed filename. The default is the null string. |
| @end deftypevar |
| |
| @deftypevar {char *} rl_special_prefixes |
| The list of characters that are word break characters, but should be |
| left in @var{text} when it is passed to the completion function. |
| Programs can use this to help determine what kind of completing to do. |
| For instance, Bash sets this variable to "$@@" so that it can complete |
| shell variables and hostnames. |
| @end deftypevar |
| |
| @deftypevar {int} rl_completion_append_character |
| When a single completion alternative matches at the end of the command |
| line, this character is appended to the inserted completion text. The |
| default is a space character (@samp{ }). Setting this to the null |
| character (@samp{\0}) prevents anything being appended automatically. |
| This can be changed in custom completion functions to |
| provide the ``most sensible word separator character'' according to |
| an application-specific command line syntax specification. |
| @end deftypevar |
| |
| @deftypevar int rl_ignore_completion_duplicates |
| If non-zero, then disallow duplicates in the matches. Default is 1. |
| @end deftypevar |
| |
| @deftypevar int rl_filename_completion_desired |
| Non-zero means that the results of the matches are to be treated as |
| filenames. This is @emph{always} zero on entry, and can only be changed |
| within a completion entry generator function. If it is set to a non-zero |
| value, directory names have a slash appended and Readline attempts to |
| quote completed filenames if they contain any embedded word break |
| characters. |
| @end deftypevar |
| |
| @deftypevar int rl_filename_quoting_desired |
| Non-zero means that the results of the matches are to be quoted using |
| double quotes (or an application-specific quoting mechanism) if the |
| completed filename contains any characters in |
| @code{rl_filename_quote_chars}. This is @emph{always} non-zero |
| on entry, and can only be changed within a completion entry generator |
| function. The quoting is effected via a call to the function pointed to |
| by @code{rl_filename_quoting_function}. |
| @end deftypevar |
| |
| @deftypevar int rl_inhibit_completion |
| If this variable is non-zero, completion is inhibit<ed. The completion |
| character will be inserted as any other bound to @code{self-insert}. |
| @end deftypevar |
| |
| @deftypevar {Function *} rl_ignore_some_completions_function |
| This function, if defined, is called by the completer when real filename |
| completion is done, after all the matching names have been generated. |
| It is passed a @code{NULL} terminated array of matches. |
| The first element (@code{matches[0]}) is the |
| maximal substring common to all matches. This function can |
| re-arrange the list of matches as required, but each element deleted |
| from the array must be freed. |
| @end deftypevar |
| |
| @deftypevar {Function *} rl_directory_completion_hook |
| This function, if defined, is allowed to modify the directory portion |
| of filenames Readline completes. It is called with the address of a |
| string (the current directory name) as an argument. It could be used |
| to expand symbolic links or shell variables in pathnames. |
| @end deftypevar |
| |
| @deftypevar {VFunction *} rl_completion_display_matches_hook |
| If non-zero, then this is the address of a function to call when |
| completing a word would normally display the list of possible matches. |
| This function is called in lieu of Readline displaying the list. |
| It takes three arguments: |
| (@code{char **}@var{matches}, @code{int} @var{num_matches}, @code{int} @var{max_length}) |
