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4:
5: @ifinfo
6: This document describes the GNU Readline Library, a utility for aiding
7: in the consistency of user interface across discrete programs that need
8: to provide a command line interface.
9:
10: Copyright (C) 1988--2014 Free Software Foundation, Inc.
11:
12: Permission is granted to make and distribute verbatim copies of
13: this manual provided the copyright notice and this permission notice
14: pare preserved on all copies.
15:
16: @ignore
17: Permission is granted to process this file through TeX and print the
18: results, provided the printed document carries copying permission
19: notice identical to this one except for the removal of this paragraph
20: (this paragraph not being relevant to the printed manual).
21: @end ignore
22:
23: Permission is granted to copy and distribute modified versions of this
24: manual under the conditions for verbatim copying, provided that the entire
25: resulting derived work is distributed under the terms of a permission
26: notice identical to this one.
27:
28: Permission is granted to copy and distribute translations of this manual
29: into another language, under the above conditions for modified versions,
30: except that this permission notice may be stated in a translation approved
31: by the Foundation.
32: @end ifinfo
33:
34: @node Programming with GNU Readline
35: @chapter Programming with GNU Readline
36:
37: This chapter describes the interface between the @sc{gnu} Readline Library and
38: other programs. If you are a programmer, and you wish to include the
39: features found in @sc{gnu} Readline
40: such as completion, line editing, and interactive history manipulation
41: in your own programs, this section is for you.
42:
43: @menu
44: * Basic Behavior:: Using the default behavior of Readline.
45: * Custom Functions:: Adding your own functions to Readline.
46: * Readline Variables:: Variables accessible to custom
47: functions.
48: * Readline Convenience Functions:: Functions which Readline supplies to
49: aid in writing your own custom
50: functions.
51: * Readline Signal Handling:: How Readline behaves when it receives signals.
52: * Custom Completers:: Supplanting or supplementing Readline's
53: completion functions.
54: @end menu
55:
56: @node Basic Behavior
57: @section Basic Behavior
58:
59: Many programs provide a command line interface, such as @code{mail},
60: @code{ftp}, and @code{sh}. For such programs, the default behaviour of
61: Readline is sufficient. This section describes how to use Readline in
62: the simplest way possible, perhaps to replace calls in your code to
63: @code{gets()} or @code{fgets()}.
64:
65: @findex readline
66: @cindex readline, function
67:
68: The function @code{readline()} prints a prompt @var{prompt}
69: and then reads and returns a single line of text from the user.
70: If @var{prompt} is @code{NULL} or the empty string, no prompt is displayed.
71: The line @code{readline} returns is allocated with @code{malloc()};
72: the caller should @code{free()} the line when it has finished with it.
73: The declaration for @code{readline} in ANSI C is
74:
75: @example
76: @code{char *readline (const char *@var{prompt});}
77: @end example
78:
79: @noindent
80: So, one might say
81: @example
82: @code{char *line = readline ("Enter a line: ");}
83: @end example
84: @noindent
85: in order to read a line of text from the user.
86: The line returned has the final newline removed, so only the
87: text remains.
88:
89: If @code{readline} encounters an @code{EOF} while reading the line, and the
90: line is empty at that point, then @code{(char *)NULL} is returned.
91: Otherwise, the line is ended just as if a newline had been typed.
92:
93: If you want the user to be able to get at the line later, (with
94: @key{C-p} for example), you must call @code{add_history()} to save the
95: line away in a @dfn{history} list of such lines.
96:
97: @example
98: @code{add_history (line)};
99: @end example
100:
101: @noindent
102: For full details on the GNU History Library, see the associated manual.
103:
104: It is preferable to avoid saving empty lines on the history list, since
105: users rarely have a burning need to reuse a blank line. Here is
106: a function which usefully replaces the standard @code{gets()} library
107: function, and has the advantage of no static buffer to overflow:
108:
109: @example
110: /* A static variable for holding the line. */
111: static char *line_read = (char *)NULL;
112:
113: /* Read a string, and return a pointer to it.
114: Returns NULL on EOF. */
115: char *
116: rl_gets ()
117: @{
118: /* If the buffer has already been allocated,
119: return the memory to the free pool. */
120: if (line_read)
121: @{
122: free (line_read);
123: line_read = (char *)NULL;
124: @}
125:
126: /* Get a line from the user. */
127: line_read = readline ("");
128:
129: /* If the line has any text in it,
130: save it on the history. */
131: if (line_read && *line_read)
132: add_history (line_read);
133:
134: return (line_read);
135: @}
136: @end example
137:
138: This function gives the user the default behaviour of @key{TAB}
139: completion: completion on file names. If you do not want Readline to
140: complete on filenames, you can change the binding of the @key{TAB} key
141: with @code{rl_bind_key()}.
142:
143: @example
144: @code{int rl_bind_key (int @var{key}, rl_command_func_t *@var{function});}
145: @end example
146:
147: @code{rl_bind_key()} takes two arguments: @var{key} is the character that
148: you want to bind, and @var{function} is the address of the function to
149: call when @var{key} is pressed. Binding @key{TAB} to @code{rl_insert()}
150: makes @key{TAB} insert itself.
151: @code{rl_bind_key()} returns non-zero if @var{key} is not a valid
152: ASCII character code (between 0 and 255).
153:
154: Thus, to disable the default @key{TAB} behavior, the following suffices:
155: @example
156: @code{rl_bind_key ('\t', rl_insert);}
157: @end example
158:
159: This code should be executed once at the start of your program; you
160: might write a function called @code{initialize_readline()} which
161: performs this and other desired initializations, such as installing
162: custom completers (@pxref{Custom Completers}).
163:
164: @node Custom Functions
165: @section Custom Functions
166:
167: Readline provides many functions for manipulating the text of
168: the line, but it isn't possible to anticipate the needs of all
169: programs. This section describes the various functions and variables
170: defined within the Readline library which allow a user program to add
171: customized functionality to Readline.
172:
173: Before declaring any functions that customize Readline's behavior, or
174: using any functionality Readline provides in other code, an
175: application writer should include the file @code{<readline/readline.h>}
176: in any file that uses Readline's features. Since some of the definitions
177: in @code{readline.h} use the @code{stdio} library, the file
178: @code{<stdio.h>} should be included before @code{readline.h}.
179:
180: @code{readline.h} defines a C preprocessor variable that should
181: be treated as an integer, @code{RL_READLINE_VERSION}, which may
182: be used to conditionally compile application code depending on
183: the installed Readline version. The value is a hexadecimal
184: encoding of the major and minor version numbers of the library,
185: of the form 0x@var{MMmm}. @var{MM} is the two-digit major
186: version number; @var{mm} is the two-digit minor version number.
187: For Readline 4.2, for example, the value of
188: @code{RL_READLINE_VERSION} would be @code{0x0402}.
189:
190: @menu
191: * Readline Typedefs:: C declarations to make code readable.
192: * Function Writing:: Variables and calling conventions.
193: @end menu
194:
195: @node Readline Typedefs
196: @subsection Readline Typedefs
197:
198: For readability, we declare a number of new object types, all pointers
199: to functions.
200:
201: The reason for declaring these new types is to make it easier to write
202: code describing pointers to C functions with appropriately prototyped
203: arguments and return values.
204:
205: For instance, say we want to declare a variable @var{func} as a pointer
206: to a function which takes two @code{int} arguments and returns an
207: @code{int} (this is the type of all of the Readline bindable functions).
208: Instead of the classic C declaration
209:
210: @code{int (*func)();}
211:
212: @noindent
213: or the ANSI-C style declaration
214:
215: @code{int (*func)(int, int);}
216:
217: @noindent
218: we may write
219:
220: @code{rl_command_func_t *func;}
221:
222: The full list of function pointer types available is
223:
224: @table @code
225: @item typedef int rl_command_func_t (int, int);
226:
227: @item typedef char *rl_compentry_func_t (const char *, int);
228:
229: @item typedef char **rl_completion_func_t (const char *, int, int);
230:
231: @item typedef char *rl_quote_func_t (char *, int, char *);
232:
233: @item typedef char *rl_dequote_func_t (char *, int);
234:
235: @item typedef int rl_compignore_func_t (char **);
236:
237: @item typedef void rl_compdisp_func_t (char **, int, int);
238:
239: @item typedef int rl_hook_func_t (void);
240:
241: @item typedef int rl_getc_func_t (FILE *);
242:
243: @item typedef int rl_linebuf_func_t (char *, int);
244:
245: @item typedef int rl_intfunc_t (int);
246: @item #define rl_ivoidfunc_t rl_hook_func_t
247: @item typedef int rl_icpfunc_t (char *);
248: @item typedef int rl_icppfunc_t (char **);
249:
250: @item typedef void rl_voidfunc_t (void);
251: @item typedef void rl_vintfunc_t (int);
252: @item typedef void rl_vcpfunc_t (char *);
253: @item typedef void rl_vcppfunc_t (char **);
254:
255: @end table
256:
257: @node Function Writing
258: @subsection Writing a New Function
259:
260: In order to write new functions for Readline, you need to know the
261: calling conventions for keyboard-invoked functions, and the names of the
262: variables that describe the current state of the line read so far.
263:
264: The calling sequence for a command @code{foo} looks like
265:
266: @example
267: @code{int foo (int count, int key)}
268: @end example
269:
270: @noindent
271: where @var{count} is the numeric argument (or 1 if defaulted) and
272: @var{key} is the key that invoked this function.
273:
274: It is completely up to the function as to what should be done with the
275: numeric argument. Some functions use it as a repeat count, some
276: as a flag, and others to choose alternate behavior (refreshing the current
277: line as opposed to refreshing the screen, for example). Some choose to
278: ignore it. In general, if a
279: function uses the numeric argument as a repeat count, it should be able
280: to do something useful with both negative and positive arguments.
281: At the very least, it should be aware that it can be passed a
282: negative argument.
283:
284: A command function should return 0 if its action completes successfully,
285: and a non-zero value if some error occurs.
286: This is the convention obeyed by all of the builtin Readline bindable
287: command functions.
288:
289: @node Readline Variables
290: @section Readline Variables
291:
292: These variables are available to function writers.
293:
294: @deftypevar {char *} rl_line_buffer
295: This is the line gathered so far. You are welcome to modify the
296: contents of the line, but see @ref{Allowing Undoing}. The
297: function @code{rl_extend_line_buffer} is available to increase
298: the memory allocated to @code{rl_line_buffer}.
299: @end deftypevar
300:
301: @deftypevar int rl_point
302: The offset of the current cursor position in @code{rl_line_buffer}
303: (the @emph{point}).
304: @end deftypevar
305:
306: @deftypevar int rl_end
307: The number of characters present in @code{rl_line_buffer}. When
308: @code{rl_point} is at the end of the line, @code{rl_point} and
309: @code{rl_end} are equal.
310: @end deftypevar
311:
312: @deftypevar int rl_mark
313: The @var{mark} (saved position) in the current line. If set, the mark
314: and point define a @emph{region}.
315: @end deftypevar
316:
317: @deftypevar int rl_done
318: Setting this to a non-zero value causes Readline to return the current
319: line immediately.
320: @end deftypevar
321:
322: @deftypevar int rl_num_chars_to_read
323: Setting this to a positive value before calling @code{readline()} causes
324: Readline to return after accepting that many characters, rather
325: than reading up to a character bound to @code{accept-line}.
326: @end deftypevar
327:
328: @deftypevar int rl_pending_input
329: Setting this to a value makes it the next keystroke read. This is a
330: way to stuff a single character into the input stream.
331: @end deftypevar
332:
333: @deftypevar int rl_dispatching
334: Set to a non-zero value if a function is being called from a key binding;
335: zero otherwise. Application functions can test this to discover whether
336: they were called directly or by Readline's dispatching mechanism.