| where @var{matches} is the array of matching strings, |
| @var{num_matches} is the number of strings in that array, and |
| @var{max_length} is the length of the longest string in that array. |
| Readline provides a convenience function, @code{rl_display_match_list}, |
| that takes care of doing the display to Readline's output stream. That |
| function may be called from this hook. |
| @end deftypevar |
| |
| @node A Short Completion Example |
| @subsection A Short Completion Example |
| |
| Here is a small application demonstrating the use of the GNU Readline |
| library. It is called @code{fileman}, and the source code resides in |
| @file{examples/fileman.c}. This sample application provides |
| completion of command names, line editing features, and access to the |
| history list. |
| |
| @page |
| @smallexample |
| /* fileman.c -- A tiny application which demonstrates how to use the |
| GNU Readline library. This application interactively allows users |
| to manipulate files and their modes. */ |
| |
| #include <stdio.h> |
| #include <sys/types.h> |
| #include <sys/file.h> |
| #include <sys/stat.h> |
| #include <sys/errno.h> |
| |
| #include <readline/readline.h> |
| #include <readline/history.h> |
| |
| extern char *getwd (); |
| extern char *xmalloc (); |
| |
| /* The names of functions that actually do the manipulation. */ |
| int com_list (), com_view (), com_rename (), com_stat (), com_pwd (); |
| int com_delete (), com_help (), com_cd (), com_quit (); |
| |
| /* A structure which contains information on the commands this program |
| can understand. */ |
| |
| typedef struct @{ |
| char *name; /* User printable name of the function. */ |
| Function *func; /* Function to call to do the job. */ |
| char *doc; /* Documentation for this function. */ |
| @} COMMAND; |
| |
| COMMAND commands[] = @{ |
| @{ "cd", com_cd, "Change to directory DIR" @}, |
| @{ "delete", com_delete, "Delete FILE" @}, |
| @{ "help", com_help, "Display this text" @}, |
| @{ "?", com_help, "Synonym for `help'" @}, |
| @{ "list", com_list, "List files in DIR" @}, |
| @{ "ls", com_list, "Synonym for `list'" @}, |
| @{ "pwd", com_pwd, "Print the current working directory" @}, |
| @{ "quit", com_quit, "Quit using Fileman" @}, |
| @{ "rename", com_rename, "Rename FILE to NEWNAME" @}, |
| @{ "stat", com_stat, "Print out statistics on FILE" @}, |
| @{ "view", com_view, "View the contents of FILE" @}, |
| @{ (char *)NULL, (Function *)NULL, (char *)NULL @} |
| @}; |
| |
| /* Forward declarations. */ |
| char *stripwhite (); |
| COMMAND *find_command (); |
| |
| /* The name of this program, as taken from argv[0]. */ |
| char *progname; |
| |
| /* When non-zero, this global means the user is done using this program. */ |
| int done; |
| |
| char * |
| dupstr (s) |
| int s; |
| @{ |
| char *r; |
| |
| r = xmalloc (strlen (s) + 1); |
| strcpy (r, s); |
| return (r); |
| @} |
| |
| main (argc, argv) |
| int argc; |
| char **argv; |
| @{ |
| char *line, *s; |
| |
| progname = argv[0]; |
| |
| initialize_readline (); /* Bind our completer. */ |
| |
| /* Loop reading and executing lines until the user quits. */ |
| for ( ; done == 0; ) |
| @{ |
| line = readline ("FileMan: "); |
| |
| if (!line) |
| break; |
| |
| /* Remove leading and trailing whitespace from the line. |
| Then, if there is anything left, add it to the history list |
| and execute it. */ |
| s = stripwhite (line); |
| |
| if (*s) |
| @{ |
| add_history (s); |
| execute_line (s); |
| @} |
| |
| free (line); |
| @} |
| exit (0); |
| @} |
| |
| /* Execute a command line. */ |
| int |
| execute_line (line) |
| char *line; |
| @{ |
| register int i; |
| COMMAND *command; |
| char *word; |
| |
| /* Isolate the command word. */ |
| i = 0; |
| while (line[i] && whitespace (line[i])) |
| i++; |
| word = line + i; |
| |
| while (line[i] && !whitespace (line[i])) |
| i++; |
| |
| if (line[i]) |
| line[i++] = '\0'; |
| |
| command = find_command (word); |
| |
| if (!command) |
| @{ |
| fprintf (stderr, "%s: No such command for FileMan.\n", word); |
| return (-1); |
| @} |
| |
| /* Get argument to command, if any. */ |
| while (whitespace (line[i])) |
| i++; |
| |
| word = line + i; |
| |
| /* Call the function. */ |
| return ((*(command->func)) (word)); |
| @} |
| |
| /* Look up NAME as the name of a command, and return a pointer to that |
| command. Return a NULL pointer if NAME isn't a command name. */ |
| COMMAND * |
| find_command (name) |
| char *name; |
| @{ |
| register int i; |
| |
| for (i = 0; commands[i].name; i++) |
| if (strcmp (name, commands[i].name) == 0) |
| return (&commands[i]); |
| |
| return ((COMMAND *)NULL); |
| @} |
| |
| /* Strip whitespace from the start and end of STRING. Return a pointer |
| into STRING. */ |
| char * |
| stripwhite (string) |
| char *string; |
| @{ |
| register char *s, *t; |
| |
| for (s = string; whitespace (*s); s++) |
| ; |
| |
| if (*s == 0) |
| return (s); |
| |
| t = s + strlen (s) - 1; |
| while (t > s && whitespace (*t)) |
| t--; |
| *++t = '\0'; |
| |
| return s; |
| @} |
| |
| /* **************************************************************** */ |
| /* */ |
| /* Interface to Readline Completion */ |
| /* */ |
| /* **************************************************************** */ |
| |
| char *command_generator (); |
| char **fileman_completion (); |
| |
| /* Tell the GNU Readline library how to complete. We want to try to complete |
| on command names if this is the first word in the line, or on filenames |
| if not. */ |
| initialize_readline () |
| @{ |
| /* Allow conditional parsing of the ~/.inputrc file. */ |
| rl_readline_name = "FileMan"; |
| |
| /* Tell the completer that we want a crack first. */ |
| rl_attempted_completion_function = (CPPFunction *)fileman_completion; |
| @} |
| |
| /* Attempt to complete on the contents of TEXT. START and END bound the |
| region of rl_line_buffer that contains the word to complete. TEXT is |
| the word to complete. We can use the entire contents of rl_line_buffer |
| in case we want to do some simple parsing. Return the array of matches, |
| or NULL if there aren't any. */ |
| char ** |
| fileman_completion (text, start, end) |
| char *text; |
| int start, end; |
| @{ |
| char **matches; |
| |
| matches = (char **)NULL; |
| |
| /* If this word is at the start of the line, then it is a command |
| to complete. Otherwise it is the name of a file in the current |
| directory. */ |
| if (start == 0) |
| matches = completion_matches (text, command_generator); |
| |
| return (matches); |
| @} |
| |
| /* Generator function for command completion. STATE lets us know whether |
| to start from scratch; without any state (i.e. STATE == 0), then we |
| start at the top of the list. */ |
| char * |
| command_generator (text, state) |
| char *text; |
| int state; |
| @{ |
| static int list_index, len; |
| char *name; |
| |
| /* If this is a new word to complete, initialize now. This includes |
| saving the length of TEXT for efficiency, and initializing the index |
| variable to 0. */ |
| if (!state) |
| @{ |
| list_index = 0; |
| len = strlen (text); |
| @} |
| |
| /* Return the next name which partially matches from the command list. */ |
| while (name = commands[list_index].name) |
| @{ |
| list_index++; |
| |
| if (strncmp (name, text, len) == 0) |
| return (dupstr(name)); |