337: @end deftypevar
338:
339: @deftypevar int rl_erase_empty_line
340: Setting this to a non-zero value causes Readline to completely erase
341: the current line, including any prompt, any time a newline is typed as
342: the only character on an otherwise-empty line. The cursor is moved to
343: the beginning of the newly-blank line.
344: @end deftypevar
345:
346: @deftypevar {char *} rl_prompt
347: The prompt Readline uses. This is set from the argument to
348: @code{readline()}, and should not be assigned to directly.
349: The @code{rl_set_prompt()} function (@pxref{Redisplay}) may
350: be used to modify the prompt string after calling @code{readline()}.
351: @end deftypevar
352:
353: @deftypevar {char *} rl_display_prompt
354: The string displayed as the prompt. This is usually identical to
355: @var{rl_prompt}, but may be changed temporarily by functions that
356: use the prompt string as a message area, such as incremental search.
357: @end deftypevar
358:
359: @deftypevar int rl_already_prompted
360: If an application wishes to display the prompt itself, rather than have
361: Readline do it the first time @code{readline()} is called, it should set
362: this variable to a non-zero value after displaying the prompt.
363: The prompt must also be passed as the argument to @code{readline()} so
364: the redisplay functions can update the display properly.
365: The calling application is responsible for managing the value; Readline
366: never sets it.
367: @end deftypevar
368:
369: @deftypevar {const char *} rl_library_version
370: The version number of this revision of the library.
371: @end deftypevar
372:
373: @deftypevar int rl_readline_version
374: An integer encoding the current version of the library. The encoding is
375: of the form 0x@var{MMmm}, where @var{MM} is the two-digit major version
376: number, and @var{mm} is the two-digit minor version number.
377: For example, for Readline-4.2, @code{rl_readline_version} would have the
378: value 0x0402.
379: @end deftypevar
380:
381: @deftypevar {int} rl_gnu_readline_p
382: Always set to 1, denoting that this is @sc{gnu} readline rather than some
383: emulation.
384: @end deftypevar
385:
386: @deftypevar {const char *} rl_terminal_name
387: The terminal type, used for initialization. If not set by the application,
388: Readline sets this to the value of the @env{TERM} environment variable
389: the first time it is called.
390: @end deftypevar
391:
392: @deftypevar {const char *} rl_readline_name
393: This variable is set to a unique name by each application using Readline.
394: The value allows conditional parsing of the inputrc file
395: (@pxref{Conditional Init Constructs}).
396: @end deftypevar
397:
398: @deftypevar {FILE *} rl_instream
399: The stdio stream from which Readline reads input.
400: If @code{NULL}, Readline defaults to @var{stdin}.
401: @end deftypevar
402:
403: @deftypevar {FILE *} rl_outstream
404: The stdio stream to which Readline performs output.
405: If @code{NULL}, Readline defaults to @var{stdout}.
406: @end deftypevar
407:
408: @deftypevar int rl_prefer_env_winsize
409: If non-zero, Readline gives values found in the @env{LINES} and
410: @env{COLUMNS} environment variables greater precedence than values fetched
411: from the kernel when computing the screen dimensions.
412: @end deftypevar
413:
414: @deftypevar {rl_command_func_t *} rl_last_func
415: The address of the last command function Readline executed. May be used to
416: test whether or not a function is being executed twice in succession, for
417: example.
418: @end deftypevar
419:
420: @deftypevar {rl_hook_func_t *} rl_startup_hook
421: If non-zero, this is the address of a function to call just
422: before @code{readline} prints the first prompt.
423: @end deftypevar
424:
425: @deftypevar {rl_hook_func_t *} rl_pre_input_hook
426: If non-zero, this is the address of a function to call after
427: the first prompt has been printed and just before @code{readline}
428: starts reading input characters.
429: @end deftypevar
430:
431: @deftypevar {rl_hook_func_t *} rl_event_hook
432: If non-zero, this is the address of a function to call periodically
433: when Readline is waiting for terminal input.
434: By default, this will be called at most ten times a second if there
435: is no keyboard input.
436: @end deftypevar
437:
438: @deftypevar {rl_getc_func_t *} rl_getc_function
439: If non-zero, Readline will call indirectly through this pointer
440: to get a character from the input stream. By default, it is set to
441: @code{rl_getc}, the default Readline character input function
442: (@pxref{Character Input}).
443: In general, an application that sets @var{rl_getc_function} should consider
444: setting @var{rl_input_available_hook} as well.
445: @end deftypevar
446:
447: @deftypevar {rl_hook_func_t *} rl_signal_event_hook
448: If non-zero, this is the address of a function to call if a read system
449: call is interrupted when Readline is reading terminal input.
450: @end deftypevar
451:
452: @deftypevar {rl_hook_func_t *} rl_input_available_hook
453: If non-zero, Readline will use this function's return value when it needs
454: to determine whether or not there is available input on the current input
455: source.
456: The default hook checks @code{rl_instream}; if an application is using a
457: different input source, it should set the hook appropriately.
458: Readline queries for available input when implementing intra-key-sequence
459: timeouts during input and incremental searches.
460: This may use an application-specific timeout before returning a value;
461: Readline uses the value passed to @code{rl_set_keyboard_input_timeout()}
462: or the value of the user-settable @var{keyseq-timeout} variable.
463: This is designed for use by applications using Readline's callback interface
464: (@pxref{Alternate Interface}), which may not use the traditional
465: @code{read(2)} and file descriptor interface, or other applications using
466: a different input mechanism.
467: If an application uses an input mechanism or hook that can potentially exceed
468: the value of @var{keyseq-timeout}, it should increase the timeout or set
469: this hook appropriately even when not using the callback interface.
470: In general, an application that sets @var{rl_getc_function} should consider
471: setting @var{rl_input_available_hook} as well.
472: @end deftypevar
473:
474: @deftypevar {rl_voidfunc_t *} rl_redisplay_function
475: If non-zero, Readline will call indirectly through this pointer
476: to update the display with the current contents of the editing buffer.
477: By default, it is set to @code{rl_redisplay}, the default Readline
478: redisplay function (@pxref{Redisplay}).
479: @end deftypevar
480:
481: @deftypevar {rl_vintfunc_t *} rl_prep_term_function
482: If non-zero, Readline will call indirectly through this pointer
483: to initialize the terminal. The function takes a single argument, an
484: @code{int} flag that says whether or not to use eight-bit characters.
485: By default, this is set to @code{rl_prep_terminal}
486: (@pxref{Terminal Management}).
487: @end deftypevar
488:
489: @deftypevar {rl_voidfunc_t *} rl_deprep_term_function
490: If non-zero, Readline will call indirectly through this pointer
491: to reset the terminal. This function should undo the effects of
492: @code{rl_prep_term_function}.
493: By default, this is set to @code{rl_deprep_terminal}
494: (@pxref{Terminal Management}).
495: @end deftypevar
496:
497: @deftypevar {Keymap} rl_executing_keymap
498: This variable is set to the keymap (@pxref{Keymaps}) in which the
499: currently executing readline function was found.
500: @end deftypevar
501:
502: @deftypevar {Keymap} rl_binding_keymap
503: This variable is set to the keymap (@pxref{Keymaps}) in which the
504: last key binding occurred.
505: @end deftypevar
506:
507: @deftypevar {char *} rl_executing_macro
508: This variable is set to the text of any currently-executing macro.
509: @end deftypevar
510:
511: @deftypevar int rl_executing_key
512: The key that caused the dispatch to the currently-executing Readline function.
513: @end deftypevar
514:
515: @deftypevar {char *} rl_executing_keyseq
516: The full key sequence that caused the dispatch to the currently-executing
517: Readline function.
518: @end deftypevar
519:
520: @deftypevar int rl_key_sequence_length
521: The number of characters in @var{rl_executing_keyseq}.
522: @end deftypevar
523:
524: @deftypevar {int} rl_readline_state
525: A variable with bit values that encapsulate the current Readline state.
526: A bit is set with the @code{RL_SETSTATE} macro, and unset with the
527: @code{RL_UNSETSTATE} macro. Use the @code{RL_ISSTATE} macro to test
528: whether a particular state bit is set. Current state bits include:
529:
530: @table @code
531: @item RL_STATE_NONE
532: Readline has not yet been called, nor has it begun to initialize.
533: @item RL_STATE_INITIALIZING
534: Readline is initializing its internal data structures.
535: @item RL_STATE_INITIALIZED
536: Readline has completed its initialization.
537: @item RL_STATE_TERMPREPPED
538: Readline has modified the terminal modes to do its own input and redisplay.
539: @item RL_STATE_READCMD
540: Readline is reading a command from the keyboard.
541: @item RL_STATE_METANEXT
542: Readline is reading more input after reading the meta-prefix character.
543: @item RL_STATE_DISPATCHING
544: Readline is dispatching to a command.
545: @item RL_STATE_MOREINPUT
546: Readline is reading more input while executing an editing command.
547: @item RL_STATE_ISEARCH
548: Readline is performing an incremental history search.
549: @item RL_STATE_NSEARCH
550: Readline is performing a non-incremental history search.
551: @item RL_STATE_SEARCH
552: Readline is searching backward or forward through the history for a string.
553: @item RL_STATE_NUMERICARG
554: Readline is reading a numeric argument.
555: @item RL_STATE_MACROINPUT
556: Readline is currently getting its input from a previously-defined keyboard
557: macro.
558: @item RL_STATE_MACRODEF
559: Readline is currently reading characters defining a keyboard macro.
560: @item RL_STATE_OVERWRITE
561: Readline is in overwrite mode.
562: @item RL_STATE_COMPLETING
563: Readline is performing word completion.
564: @item RL_STATE_SIGHANDLER
565: Readline is currently executing the readline signal handler.
566: @item RL_STATE_UNDOING
567: Readline is performing an undo.
568: @item RL_STATE_INPUTPENDING
569: Readline has input pending due to a call to @code{rl_execute_next()}.
570: @item RL_STATE_TTYCSAVED
571: Readline has saved the values of the terminal's special characters.
572: @item RL_STATE_CALLBACK
573: Readline is currently using the alternate (callback) interface
574: (@pxref{Alternate Interface}).
575: @item RL_STATE_VIMOTION
576: Readline is reading the argument to a vi-mode "motion" command.
577: @item RL_STATE_MULTIKEY
578: Readline is reading a multiple-keystroke command.
579: @item RL_STATE_VICMDONCE
580: Readline has entered vi command (movement) mode at least one time during
581: the current call to @code{readline()}.
582: @item RL_STATE_DONE
583: Readline has read a key sequence bound to @code{accept-line}
584: and is about to return the line to the caller.
585: @end table
586:
587: @end deftypevar
588:
589: @deftypevar {int} rl_explicit_arg
590: Set to a non-zero value if an explicit numeric argument was specified by
591: the user. Only valid in a bindable command function.
592: @end deftypevar
593:
594: @deftypevar {int} rl_numeric_arg
595: Set to the value of any numeric argument explicitly specified by the user
596: before executing the current Readline function. Only valid in a bindable
597: command function.
598: @end deftypevar
599:
600: @deftypevar {int} rl_editing_mode
601: Set to a value denoting Readline's current editing mode. A value of
602: @var{1} means Readline is currently in emacs mode; @var{0}
603: means that vi mode is active.
604: @end deftypevar
605:
606:
607: @node Readline Convenience Functions
608: @section Readline Convenience Functions
609:
610: @menu
611: * Function Naming:: How to give a function you write a name.
612: * Keymaps:: Making keymaps.
613: * Binding Keys:: Changing Keymaps.
614: * Associating Function Names and Bindings:: Translate function names to
615: key sequences.
616: * Allowing Undoing:: How to make your functions undoable.
617: * Redisplay:: Functions to control line display.
618: * Modifying Text:: Functions to modify @code{rl_line_buffer}.
619: * Character Input:: Functions to read keyboard input.
620: * Terminal Management:: Functions to manage terminal settings.
621: * Utility Functions:: Generally useful functions and hooks.
622: * Miscellaneous Functions:: Functions that don't fall into any category.
623: * Alternate Interface:: Using Readline in a `callback' fashion.
624: * A Readline Example:: An example Readline function.
625: * Alternate Interface Example:: An example program using the alternate interface.
626: @end menu
627:
628: @node Function Naming
629: @subsection Naming a Function
630:
631: The user can dynamically change the bindings of keys while using
632: Readline. This is done by representing the function with a descriptive
633: name. The user is able to type the descriptive name when referring to
634: the function. Thus, in an init file, one might find
635:
636: @example
637: Meta-Rubout: backward-kill-word
638: @end example
639:
640: This binds the keystroke @key{Meta-Rubout} to the function
641: @emph{descriptively} named @code{backward-kill-word}. You, as the
642: programmer, should bind the functions you write to descriptive names as
643: well. Readline provides a function for doing that:
644:
645: @deftypefun int rl_add_defun (const char *name, rl_command_func_t *function, int key)
646: Add @var{name} to the list of named functions. Make @var{function} be
647: the function that gets called. If @var{key} is not -1, then bind it to
648: @var{function} using @code{rl_bind_key()}.
649: @end deftypefun
650:
651: Using this function alone is sufficient for most applications.
652: It is the recommended way to add a few functions to the default
653: functions that Readline has built in.
654: If you need to do something other than adding a function to Readline,
655: you may need to use the underlying functions described below.
656:
657: @node Keymaps
658: @subsection Selecting a Keymap
659:
660: Key bindings take place on a @dfn{keymap}. The keymap is the
661: association between the keys that the user types and the functions that
662: get run. You can make your own keymaps, copy existing keymaps, and tell
663: Readline which keymap to use.
664:
665: @deftypefun Keymap rl_make_bare_keymap (void)
666: Returns a new, empty keymap. The space for the keymap is allocated with
667: @code{malloc()}; the caller should free it by calling
668: @code{rl_free_keymap()} when done.
669: @end deftypefun
670:
671: @deftypefun Keymap rl_copy_keymap (Keymap map)
672: Return a new keymap which is a copy of @var{map}.
673: @end deftypefun
674:
675: @deftypefun Keymap rl_make_keymap (void)
676: Return a new keymap with the printing characters bound to rl_insert,
677: the lowercase Meta characters bound to run their equivalents, and
678: the Meta digits bound to produce numeric arguments.
679: @end deftypefun
680:
681: @deftypefun void rl_discard_keymap (Keymap keymap)
682: Free the storage associated with the data in @var{keymap}.
683: The caller should free @var{keymap}.
684: @end deftypefun
685:
686: @deftypefun void rl_free_keymap (Keymap keymap)
687: Free all storage associated with @var{keymap}. This calls
688: @code{rl_discard_keymap} to free subordindate keymaps and macros.
689: @end deftypefun
690:
691: Readline has several internal keymaps. These functions allow you to
692: change which keymap is active.
693:
694: @deftypefun Keymap rl_get_keymap (void)
695: Returns the currently active keymap.
696: @end deftypefun
697:
698: @deftypefun void rl_set_keymap (Keymap keymap)
699: Makes @var{keymap} the currently active keymap.
700: @end deftypefun
701:
702: @deftypefun Keymap rl_get_keymap_by_name (const char *name)
703: Return the keymap matching @var{name}. @var{name} is one which would
704: be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
705: @end deftypefun
706:
707: @deftypefun {char *} rl_get_keymap_name (Keymap keymap)
708: Return the name matching @var{keymap}. @var{name} is one which would
709: be supplied in a @code{set keymap} inputrc line (@pxref{Readline Init File}).
710: @end deftypefun
711:
712: @node Binding Keys
713: @subsection Binding Keys
714:
715: Key sequences are associate with functions through the keymap.
716: Readline has several internal keymaps: @code{emacs_standard_keymap},
717: @code{emacs_meta_keymap}, @code{emacs_ctlx_keymap},
718: @code{vi_movement_keymap}, and @code{vi_insertion_keymap}.
719: @code{emacs_standard_keymap} is the default, and the examples in
720: this manual assume that.
721:
722: Since @code{readline()} installs a set of default key bindings the first
723: time it is called, there is always the danger that a custom binding
724: installed before the first call to @code{readline()} will be overridden.
725: An alternate mechanism is to install custom key bindings in an
726: initialization function assigned to the @code{rl_startup_hook} variable
727: (@pxref{Readline Variables}).
728:
729: These functions manage key bindings.
730:
731: @deftypefun int rl_bind_key (int key, rl_command_func_t *function)
732: Binds @var{key} to @var{function} in the currently active keymap.
733: Returns non-zero in the case of an invalid @var{key}.
734: @end deftypefun
735:
736: @deftypefun int rl_bind_key_in_map (int key, rl_command_func_t *function, Keymap map)
737: Bind @var{key} to @var{function} in @var{map}.
738: Returns non-zero in the case of an invalid @var{key}.
739: @end deftypefun
740:
741: @deftypefun int rl_bind_key_if_unbound (int key, rl_command_func_t *function)
742: Binds @var{key} to @var{function} if it is not already bound in the
743: currently active keymap.
744: Returns non-zero in the case of an invalid @var{key} or if @var{key} is
745: already bound.
746: @end deftypefun
747:
748: @deftypefun int rl_bind_key_if_unbound_in_map (int key, rl_command_func_t *function, Keymap map)
749: Binds @var{key} to @var{function} if it is not already bound in @var{map}.
750: Returns non-zero in the case of an invalid @var{key} or if @var{key} is
751: already bound.
752: @end deftypefun
753:
754: @deftypefun int rl_unbind_key (int key)
755: Bind @var{key} to the null function in the currently active keymap.
756: Returns non-zero in case of error.
757: @end deftypefun
758:
759: @deftypefun int rl_unbind_key_in_map (int key, Keymap map)
760: Bind @var{key} to the null function in @var{map}.
761: Returns non-zero in case of error.
762: @end deftypefun
763:
764: @deftypefun int rl_unbind_function_in_map (rl_command_func_t *function, Keymap map)
765: Unbind all keys that execute @var{function} in @var{map}.
766: @end deftypefun
767:
768: @deftypefun int rl_unbind_command_in_map (const char *command, Keymap map)
769: Unbind all keys that are bound to @var{command} in @var{map}.
770: @end deftypefun
771:
772: @deftypefun int rl_bind_keyseq (const char *keyseq, rl_command_func_t *function)
773: Bind the key sequence represented by the string @var{keyseq} to the function
774: @var{function}, beginning in the current keymap.
775: This makes new keymaps as necessary.
776: The return value is non-zero if @var{keyseq} is invalid.
777: @end deftypefun
778:
779: @deftypefun int rl_bind_keyseq_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
780: Bind the key sequence represented by the string @var{keyseq} to the function
781: @var{function}. This makes new keymaps as necessary.
782: Initial bindings are performed in @var{map}.
783: The return value is non-zero if @var{keyseq} is invalid.
784: @end deftypefun
785:
786: @deftypefun int rl_set_key (const char *keyseq, rl_command_func_t *function, Keymap map)
787: Equivalent to @code{rl_bind_keyseq_in_map}.
788: @end deftypefun
789:
790: @deftypefun int rl_bind_keyseq_if_unbound (const char *keyseq, rl_command_func_t *function)
791: Binds @var{keyseq} to @var{function} if it is not already bound in the
792: currently active keymap.
793: Returns non-zero in the case of an invalid @var{keyseq} or if @var{keyseq} is
794: already bound.
795: @end deftypefun
796:
797: @deftypefun int rl_bind_keyseq_if_unbound_in_map (const char *keyseq, rl_command_func_t *function, Keymap map)
798: Binds @var{keyseq} to @var{function} if it is not already bound in @var{map}.
799: Returns non-zero in the case of an invalid @var{keyseq} or if @var{keyseq} is
800: already bound.
801: @end deftypefun
802:
803: @deftypefun int rl_generic_bind (int type, const char *keyseq, char *data, Keymap map)
804: Bind the key sequence represented by the string @var{keyseq} to the arbitrary
805: pointer @var{data}. @var{type} says what kind of data is pointed to by
806: @var{data}; this can be a function (@code{ISFUNC}), a macro
807: (@code{ISMACR}), or a keymap (@code{ISKMAP}). This makes new keymaps as
808: necessary. The initial keymap in which to do bindings is @var{map}.
809: @end deftypefun
810:
811: @deftypefun int rl_parse_and_bind (char *line)
812: Parse @var{line} as if it had been read from the @code{inputrc} file and
813: perform any key bindings and variable assignments found
814: (@pxref{Readline Init File}).
815: @end deftypefun
816:
817: @deftypefun int rl_read_init_file (const char *filename)
818: Read keybindings and variable assignments from @var{filename}
819: (@pxref{Readline Init File}).
820: @end deftypefun
821:
822: @node Associating Function Names and Bindings
823: @subsection Associating Function Names and Bindings
824:
825: These functions allow you to find out what keys invoke named functions
826: and the functions invoked by a particular key sequence. You may also
827: associate a new function name with an arbitrary function.
828:
829: @deftypefun {rl_command_func_t *} rl_named_function (const char *name)
830: Return the function with name @var{name}.
831: @end deftypefun
832:
833: @deftypefun {rl_command_func_t *} rl_function_of_keyseq (const char *keyseq, Keymap map, int *type)
834: Return the function invoked by @var{keyseq} in keymap @var{map}.
835: If @var{map} is @code{NULL}, the current keymap is used. If @var{type} is
836: not @code{NULL}, the type of the object is returned in the @code{int} variable
837: it points to (one of @code{ISFUNC}, @code{ISKMAP}, or @code{ISMACR}).
838: @end deftypefun
839:
840: @deftypefun {char **} rl_invoking_keyseqs (rl_command_func_t *function)
841: Return an array of strings representing the key sequences used to
842: invoke @var{function} in the current keymap.
843: @end deftypefun
844:
845: @deftypefun {char **} rl_invoking_keyseqs_in_map (rl_command_func_t *function, Keymap map)
846: Return an array of strings representing the key sequences used to
847: invoke @var{function} in the keymap @var{map}.
848: @end deftypefun
849:
850: @deftypefun void rl_function_dumper (int readable)
851: Print the readline function names and the key sequences currently
852: bound to them to @code{rl_outstream}. If @var{readable} is non-zero,
853: the list is formatted in such a way that it can be made part of an
854: @code{inputrc} file and re-read.
855: @end deftypefun
856:
857: @deftypefun void rl_list_funmap_names (void)
858: Print the names of all bindable Readline functions to @code{rl_outstream}.
859: @end deftypefun
860:
861: @deftypefun {const char **} rl_funmap_names (void)
862: Return a NULL terminated array of known function names. The array is
863: sorted. The array itself is allocated, but not the strings inside. You
864: should free the array, but not the pointers, using @code{free} or
865: @code{rl_free} when you are done.
866: @end deftypefun
867:
868: @deftypefun int rl_add_funmap_entry (const char *name, rl_command_func_t *function)
869: Add @var{name} to the list of bindable Readline command names, and make
870: @var{function} the function to be called when @var{name} is invoked.
871: @end deftypefun
872:
873: @node Allowing Undoing
874: @subsection Allowing Undoing
875:
876: Supporting the undo command is a painless thing, and makes your
877: functions much more useful. It is certainly easy to try
878: something if you know you can undo it.