| @} |
| |
| /* If no names matched, then return NULL. */ |
| return ((char *)NULL); |
| @} |
| |
| /* **************************************************************** */ |
| /* */ |
| /* FileMan Commands */ |
| /* */ |
| /* **************************************************************** */ |
| |
| /* String to pass to system (). This is for the LIST, VIEW and RENAME |
| commands. */ |
| static char syscom[1024]; |
| |
| /* List the file(s) named in arg. */ |
| com_list (arg) |
| char *arg; |
| @{ |
| if (!arg) |
| arg = ""; |
| |
| sprintf (syscom, "ls -FClg %s", arg); |
| return (system (syscom)); |
| @} |
| |
| com_view (arg) |
| char *arg; |
| @{ |
| if (!valid_argument ("view", arg)) |
| return 1; |
| |
| sprintf (syscom, "more %s", arg); |
| return (system (syscom)); |
| @} |
| |
| com_rename (arg) |
| char *arg; |
| @{ |
| too_dangerous ("rename"); |
| return (1); |
| @} |
| |
| com_stat (arg) |
| char *arg; |
| @{ |
| struct stat finfo; |
| |
| if (!valid_argument ("stat", arg)) |
| return (1); |
| |
| if (stat (arg, &finfo) == -1) |
| @{ |
| perror (arg); |
| return (1); |
| @} |
| |
| printf ("Statistics for `%s':\n", arg); |
| |
| printf ("%s has %d link%s, and is %d byte%s in length.\n", arg, |
| finfo.st_nlink, |
| (finfo.st_nlink == 1) ? "" : "s", |
| finfo.st_size, |
| (finfo.st_size == 1) ? "" : "s"); |
| printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime)); |
| printf (" Last access at: %s", ctime (&finfo.st_atime)); |
| printf (" Last modified at: %s", ctime (&finfo.st_mtime)); |
| return (0); |
| @} |
| |
| com_delete (arg) |
| char *arg; |
| @{ |
| too_dangerous ("delete"); |
| return (1); |
| @} |
| |
| /* Print out help for ARG, or for all of the commands if ARG is |
| not present. */ |
| com_help (arg) |
| char *arg; |
| @{ |
| register int i; |
| int printed = 0; |
| |
| for (i = 0; commands[i].name; i++) |
| @{ |
| if (!*arg || (strcmp (arg, commands[i].name) == 0)) |
| @{ |
| printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc); |
| printed++; |
| @} |
| @} |
| |
| if (!printed) |
| @{ |
| printf ("No commands match `%s'. Possibilties are:\n", arg); |
| |
| for (i = 0; commands[i].name; i++) |
| @{ |
| /* Print in six columns. */ |
| if (printed == 6) |
| @{ |
| printed = 0; |
| printf ("\n"); |
| @} |
| |
| printf ("%s\t", commands[i].name); |
| printed++; |
| @} |
| |
| if (printed) |
| printf ("\n"); |
| @} |
| return (0); |
| @} |
| |
| /* Change to the directory ARG. */ |
| com_cd (arg) |
| char *arg; |
| @{ |
| if (chdir (arg) == -1) |
| @{ |
| perror (arg); |
| return 1; |
| @} |
| |
| com_pwd (""); |
| return (0); |
| @} |
| |
| /* Print out the current working directory. */ |
| com_pwd (ignore) |
| char *ignore; |
| @{ |
| char dir[1024], *s; |
| |
| s = getwd (dir); |
| if (s == 0) |
| @{ |
| printf ("Error getting pwd: %s\n", dir); |
| return 1; |
| @} |
| |
| printf ("Current directory is %s\n", dir); |
| return 0; |
| @} |
| |
| /* The user wishes to quit using this program. Just set DONE non-zero. */ |
| com_quit (arg) |
| char *arg; |
| @{ |
| done = 1; |
| return (0); |
| @} |
| |
| /* Function which tells you that you can't do this. */ |
| too_dangerous (caller) |
| char *caller; |
| @{ |
| fprintf (stderr, |
| "%s: Too dangerous for me to distribute. Write it yourself.\n", |
| caller); |
| @} |
| |
| /* Return non-zero if ARG is a valid argument for CALLER, else print |
| an error message and return zero. */ |
| int |
| valid_argument (caller, arg) |
| char *caller, *arg; |
| @{ |
| if (!arg || !*arg) |
| @{ |
| fprintf (stderr, "%s: Argument required.\n", caller); |
| return (0); |
| @} |
| |
| return (1); |
| @} |
| @end smallexample |