879:
880: If your function simply inserts text once, or deletes text once, and
881: uses @code{rl_insert_text()} or @code{rl_delete_text()} to do it, then
882: undoing is already done for you automatically.
883:
884: If you do multiple insertions or multiple deletions, or any combination
885: of these operations, you should group them together into one operation.
886: This is done with @code{rl_begin_undo_group()} and
887: @code{rl_end_undo_group()}.
888:
889: The types of events that can be undone are:
890:
891: @smallexample
892: enum undo_code @{ UNDO_DELETE, UNDO_INSERT, UNDO_BEGIN, UNDO_END @};
893: @end smallexample
894:
895: Notice that @code{UNDO_DELETE} means to insert some text, and
896: @code{UNDO_INSERT} means to delete some text. That is, the undo code
897: tells what to undo, not how to undo it. @code{UNDO_BEGIN} and
898: @code{UNDO_END} are tags added by @code{rl_begin_undo_group()} and
899: @code{rl_end_undo_group()}.
900:
901: @deftypefun int rl_begin_undo_group (void)
902: Begins saving undo information in a group construct. The undo
903: information usually comes from calls to @code{rl_insert_text()} and
904: @code{rl_delete_text()}, but could be the result of calls to
905: @code{rl_add_undo()}.
906: @end deftypefun
907:
908: @deftypefun int rl_end_undo_group (void)
909: Closes the current undo group started with @code{rl_begin_undo_group
910: ()}. There should be one call to @code{rl_end_undo_group()}
911: for each call to @code{rl_begin_undo_group()}.
912: @end deftypefun
913:
914: @deftypefun void rl_add_undo (enum undo_code what, int start, int end, char *text)
915: Remember how to undo an event (according to @var{what}). The affected
916: text runs from @var{start} to @var{end}, and encompasses @var{text}.
917: @end deftypefun
918:
919: @deftypefun void rl_free_undo_list (void)
920: Free the existing undo list.
921: @end deftypefun
922:
923: @deftypefun int rl_do_undo (void)
924: Undo the first thing on the undo list. Returns @code{0} if there was
925: nothing to undo, non-zero if something was undone.
926: @end deftypefun
927:
928: Finally, if you neither insert nor delete text, but directly modify the
929: existing text (e.g., change its case), call @code{rl_modifying()}
930: once, just before you modify the text. You must supply the indices of
931: the text range that you are going to modify.
932:
933: @deftypefun int rl_modifying (int start, int end)
934: Tell Readline to save the text between @var{start} and @var{end} as a
935: single undo unit. It is assumed that you will subsequently modify
936: that text.
937: @end deftypefun
938:
939: @node Redisplay
940: @subsection Redisplay
941:
942: @deftypefun void rl_redisplay (void)
943: Change what's displayed on the screen to reflect the current contents
944: of @code{rl_line_buffer}.
945: @end deftypefun
946:
947: @deftypefun int rl_forced_update_display (void)
948: Force the line to be updated and redisplayed, whether or not
949: Readline thinks the screen display is correct.
950: @end deftypefun
951:
952: @deftypefun int rl_on_new_line (void)
953: Tell the update functions that we have moved onto a new (empty) line,
954: usually after outputting a newline.
955: @end deftypefun
956:
957: @deftypefun int rl_on_new_line_with_prompt (void)
958: Tell the update functions that we have moved onto a new line, with
959: @var{rl_prompt} already displayed.
960: This could be used by applications that want to output the prompt string
961: themselves, but still need Readline to know the prompt string length for
962: redisplay.
963: It should be used after setting @var{rl_already_prompted}.
964: @end deftypefun
965:
966: @deftypefun int rl_reset_line_state (void)
967: Reset the display state to a clean state and redisplay the current line
968: starting on a new line.
969: @end deftypefun
970:
971: @deftypefun int rl_crlf (void)
972: Move the cursor to the start of the next screen line.
973: @end deftypefun
974:
975: @deftypefun int rl_show_char (int c)
976: Display character @var{c} on @code{rl_outstream}.
977: If Readline has not been set to display meta characters directly, this
978: will convert meta characters to a meta-prefixed key sequence.
979: This is intended for use by applications which wish to do their own
980: redisplay.
981: @end deftypefun
982:
983: @deftypefun int rl_message (const char *, @dots{})
984: The arguments are a format string as would be supplied to @code{printf},
985: possibly containing conversion specifications such as @samp{%d}, and
986: any additional arguments necessary to satisfy the conversion specifications.
987: The resulting string is displayed in the @dfn{echo area}. The echo area
988: is also used to display numeric arguments and search strings.
989: You should call @code{rl_save_prompt} to save the prompt information
990: before calling this function.
991: @end deftypefun
992:
993: @deftypefun int rl_clear_message (void)
994: Clear the message in the echo area. If the prompt was saved with a call to
995: @code{rl_save_prompt} before the last call to @code{rl_message},
996: call @code{rl_restore_prompt} before calling this function.
997: @end deftypefun
998:
999: @deftypefun void rl_save_prompt (void)
1000: Save the local Readline prompt display state in preparation for
1001: displaying a new message in the message area with @code{rl_message()}.
1002: @end deftypefun
1003:
1004: @deftypefun void rl_restore_prompt (void)
1005: Restore the local Readline prompt display state saved by the most
1006: recent call to @code{rl_save_prompt}.
1007: if @code{rl_save_prompt} was called to save the prompt before a call
1008: to @code{rl_message}, this function should be called before the
1009: corresponding call to @code{rl_clear_message}.
1010: @end deftypefun
1011:
1012: @deftypefun int rl_expand_prompt (char *prompt)
1013: Expand any special character sequences in @var{prompt} and set up the
1014: local Readline prompt redisplay variables.
1015: This function is called by @code{readline()}. It may also be called to
1016: expand the primary prompt if the @code{rl_on_new_line_with_prompt()}
1017: function or @code{rl_already_prompted} variable is used.
1018: It returns the number of visible characters on the last line of the
1019: (possibly multi-line) prompt.
1020: Applications may indicate that the prompt contains characters that take
1021: up no physical screen space when displayed by bracketing a sequence of
1022: such characters with the special markers @code{RL_PROMPT_START_IGNORE}
1023: and @code{RL_PROMPT_END_IGNORE} (declared in @file{readline.h}. This may
1024: be used to embed terminal-specific escape sequences in prompts.
1025: @end deftypefun
1026:
1027: @deftypefun int rl_set_prompt (const char *prompt)
1028: Make Readline use @var{prompt} for subsequent redisplay. This calls
1029: @code{rl_expand_prompt()} to expand the prompt and sets @code{rl_prompt}
1030: to the result.
1031: @end deftypefun
1032:
1033: @node Modifying Text
1034: @subsection Modifying Text
1035:
1036: @deftypefun int rl_insert_text (const char *text)
1037: Insert @var{text} into the line at the current cursor position.
1038: Returns the number of characters inserted.
1039: @end deftypefun
1040:
1041: @deftypefun int rl_delete_text (int start, int end)
1042: Delete the text between @var{start} and @var{end} in the current line.
1043: Returns the number of characters deleted.
1044: @end deftypefun
1045:
1046: @deftypefun {char *} rl_copy_text (int start, int end)
1047: Return a copy of the text between @var{start} and @var{end} in
1048: the current line.
1049: @end deftypefun
1050:
1051: @deftypefun int rl_kill_text (int start, int end)
1052: Copy the text between @var{start} and @var{end} in the current line
1053: to the kill ring, appending or prepending to the last kill if the
1054: last command was a kill command. The text is deleted.
1055: If @var{start} is less than @var{end},
1056: the text is appended, otherwise prepended. If the last command was
1057: not a kill, a new kill ring slot is used.
1058: @end deftypefun
1059:
1060: @deftypefun int rl_push_macro_input (char *macro)
1061: Cause @var{macro} to be inserted into the line, as if it had been invoked
1062: by a key bound to a macro. Not especially useful; use
1063: @code{rl_insert_text()} instead.
1064: @end deftypefun
1065:
1066: @node Character Input
1067: @subsection Character Input
1068:
1069: @deftypefun int rl_read_key (void)
1070: Return the next character available from Readline's current input stream.
1071: This handles input inserted into
1072: the input stream via @var{rl_pending_input} (@pxref{Readline Variables})
1073: and @code{rl_stuff_char()}, macros, and characters read from the keyboard.
1074: While waiting for input, this function will call any function assigned to
1075: the @code{rl_event_hook} variable.
1076: @end deftypefun
1077:
1078: @deftypefun int rl_getc (FILE *stream)
1079: Return the next character available from @var{stream}, which is assumed to
1080: be the keyboard.
1081: @end deftypefun
1082:
1083: @deftypefun int rl_stuff_char (int c)
1084: Insert @var{c} into the Readline input stream. It will be "read"
1085: before Readline attempts to read characters from the terminal with
1086: @code{rl_read_key()}. Up to 512 characters may be pushed back.
1087: @code{rl_stuff_char} returns 1 if the character was successfully inserted;
1088: 0 otherwise.
1089: @end deftypefun
1090:
1091: @deftypefun int rl_execute_next (int c)
1092: Make @var{c} be the next command to be executed when @code{rl_read_key()}
1093: is called. This sets @var{rl_pending_input}.
1094: @end deftypefun
1095:
1096: @deftypefun int rl_clear_pending_input (void)
1097: Unset @var{rl_pending_input}, effectively negating the effect of any
1098: previous call to @code{rl_execute_next()}. This works only if the
1099: pending input has not already been read with @code{rl_read_key()}.
1100: @end deftypefun
1101:
1102: @deftypefun int rl_set_keyboard_input_timeout (int u)
1103: While waiting for keyboard input in @code{rl_read_key()}, Readline will
1104: wait for @var{u} microseconds for input before calling any function
1105: assigned to @code{rl_event_hook}. @var{u} must be greater than or equal
1106: to zero (a zero-length timeout is equivalent to a poll).
1107: The default waiting period is one-tenth of a second.
1108: Returns the old timeout value.
1109: @end deftypefun
1110:
1111: @node Terminal Management
1112: @subsection Terminal Management
1113:
1114: @deftypefun void rl_prep_terminal (int meta_flag)
1115: Modify the terminal settings for Readline's use, so @code{readline()}
1116: can read a single character at a time from the keyboard.
1117: The @var{meta_flag} argument should be non-zero if Readline should
1118: read eight-bit input.
1119: @end deftypefun
1120:
1121: @deftypefun void rl_deprep_terminal (void)
1122: Undo the effects of @code{rl_prep_terminal()}, leaving the terminal in
1123: the state in which it was before the most recent call to
1124: @code{rl_prep_terminal()}.
1125: @end deftypefun
1126:
1127: @deftypefun void rl_tty_set_default_bindings (Keymap kmap)
1128: Read the operating system's terminal editing characters (as would be
1129: displayed by @code{stty}) to their Readline equivalents.
1130: The bindings are performed in @var{kmap}.
1131: @end deftypefun
1132:
1133: @deftypefun void rl_tty_unset_default_bindings (Keymap kmap)
1134: Reset the bindings manipulated by @code{rl_tty_set_default_bindings} so
1135: that the terminal editing characters are bound to @code{rl_insert}.
1136: The bindings are performed in @var{kmap}.
1137: @end deftypefun
1138:
1139: @deftypefun int rl_reset_terminal (const char *terminal_name)
1140: Reinitialize Readline's idea of the terminal settings using
1141: @var{terminal_name} as the terminal type (e.g., @code{vt100}).
1142: If @var{terminal_name} is @code{NULL}, the value of the @code{TERM}
1143: environment variable is used.
1144: @end deftypefun
1145:
1146: @node Utility Functions
1147: @subsection Utility Functions
1148:
1149: @deftypefun int rl_save_state (struct readline_state *sp)
1150: Save a snapshot of Readline's internal state to @var{sp}.
1151: The contents of the @var{readline_state} structure are documented
1152: in @file{readline.h}.
1153: The caller is responsible for allocating the structure.
1154: @end deftypefun
1155:
1156: @deftypefun int rl_restore_state (struct readline_state *sp)
1157: Restore Readline's internal state to that stored in @var{sp}, which must
1158: have been saved by a call to @code{rl_save_state}.
1159: The contents of the @var{readline_state} structure are documented
1160: in @file{readline.h}.
1161: The caller is responsible for freeing the structure.
1162: @end deftypefun
1163:
1164: @deftypefun void rl_free (void *mem)
1165: Deallocate the memory pointed to by @var{mem}. @var{mem} must have been
1166: allocated by @code{malloc}.
1167: @end deftypefun
1168:
1169: @deftypefun void rl_replace_line (const char *text, int clear_undo)
1170: Replace the contents of @code{rl_line_buffer} with @var{text}.
1171: The point and mark are preserved, if possible.
1172: If @var{clear_undo} is non-zero, the undo list associated with the
1173: current line is cleared.
1174: @end deftypefun
1175:
1176: @deftypefun void rl_extend_line_buffer (int len)
1177: Ensure that @code{rl_line_buffer} has enough space to hold @var{len}
1178: characters, possibly reallocating it if necessary.
1179: @end deftypefun
1180:
1181: @deftypefun int rl_initialize (void)
1182: Initialize or re-initialize Readline's internal state.
1183: It's not strictly necessary to call this; @code{readline()} calls it before
1184: reading any input.
1185: @end deftypefun
1186:
1187: @deftypefun int rl_ding (void)
1188: Ring the terminal bell, obeying the setting of @code{bell-style}.
1189: @end deftypefun
1190:
1191: @deftypefun int rl_alphabetic (int c)
1192: Return 1 if @var{c} is an alphabetic character.
1193: @end deftypefun
1194:
1195: @deftypefun void rl_display_match_list (char **matches, int len, int max)
1196: A convenience function for displaying a list of strings in
1197: columnar format on Readline's output stream. @code{matches} is the list
1198: of strings, in argv format, such as a list of completion matches.
1199: @code{len} is the number of strings in @code{matches}, and @code{max}
1200: is the length of the longest string in @code{matches}. This function uses
1201: the setting of @code{print-completions-horizontally} to select how the
1202: matches are displayed (@pxref{Readline Init File Syntax}).
1203: When displaying completions, this function sets the number of columns used
1204: for display to the value of @code{completion-display-width}, the value of
1205: the environment variable @env{COLUMNS}, or the screen width, in that order.
1206: @end deftypefun
1207:
1208: The following are implemented as macros, defined in @code{chardefs.h}.
1209: Applications should refrain from using them.
1210:
1211: @deftypefun int _rl_uppercase_p (int c)
1212: Return 1 if @var{c} is an uppercase alphabetic character.
1213: @end deftypefun
1214:
1215: @deftypefun int _rl_lowercase_p (int c)
1216: Return 1 if @var{c} is a lowercase alphabetic character.
1217: @end deftypefun
1218:
1219: @deftypefun int _rl_digit_p (int c)
1220: Return 1 if @var{c} is a numeric character.
1221: @end deftypefun
1222:
1223: @deftypefun int _rl_to_upper (int c)
1224: If @var{c} is a lowercase alphabetic character, return the corresponding
1225: uppercase character.
1226: @end deftypefun
1227:
1228: @deftypefun int _rl_to_lower (int c)
1229: If @var{c} is an uppercase alphabetic character, return the corresponding
1230: lowercase character.
1231: @end deftypefun
1232:
1233: @deftypefun int _rl_digit_value (int c)
1234: If @var{c} is a number, return the value it represents.
1235: @end deftypefun
1236:
1237: @node Miscellaneous Functions
1238: @subsection Miscellaneous Functions
1239:
1240: @deftypefun int rl_macro_bind (const char *keyseq, const char *macro, Keymap map)
1241: Bind the key sequence @var{keyseq} to invoke the macro @var{macro}.
1242: The binding is performed in @var{map}. When @var{keyseq} is invoked, the
1243: @var{macro} will be inserted into the line. This function is deprecated;
1244: use @code{rl_generic_bind()} instead.
1245: @end deftypefun
1246:
1247: @deftypefun void rl_macro_dumper (int readable)
1248: Print the key sequences bound to macros and their values, using
1249: the current keymap, to @code{rl_outstream}.
1250: If @var{readable} is non-zero, the list is formatted in such a way
1251: that it can be made part of an @code{inputrc} file and re-read.
1252: @end deftypefun
1253:
1254: @deftypefun int rl_variable_bind (const char *variable, const char *value)
1255: Make the Readline variable @var{variable} have @var{value}.
1256: This behaves as if the readline command
1257: @samp{set @var{variable} @var{value}} had been executed in an @code{inputrc}
1258: file (@pxref{Readline Init File Syntax}).
1259: @end deftypefun
1260:
1261: @deftypefun {char *} rl_variable_value (const char *variable)
1262: Return a string representing the value of the Readline variable @var{variable}.
1263: For boolean variables, this string is either @samp{on} or @samp{off}.
1264: @end deftypefun
1265:
1266: @deftypefun void rl_variable_dumper (int readable)
1267: Print the readline variable names and their current values
1268: to @code{rl_outstream}.
1269: If @var{readable} is non-zero, the list is formatted in such a way
1270: that it can be made part of an @code{inputrc} file and re-read.
1271: @end deftypefun
1272:
1273: @deftypefun int rl_set_paren_blink_timeout (int u)
1274: Set the time interval (in microseconds) that Readline waits when showing
1275: a balancing character when @code{blink-matching-paren} has been enabled.
1276: @end deftypefun
1277:
1278: @deftypefun {char *} rl_get_termcap (const char *cap)
1279: Retrieve the string value of the termcap capability @var{cap}.
1280: Readline fetches the termcap entry for the current terminal name and
1281: uses those capabilities to move around the screen line and perform other
1282: terminal-specific operations, like erasing a line. Readline does not
1283: use all of a terminal's capabilities, and this function will return
1284: values for only those capabilities Readline uses.
1285: @end deftypefun
1286:
1287: @deftypefun {void} rl_clear_history (void)
1288: Clear the history list by deleting all of the entries, in the same manner
1289: as the History library's @code{clear_history()} function.
1290: This differs from @code{clear_history} because it frees private data
1291: Readline saves in the history list.
1292: @end deftypefun
1293:
1294: @node Alternate Interface
1295: @subsection Alternate Interface
1296:
1297: An alternate interface is available to plain @code{readline()}. Some
1298: applications need to interleave keyboard I/O with file, device, or
1299: window system I/O, typically by using a main loop to @code{select()}
1300: on various file descriptors. To accommodate this need, readline can
1301: also be invoked as a `callback' function from an event loop. There
1302: are functions available to make this easy.
1303:
1304: @deftypefun void rl_callback_handler_install (const char *prompt, rl_vcpfunc_t *lhandler)
1305: Set up the terminal for readline I/O and display the initial
1306: expanded value of @var{prompt}. Save the value of @var{lhandler} to
1307: use as a handler function to call when a complete line of input has been
1308: entered.
1309: The handler function receives the text of the line as an argument.
1310: @end deftypefun
1311:
1312: @deftypefun void rl_callback_read_char (void)
1313: Whenever an application determines that keyboard input is available, it
1314: should call @code{rl_callback_read_char()}, which will read the next
1315: character from the current input source.
1316: If that character completes the line, @code{rl_callback_read_char} will
1317: invoke the @var{lhandler} function installed by
1318: @code{rl_callback_handler_install} to process the line.
1319: Before calling the @var{lhandler} function, the terminal settings are
1320: reset to the values they had before calling
1321: @code{rl_callback_handler_install}.
1322: If the @var{lhandler} function returns,
1323: and the line handler remains installed,
1324: the terminal settings are modified for Readline's use again.
1325: @code{EOF} is indicated by calling @var{lhandler} with a
1326: @code{NULL} line.
1327: @end deftypefun
1328:
1329: @deftypefun void rl_callback_handler_remove (void)
1330: Restore the terminal to its initial state and remove the line handler.
1331: This may be called from within a callback as well as independently.
1332: If the @var{lhandler} installed by @code{rl_callback_handler_install}
1333: does not exit the program, either this function or the function referred
1334: to by the value of @code{rl_deprep_term_function} should be called before
1335: the program exits to reset the terminal settings.
1336: @end deftypefun
1337:
1338: @node A Readline Example
1339: @subsection A Readline Example
1340:
1341: Here is a function which changes lowercase characters to their uppercase
1342: equivalents, and uppercase characters to lowercase. If
1343: this function was bound to @samp{M-c}, then typing @samp{M-c} would
1344: change the case of the character under point. Typing @samp{M-1 0 M-c}
1345: would change the case of the following 10 characters, leaving the cursor on
1346: the last character changed.
1347:
1348: @example
1349: /* Invert the case of the COUNT following characters. */
1350: int
1351: invert_case_line (count, key)
1352: int count, key;
1353: @{
1354: register int start, end, i;
1355:
1356: start = rl_point;
1357:
1358: if (rl_point >= rl_end)
1359: return (0);
1360:
1361: if (count < 0)
1362: @{
1363: direction = -1;
1364: count = -count;
1365: @}
1366: else
1367: direction = 1;
1368:
1369: /* Find the end of the range to modify. */
1370: end = start + (count * direction);
1371:
1372: /* Force it to be within range. */
1373: if (end > rl_end)
1374: end = rl_end;
1375: else if (end < 0)
1376: end = 0;
1377:
1378: if (start == end)
1379: return (0);
1380:
1381: if (start > end)
1382: @{
1383: int temp = start;
1384: start = end;
1385: end = temp;
1386: @}
1387:
1388: /* Tell readline that we are modifying the line,
1389: so it will save the undo information. */
1390: rl_modifying (start, end);
1391:
1392: for (i = start; i != end; i++)
1393: @{
1394: if (_rl_uppercase_p (rl_line_buffer[i]))
1395: rl_line_buffer[i] = _rl_to_lower (rl_line_buffer[i]);
1396: else if (_rl_lowercase_p (rl_line_buffer[i]))
1397: rl_line_buffer[i] = _rl_to_upper (rl_line_buffer[i]);
1398: @}
1399: /* Move point to on top of the last character changed. */
1400: rl_point = (direction == 1) ? end - 1 : start;
1401: return (0);
1402: @}
1403: @end example
1404:
1405: @node Alternate Interface Example
1406: @subsection Alternate Interface Example
1407:
1408: Here is a complete program that illustrates Readline's alternate interface.
1409: It reads lines from the terminal and displays them, providing the
1410: standard history and TAB completion functions.
1411: It understands the EOF character or "exit" to exit the program.
1412:
1413: @example
1414: /* Standard include files. stdio.h is required. */
1415: #include <stdlib.h>
1416: #include <unistd.h>
1417:
1418: /* Used for select(2) */
1419: #include <sys/types.h>
1420: #include <sys/select.h>
1421:
1422: #include <stdio.h>
1423:
1424: /* Standard readline include files. */
1425: #include <readline/readline.h>
1426: #include <readline/history.h>
1427:
1428: static void cb_linehandler (char *);
1429:
1430: int running;
1431: const char *prompt = "rltest$ ";
1432:
1433: /* Callback function called for each line when accept-line executed, EOF
1434: seen, or EOF character read. This sets a flag and returns; it could
1435: also call exit(3). */
1436: static void
1437: cb_linehandler (char *line)
1438: @{
1439: /* Can use ^D (stty eof) or `exit' to exit. */
1440: if (line == NULL || strcmp (line, "exit") == 0)
1441: @{
1442: if (line == 0)
1443: printf ("\n");
1444: printf ("exit\n");
1445: /* This function needs to be called to reset the terminal settings,
1446: and calling it from the line handler keeps one extra prompt from
1447: being displayed. */
1448: rl_callback_handler_remove ();
1449:
1450: running = 0;
1451: @}
1452: else
1453: @{
1454: if (*line)
1455: add_history (line);
1456: printf ("input line: %s\n", line);
1457: free (line);
1458: @}
1459: @}
1460:
1461: int
1462: main (int c, char **v)
1463: @{
1464: fd_set fds;
1465: int r;
1466:
1467: /* Install the line handler. */
1468: rl_callback_handler_install (prompt, cb_linehandler);
1469:
1470: /* Enter a simple event loop. This waits until something is available
1471: to read on readline's input stream (defaults to standard input) and
1472: calls the builtin character read callback to read it. It does not
1473: have to modify the user's terminal settings. */
1474: running = 1;
1475: while (running)
1476: @{
1477: FD_ZERO (&fds);
1478: FD_SET (fileno (rl_instream), &fds);
1479:
1480: r = select (FD_SETSIZE, &fds, NULL, NULL, NULL);
1481: if (r < 0)
1482: @{
1483: perror ("rltest: select");
1484: rl_callback_handler_remove ();
1485: break;
1486: @}
1487:
1488: if (FD_ISSET (fileno (rl_instream), &fds))
1489: rl_callback_read_char ();
1490: @}
1491:
1492: printf ("rltest: Event loop has exited\n");
1493: return 0;
1494: @}
1495: @end example
1496:
1497: @node Readline Signal Handling
1498: @section Readline Signal Handling
1499:
1500: Signals are asynchronous events sent to a process by the Unix kernel,
1501: sometimes on behalf of another process. They are intended to indicate
1502: exceptional events, like a user pressing the interrupt key on his terminal,
1503: or a network connection being broken. There is a class of signals that can
1504: be sent to the process currently reading input from the keyboard. Since
1505: Readline changes the terminal attributes when it is called, it needs to
1506: perform special processing when such a signal is received in order to
1507: restore the terminal to a sane state, or provide application writers with
1508: functions to do so manually.
1509:
1510: Readline contains an internal signal handler that is installed for a
1511: number of signals (@code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM},
1512: @code{SIGHUP},
1513: @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}).
1514: When one of these signals is received, the signal handler
1515: will reset the terminal attributes to those that were in effect before
1516: @code{readline()} was called, reset the signal handling to what it was
1517: before @code{readline()} was called, and resend the signal to the calling
1518: application.
1519: If and when the calling application's signal handler returns, Readline
1520: will reinitialize the terminal and continue to accept input.
1521: When a @code{SIGINT} is received, the Readline signal handler performs
1522: some additional work, which will cause any partially-entered line to be
1523: aborted (see the description of @code{rl_free_line_state()} below).
1524:
1525: There is an additional Readline signal handler, for @code{SIGWINCH}, which
1526: the kernel sends to a process whenever the terminal's size changes (for
1527: example, if a user resizes an @code{xterm}). The Readline @code{SIGWINCH}
1528: handler updates Readline's internal screen size information, and then calls
1529: any @code{SIGWINCH} signal handler the calling application has installed.
1530: Readline calls the application's @code{SIGWINCH} signal handler without
1531: resetting the terminal to its original state. If the application's signal
1532: handler does more than update its idea of the terminal size and return (for
1533: example, a @code{longjmp} back to a main processing loop), it @emph{must}
1534: call @code{rl_cleanup_after_signal()} (described below), to restore the
1535: terminal state.
1536:
1537: Readline provides two variables that allow application writers to
1538: control whether or not it will catch certain signals and act on them
1539: when they are received. It is important that applications change the
1540: values of these variables only when calling @code{readline()}, not in
1541: a signal handler, so Readline's internal signal state is not corrupted.
1542:
1543: @deftypevar int rl_catch_signals
1544: If this variable is non-zero, Readline will install signal handlers for
1545: @code{SIGINT}, @code{SIGQUIT}, @code{SIGTERM}, @code{SIGHUP}, @code{SIGALRM},
1546: @code{SIGTSTP}, @code{SIGTTIN}, and @code{SIGTTOU}.
1547:
1548: The default value of @code{rl_catch_signals} is 1.
1549: @end deftypevar
1550:
1551: @deftypevar int rl_catch_sigwinch
1552: If this variable is set to a non-zero value,
1553: Readline will install a signal handler for @code{SIGWINCH}.
1554:
1555: The default value of @code{rl_catch_sigwinch} is 1.
1556: @end deftypevar
1557:
1558: @deftypevar int rl_change_environment
1559: If this variable is set to a non-zero value,
1560: and Readline is handling @code{SIGWINCH}, Readline will modify the
1561: @var{LINES} and @var{COLUMNS} environment variables upon receipt of a
1562: @code{SIGWINCH}
1563:
1564: The default value of @code{rl_change_environment} is 1.
1565: @end deftypevar
1566:
1567: If an application does not wish to have Readline catch any signals, or
1568: to handle signals other than those Readline catches (@code{SIGHUP},
1569: for example),
1570: Readline provides convenience functions to do the necessary terminal
1571: and internal state cleanup upon receipt of a signal.
1572:
1573: @deftypefun void rl_cleanup_after_signal (void)
1574: This function will reset the state of the terminal to what it was before
1575: @code{readline()} was called, and remove the Readline signal handlers for
1576: all signals, depending on the values of @code{rl_catch_signals} and
1577: @code{rl_catch_sigwinch}.
1578: @end deftypefun
1579:
1580: @deftypefun void rl_free_line_state (void)
1581: This will free any partial state associated with the current input line
1582: (undo information, any partial history entry, any partially-entered
1583: keyboard macro, and any partially-entered numeric argument). This
1584: should be called before @code{rl_cleanup_after_signal()}. The
1585: Readline signal handler for @code{SIGINT} calls this to abort the
1586: current input line.
1587: @end deftypefun
1588:
1589: @deftypefun void rl_reset_after_signal (void)
1590: This will reinitialize the terminal and reinstall any Readline signal
1591: handlers, depending on the values of @code{rl_catch_signals} and
1592: @code{rl_catch_sigwinch}.
1593: @end deftypefun
1594:
1595: If an application does not wish Readline to catch @code{SIGWINCH}, it may
1596: call @code{rl_resize_terminal()} or @code{rl_set_screen_size()} to force
1597: Readline to update its idea of the terminal size when a @code{SIGWINCH}
1598: is received.
1599:
1600: @deftypefun void rl_echo_signal_char (int sig)
1601: If an application wishes to install its own signal handlers, but still
1602: have readline display characters that generate signals, calling this
1603: function with @var{sig} set to @code{SIGINT}, @code{SIGQUIT}, or
1604: @code{SIGTSTP} will display the character generating that signal.
1605: @end deftypefun
1606:
1607: @deftypefun void rl_resize_terminal (void)
1608: Update Readline's internal screen size by reading values from the kernel.
1609: @end deftypefun
1610:
1611: @deftypefun void rl_set_screen_size (int rows, int cols)
1612: Set Readline's idea of the terminal size to @var{rows} rows and
1613: @var{cols} columns. If either @var{rows} or @var{columns} is less than
1614: or equal to 0, Readline's idea of that terminal dimension is unchanged.
1615: @end deftypefun
1616:
1617: If an application does not want to install a @code{SIGWINCH} handler, but
1618: is still interested in the screen dimensions, Readline's idea of the screen
1619: size may be queried.
1620:
1621: @deftypefun void rl_get_screen_size (int *rows, int *cols)
1622: Return Readline's idea of the terminal's size in the
1623: variables pointed to by the arguments.
1624: @end deftypefun
1625:
1626: @deftypefun void rl_reset_screen_size (void)
1627: Cause Readline to reobtain the screen size and recalculate its dimensions.
1628: @end deftypefun
1629:
1630: The following functions install and remove Readline's signal handlers.
1631:
1632: @deftypefun int rl_set_signals (void)
1633: Install Readline's signal handler for @code{SIGINT}, @code{SIGQUIT},
1634: @code{SIGTERM}, @code{SIGHUP}, @code{SIGALRM}, @code{SIGTSTP}, @code{SIGTTIN},
1635: @code{SIGTTOU}, and @code{SIGWINCH}, depending on the values of
1636: @code{rl_catch_signals} and @code{rl_catch_sigwinch}.
1637: @end deftypefun
1638:
1639: @deftypefun int rl_clear_signals (void)
1640: Remove all of the Readline signal handlers installed by
1641: @code{rl_set_signals()}.
1642: @end deftypefun
1643:
1644: @node Custom Completers
1645: @section Custom Completers
1646: @cindex application-specific completion functions
1647:
1648: Typically, a program that reads commands from the user has a way of
1649: disambiguating commands and data. If your program is one of these, then
1650: it can provide completion for commands, data, or both.
1651: The following sections describe how your program and Readline
1652: cooperate to provide this service.
1653:
1654: @menu
1655: * How Completing Works:: The logic used to do completion.
1656: * Completion Functions:: Functions provided by Readline.
1657: * Completion Variables:: Variables which control completion.
1658: * A Short Completion Example:: An example of writing completer subroutines.
1659: @end menu
1660:
1661: @node How Completing Works
1662: @subsection How Completing Works
1663:
1664: In order to complete some text, the full list of possible completions
1665: must be available. That is, it is not possible to accurately
1666: expand a partial word without knowing all of the possible words
1667: which make sense in that context. The Readline library provides
1668: the user interface to completion, and two of the most common
1669: completion functions: filename and username. For completing other types
1670: of text, you must write your own completion function. This section
1671: describes exactly what such functions must do, and provides an example.
1672:
1673: There are three major functions used to perform completion:
1674:
1675: @enumerate
1676: @item
1677: The user-interface function @code{rl_complete()}. This function is
1678: called with the same arguments as other bindable Readline functions:
1679: @var{count} and @var{invoking_key}.
1680: It isolates the word to be completed and calls
1681: @code{rl_completion_matches()} to generate a list of possible completions.
1682: It then either lists the possible completions, inserts the possible
1683: completions, or actually performs the
1684: completion, depending on which behavior is desired.
1685:
1686: @item
1687: The internal function @code{rl_completion_matches()} uses an
1688: application-supplied @dfn{generator} function to generate the list of
1689: possible matches, and then returns the array of these matches.
1690: The caller should place the address of its generator function in
1691: @code{rl_completion_entry_function}.
1692:
1693: @item
1694: The generator function is called repeatedly from
1695: @code{rl_completion_matches()}, returning a string each time. The
1696: arguments to the generator function are @var{text} and @var{state}.
1697: @var{text} is the partial word to be completed. @var{state} is zero the
1698: first time the function is called, allowing the generator to perform
1699: any necessary initialization, and a positive non-zero integer for
1700: each subsequent call. The generator function returns
1701: @code{(char *)NULL} to inform @code{rl_completion_matches()} that there are
1702: no more possibilities left. Usually the generator function computes the
1703: list of possible completions when @var{state} is zero, and returns them
1704: one at a time on subsequent calls. Each string the generator function
1705: returns as a match must be allocated with @code{malloc()}; Readline
1706: frees the strings when it has finished with them.
1707: Such a generator function is referred to as an
1708: @dfn{application-specific completion function}.
1709:
1710: @end enumerate
1711:
1712: @deftypefun int rl_complete (int ignore, int invoking_key)
1713: Complete the word at or before point. You have supplied the function
1714: that does the initial simple matching selection algorithm (see
1715: @code{rl_completion_matches()}). The default is to do filename completion.
1716: @end deftypefun
1717:
1718: @deftypevar {rl_compentry_func_t *} rl_completion_entry_function
1719: This is a pointer to the generator function for
1720: @code{rl_completion_matches()}.
1721: If the value of @code{rl_completion_entry_function} is
1722: @code{NULL} then the default filename generator
1723: function, @code{rl_filename_completion_function()}, is used.
1724: An @dfn{application-specific completion function} is a function whose
1725: address is assigned to @code{rl_completion_entry_function} and whose
1726: return values are used to generate possible completions.
1727: @end deftypevar
1728:
1729: @node Completion Functions
1730: @subsection Completion Functions
1731:
1732: Here is the complete list of callable completion functions present in
1733: Readline.
1734:
1735: @deftypefun int rl_complete_internal (int what_to_do)
1736: Complete the word at or before point. @var{what_to_do} says what to do
1737: with the completion. A value of @samp{?} means list the possible
1738: completions. @samp{TAB} means do standard completion. @samp{*} means
1739: insert all of the possible completions. @samp{!} means to display
1740: all of the possible completions, if there is more than one, as well as
1741: performing partial completion. @samp{@@} is similar to @samp{!}, but
1742: possible completions are not listed if the possible completions share
1743: a common prefix.
1744: @end deftypefun
1745:
1746: @deftypefun int rl_complete (int ignore, int invoking_key)
1747: Complete the word at or before point. You have supplied the function
1748: that does the initial simple matching selection algorithm (see
1749: @code{rl_completion_matches()} and @code{rl_completion_entry_function}).
1750: The default is to do filename
1751: completion. This calls @code{rl_complete_internal()} with an
1752: argument depending on @var{invoking_key}.
1753: @end deftypefun
1754:
1755: @deftypefun int rl_possible_completions (int count, int invoking_key)
1756: List the possible completions. See description of @code{rl_complete
1757: ()}. This calls @code{rl_complete_internal()} with an argument of
1758: @samp{?}.
1759: @end deftypefun
1760:
1761: @deftypefun int rl_insert_completions (int count, int invoking_key)
1762: Insert the list of possible completions into the line, deleting the
1763: partially-completed word. See description of @code{rl_complete()}.
1764: This calls @code{rl_complete_internal()} with an argument of @samp{*}.
1765: @end deftypefun
1766:
1767: @deftypefun int rl_completion_mode (rl_command_func_t *cfunc)
1768: Returns the appropriate value to pass to @code{rl_complete_internal()}
1769: depending on whether @var{cfunc} was called twice in succession and
1770: the values of the @code{show-all-if-ambiguous} and
1771: @code{show-all-if-unmodified} variables.
1772: Application-specific completion functions may use this function to present
1773: the same interface as @code{rl_complete()}.
1774: @end deftypefun
1775:
1776: @deftypefun {char **} rl_completion_matches (const char *text, rl_compentry_func_t *entry_func)
1777: Returns an array of strings which is a list of completions for
1778: @var{text}. If there are no completions, returns @code{NULL}.
1779: The first entry in the returned array is the substitution for @var{text}.
1780: The remaining entries are the possible completions. The array is
1781: terminated with a @code{NULL} pointer.
1782:
1783: @var{entry_func} is a function of two args, and returns a
1784: @code{char *}. The first argument is @var{text}. The second is a
1785: state argument; it is zero on the first call, and non-zero on subsequent
1786: calls. @var{entry_func} returns a @code{NULL} pointer to the caller
1787: when there are no more matches.
1788: @end deftypefun
1789:
1790: @deftypefun {char *} rl_filename_completion_function (const char *text, int state)
1791: A generator function for filename completion in the general case.
1792: @var{text} is a partial filename.
1793: The Bash source is a useful reference for writing application-specific
1794: completion functions (the Bash completion functions call this and other
1795: Readline functions).
1796: @end deftypefun
1797:
1798: @deftypefun {char *} rl_username_completion_function (const char *text, int state)
1799: A completion generator for usernames. @var{text} contains a partial
1800: username preceded by a random character (usually @samp{~}). As with all
1801: completion generators, @var{state} is zero on the first call and non-zero
1802: for subsequent calls.
1803: @end deftypefun
1804:
1805: @node Completion Variables
1806: @subsection Completion Variables
1807:
1808: @deftypevar {rl_compentry_func_t *} rl_completion_entry_function
1809: A pointer to the generator function for @code{rl_completion_matches()}.
1810: @code{NULL} means to use @code{rl_filename_completion_function()},
1811: the default filename completer.
1812: @end deftypevar
1813:
1814: @deftypevar {rl_completion_func_t *} rl_attempted_completion_function
1815: A pointer to an alternative function to create matches.
1816: The function is called with @var{text}, @var{start}, and @var{end}.
1817: @var{start} and @var{end} are indices in @code{rl_line_buffer} defining
1818: the boundaries of @var{text}, which is a character string.
1819: If this function exists and returns @code{NULL}, or if this variable is
1820: set to @code{NULL}, then @code{rl_complete()} will call the value of
1821: @code{rl_completion_entry_function} to generate matches, otherwise the
1822: array of strings returned will be used.
1823: If this function sets the @code{rl_attempted_completion_over}
1824: variable to a non-zero value, Readline will not perform its default
1825: completion even if this function returns no matches.
1826: @end deftypevar
1827:
1828: @deftypevar {rl_quote_func_t *} rl_filename_quoting_function
1829: A pointer to a function that will quote a filename in an
1830: application-specific fashion. This is called if filename completion is being
1831: attempted and one of the characters in @code{rl_filename_quote_characters}
1832: appears in a completed filename. The function is called with
1833: @var{text}, @var{match_type}, and @var{quote_pointer}. The @var{text}
1834: is the filename to be quoted. The @var{match_type} is either
1835: @code{SINGLE_MATCH}, if there is only one completion match, or
1836: @code{MULT_MATCH}. Some functions use this to decide whether or not to
1837: insert a closing quote character. The @var{quote_pointer} is a pointer
1838: to any opening quote character the user typed. Some functions choose
1839: to reset this character.
1840: @end deftypevar
1841:
1842: @deftypevar {rl_dequote_func_t *} rl_filename_dequoting_function
1843: A pointer to a function that will remove application-specific quoting
1844: characters from a filename before completion is attempted, so those
1845: characters do not interfere with matching the text against names in
1846: the filesystem. It is called with @var{text}, the text of the word
1847: to be dequoted, and @var{quote_char}, which is the quoting character
1848: that delimits the filename (usually @samp{'} or @samp{"}). If
1849: @var{quote_char} is zero, the filename was not in an embedded string.
1850: @end deftypevar
1851:
1852: @deftypevar {rl_linebuf_func_t *} rl_char_is_quoted_p
1853: A pointer to a function to call that determines whether or not a specific
1854: character in the line buffer is quoted, according to whatever quoting
1855: mechanism the program calling Readline uses. The function is called with
1856: two arguments: @var{text}, the text of the line, and @var{index}, the
1857: index of the character in the line. It is used to decide whether a
1858: character found in @code{rl_completer_word_break_characters} should be
1859: used to break words for the completer.
1860: @end deftypevar
1861:
1862: @deftypevar {rl_compignore_func_t *} rl_ignore_some_completions_function
1863: This function, if defined, is called by the completer when real filename
1864: completion is done, after all the matching names have been generated.
1865: It is passed a @code{NULL} terminated array of matches.
1866: The first element (@code{matches[0]}) is the
1867: maximal substring common to all matches. This function can
1868: re-arrange the list of matches as required, but each element deleted
1869: from the array must be freed.
1870: @end deftypevar
1871:
1872: @deftypevar {rl_icppfunc_t *} rl_directory_completion_hook
1873: This function, if defined, is allowed to modify the directory portion
1874: of filenames Readline completes.
1875: It could be used to expand symbolic links or shell variables in pathnames.
1876: It is called with the address of a string (the current directory name) as an
1877: argument, and may modify that string.
1878: If the string is replaced with a new string, the old value should be freed.
1879: Any modified directory name should have a trailing slash.
1880: The modified value will be used as part of the completion, replacing
1881: the directory portion of the pathname the user typed.
1882: At the least, even if no other expansion is performed, this function should
1883: remove any quote characters from the directory name, because its result will
1884: be passed directly to @code{opendir()}.
1885:
1886: The directory completion hook returns an integer that should be non-zero if
1887: the function modifies its directory argument.
1888: The function should not modify the directory argument if it returns 0.
1889: @end deftypevar
1890:
1891: @deftypevar {rl_icppfunc_t *} rl_directory_rewrite_hook;
1892: If non-zero, this is the address of a function to call when completing
1893: a directory name. This function takes the address of the directory name
1894: to be modified as an argument. Unlike @code{rl_directory_completion_hook},
1895: it only modifies the directory name used in @code{opendir}, not what is
1896: displayed when the possible completions are printed or inserted. It is
1897: called before rl_directory_completion_hook.
1898: At the least, even if no other expansion is performed, this function should
1899: remove any quote characters from the directory name, because its result will
1900: be passed directly to @code{opendir()}.
1901:
1902: The directory rewrite hook returns an integer that should be non-zero if
1903: the function modfies its directory argument.
1904: The function should not modify the directory argument if it returns 0.
1905: @end deftypevar
1906:
1907: @deftypevar {rl_icppfunc_t *} rl_filename_stat_hook
1908: If non-zero, this is the address of a function for the completer to
1909: call before deciding which character to append to a completed name.
1910: This function modifies its filename name argument, and the modified value
1911: is passed to @code{stat()} to determine the file's type and characteristics.
1912: This function does not need to remove quote characters from the filename.
1913:
1914: The stat hook returns an integer that should be non-zero if
1915: the function modfies its directory argument.
1916: The function should not modify the directory argument if it returns 0.
1917: @end deftypevar
1918:
1919: @deftypevar {rl_dequote_func_t *} rl_filename_rewrite_hook
1920: If non-zero, this is the address of a function called when reading
1921: directory entries from the filesystem for completion and comparing
1922: them to the partial word to be completed. The function should
1923: perform any necessary application or system-specific conversion on
1924: the filename, such as converting between character sets or converting
1925: from a filesystem format to a character input format.
1926: The function takes two arguments: @var{fname}, the filename to be converted,
1927: and @var{fnlen}, its length in bytes.
1928: It must either return its first argument (if no conversion takes place)
1929: or the converted filename in newly-allocated memory. The converted
1930: form is used to compare against the word to be completed, and, if it
1931: matches, is added to the list of matches. Readline will free the
1932: allocated string.
1933: @end deftypevar
1934:
1935: @deftypevar {rl_compdisp_func_t *} rl_completion_display_matches_hook
1936: If non-zero, then this is the address of a function to call when
1937: completing a word would normally display the list of possible matches.
1938: This function is called in lieu of Readline displaying the list.
1939: It takes three arguments:
1940: (@code{char **}@var{matches}, @code{int} @var{num_matches}, @code{int} @var{max_length})
1941: where @var{matches} is the array of matching strings,
1942: @var{num_matches} is the number of strings in that array, and
1943: @var{max_length} is the length of the longest string in that array.
1944: Readline provides a convenience function, @code{rl_display_match_list},
1945: that takes care of doing the display to Readline's output stream. That
1946: function may be called from this hook.
1947: @end deftypevar
1948:
1949: @deftypevar {const char *} rl_basic_word_break_characters
1950: The basic list of characters that signal a break between words for the
1951: completer routine. The default value of this variable is the characters
1952: which break words for completion in Bash:
1953: @code{" \t\n\"\\'`@@$><=;|&@{("}.
1954: @end deftypevar
1955:
1956: @deftypevar {const char *} rl_basic_quote_characters
1957: A list of quote characters which can cause a word break.
1958: @end deftypevar
1959:
1960: @deftypevar {const char *} rl_completer_word_break_characters
1961: The list of characters that signal a break between words for
1962: @code{rl_complete_internal()}. The default list is the value of
1963: @code{rl_basic_word_break_characters}.
1964: @end deftypevar
1965:
1966: @deftypevar {rl_cpvfunc_t *} rl_completion_word_break_hook
1967: If non-zero, this is the address of a function to call when Readline is
1968: deciding where to separate words for word completion. It should return
1969: a character string like @code{rl_completer_word_break_characters} to be
1970: used to perform the current completion. The function may choose to set
1971: @code{rl_completer_word_break_characters} itself. If the function
1972: returns @code{NULL}, @code{rl_completer_word_break_characters} is used.
1973: @end deftypevar
1974:
1975: @deftypevar {const char *} rl_completer_quote_characters
1976: A list of characters which can be used to quote a substring of the line.
1977: Completion occurs on the entire substring, and within the substring
1978: @code{rl_completer_word_break_characters} are treated as any other character,
1979: unless they also appear within this list.
1980: @end deftypevar
1981:
1982: @deftypevar {const char *} rl_filename_quote_characters
1983: A list of characters that cause a filename to be quoted by the completer
1984: when they appear in a completed filename. The default is the null string.
1985: @end deftypevar
1986:
1987: @deftypevar {const char *} rl_special_prefixes
1988: The list of characters that are word break characters, but should be
1989: left in @var{text} when it is passed to the completion function.
1990: Programs can use this to help determine what kind of completing to do.
1991: For instance, Bash sets this variable to "$@@" so that it can complete
1992: shell variables and hostnames.
1993: @end deftypevar
1994:
1995: @deftypevar int rl_completion_query_items
1996: Up to this many items will be displayed in response to a
1997: possible-completions call. After that, readline asks the user if she is sure
1998: she wants to see them all. The default value is 100. A negative value
1999: indicates that Readline should never ask the user.
2000: @end deftypevar
2001:
2002: @deftypevar {int} rl_completion_append_character
2003: When a single completion alternative matches at the end of the command
2004: line, this character is appended to the inserted completion text. The
2005: default is a space character (@samp{ }). Setting this to the null
2006: character (@samp{\0}) prevents anything being appended automatically.
2007: This can be changed in application-specific completion functions to
2008: provide the ``most sensible word separator character'' according to
2009: an application-specific command line syntax specification.
2010: @end deftypevar
2011:
2012: @deftypevar int rl_completion_suppress_append
2013: If non-zero, @var{rl_completion_append_character} is not appended to
2014: matches at the end of the command line, as described above.
2015: It is set to 0 before any application-specific completion function
2016: is called, and may only be changed within such a function.
2017: @end deftypevar
2018:
2019: @deftypevar int rl_completion_quote_character
2020: When Readline is completing quoted text, as delimited by one of the
2021: characters in @var{rl_completer_quote_characters}, it sets this variable
2022: to the quoting character found.
2023: This is set before any application-specific completion function is called.
2024: @end deftypevar
2025:
2026: @deftypevar int rl_completion_suppress_quote
2027: If non-zero, Readline does not append a matching quote character when
2028: performing completion on a quoted string.
2029: It is set to 0 before any application-specific completion function
2030: is called, and may only be changed within such a function.
2031: @end deftypevar
2032:
2033: @deftypevar int rl_completion_found_quote
2034: When Readline is completing quoted text, it sets this variable
2035: to a non-zero value if the word being completed contains or is delimited
2036: by any quoting characters, including backslashes.
2037: This is set before any application-specific completion function is called.
2038: @end deftypevar
2039:
2040: @deftypevar int rl_completion_mark_symlink_dirs
2041: If non-zero, a slash will be appended to completed filenames that are
2042: symbolic links to directory names, subject to the value of the
2043: user-settable @var{mark-directories} variable.
2044: This variable exists so that application-specific completion functions
2045: can override the user's global preference (set via the
2046: @var{mark-symlinked-directories} Readline variable) if appropriate.
2047: This variable is set to the user's preference before any
2048: application-specific completion function is called, so unless that
2049: function modifies the value, the user's preferences are honored.
2050: @end deftypevar
2051:
2052: @deftypevar int rl_ignore_completion_duplicates
2053: If non-zero, then duplicates in the matches are removed.
2054: The default is 1.
2055: @end deftypevar
2056:
2057: @deftypevar int rl_filename_completion_desired
2058: Non-zero means that the results of the matches are to be treated as
2059: filenames. This is @emph{always} zero when completion is attempted,
2060: and can only be changed
2061: within an application-specific completion function. If it is set to a
2062: non-zero value by such a function, directory names have a slash appended
2063: and Readline attempts to quote completed filenames if they contain any
2064: characters in @code{rl_filename_quote_characters} and
2065: @code{rl_filename_quoting_desired} is set to a non-zero value.
2066: @end deftypevar
2067:
2068: @deftypevar int rl_filename_quoting_desired
2069: Non-zero means that the results of the matches are to be quoted using
2070: double quotes (or an application-specific quoting mechanism) if the
2071: completed filename contains any characters in
2072: @code{rl_filename_quote_chars}. This is @emph{always} non-zero
2073: when completion is attempted, and can only be changed within an
2074: application-specific completion function.
2075: The quoting is effected via a call to the function pointed to
2076: by @code{rl_filename_quoting_function}.
2077: @end deftypevar
2078:
2079: @deftypevar int rl_attempted_completion_over
2080: If an application-specific completion function assigned to
2081: @code{rl_attempted_completion_function} sets this variable to a non-zero
2082: value, Readline will not perform its default filename completion even
2083: if the application's completion function returns no matches.
2084: It should be set only by an application's completion function.
2085: @end deftypevar
2086:
2087: @deftypevar int rl_sort_completion_matches
2088: If an application sets this variable to 0, Readline will not sort the
2089: list of completions (which implies that it cannot remove any duplicate
2090: completions). The default value is 1, which means that Readline will
2091: sort the completions and, depending on the value of
2092: @code{rl_ignore_completion_duplicates}, will attempt to remove duplicate
2093: matches.
2094: @end deftypevar
2095:
2096: @deftypevar int rl_completion_type
2097: Set to a character describing the type of completion Readline is currently
2098: attempting; see the description of @code{rl_complete_internal()}
2099: (@pxref{Completion Functions}) for the list of characters.
2100: This is set to the appropriate value before any application-specific
2101: completion function is called, allowing such functions to present
2102: the same interface as @code{rl_complete()}.
2103: @end deftypevar
2104:
2105: @deftypevar int rl_completion_invoking_key
2106: Set to the final character in the key sequence that invoked one of the
2107: completion functions that call @code{rl_complete_internal()}. This is
2108: set to the appropriate value before any application-specific completion
2109: function is called.
2110: @end deftypevar
2111:
2112: @deftypevar int rl_inhibit_completion
2113: If this variable is non-zero, completion is inhibited. The completion
2114: character will be inserted as any other bound to @code{self-insert}.
2115: @end deftypevar
2116:
2117: @node A Short Completion Example
2118: @subsection A Short Completion Example
2119:
2120: Here is a small application demonstrating the use of the GNU Readline
2121: library. It is called @code{fileman}, and the source code resides in
2122: @file{examples/fileman.c}. This sample application provides
2123: completion of command names, line editing features, and access to the
2124: history list.
2125:
2126: @page
2127: @smallexample
2128: /* fileman.c -- A tiny application which demonstrates how to use the
2129: GNU Readline library. This application interactively allows users
2130: to manipulate files and their modes. */
2131:
2132: #ifdef HAVE_CONFIG_H
2133: # include <config.h>
2134: #endif
2135:
2136: #include <sys/types.h>
2137: #ifdef HAVE_SYS_FILE_H
2138: # include <sys/file.h>
2139: #endif
2140: #include <sys/stat.h>
2141:
2142: #ifdef HAVE_UNISTD_H
2143: # include <unistd.h>
2144: #endif
2145:
2146: #include <fcntl.h>
2147: #include <stdio.h>
2148: #include <errno.h>
2149:
2150: #if defined (HAVE_STRING_H)
2151: # include <string.h>
2152: #else /* !HAVE_STRING_H */
2153: # include <strings.h>
2154: #endif /* !HAVE_STRING_H */
2155:
2156: #ifdef HAVE_STDLIB_H
2157: # include <stdlib.h>
2158: #endif
2159:
2160: #include <time.h>
2161:
2162: #include <readline/readline.h>
2163: #include <readline/history.h>
2164:
2165: extern char *xmalloc PARAMS((size_t));
2166:
2167: /* The names of functions that actually do the manipulation. */
2168: int com_list PARAMS((char *));
2169: int com_view PARAMS((char *));
2170: int com_rename PARAMS((char *));
2171: int com_stat PARAMS((char *));
2172: int com_pwd PARAMS((char *));
2173: int com_delete PARAMS((char *));
2174: int com_help PARAMS((char *));
2175: int com_cd PARAMS((char *));
2176: int com_quit PARAMS((char *));
2177:
2178: /* A structure which contains information on the commands this program
2179: can understand. */
2180:
2181: typedef struct @{
2182: char *name; /* User printable name of the function. */
2183: rl_icpfunc_t *func; /* Function to call to do the job. */
2184: char *doc; /* Documentation for this function. */
2185: @} COMMAND;
2186:
2187: COMMAND commands[] = @{
2188: @{ "cd", com_cd, "Change to directory DIR" @},
2189: @{ "delete", com_delete, "Delete FILE" @},
2190: @{ "help", com_help, "Display this text" @},
2191: @{ "?", com_help, "Synonym for `help'" @},
2192: @{ "list", com_list, "List files in DIR" @},
2193: @{ "ls", com_list, "Synonym for `list'" @},
2194: @{ "pwd", com_pwd, "Print the current working directory" @},
2195: @{ "quit", com_quit, "Quit using Fileman" @},
2196: @{ "rename", com_rename, "Rename FILE to NEWNAME" @},
2197: @{ "stat", com_stat, "Print out statistics on FILE" @},
2198: @{ "view", com_view, "View the contents of FILE" @},
2199: @{ (char *)NULL, (rl_icpfunc_t *)NULL, (char *)NULL @}
2200: @};
2201:
2202: /* Forward declarations. */
2203: char *stripwhite ();
2204: COMMAND *find_command ();
2205:
2206: /* The name of this program, as taken from argv[0]. */
2207: char *progname;
2208:
2209: /* When non-zero, this global means the user is done using this program. */
2210: int done;
2211:
2212: char *
2213: dupstr (s)
2214: char *s;
2215: @{
2216: char *r;
2217:
2218: r = xmalloc (strlen (s) + 1);
2219: strcpy (r, s);
2220: return (r);
2221: @}
2222:
2223: main (argc, argv)
2224: int argc;
2225: char **argv;
2226: @{
2227: char *line, *s;
2228:
2229: progname = argv[0];
2230:
2231: initialize_readline (); /* Bind our completer. */
2232:
2233: /* Loop reading and executing lines until the user quits. */
2234: for ( ; done == 0; )
2235: @{
2236: line = readline ("FileMan: ");
2237:
2238: if (!line)
2239: break;
2240:
2241: /* Remove leading and trailing whitespace from the line.
2242: Then, if there is anything left, add it to the history list
2243: and execute it. */
2244: s = stripwhite (line);
2245:
2246: if (*s)
2247: @{
2248: add_history (s);
2249: execute_line (s);
2250: @}
2251:
2252: free (line);
2253: @}
2254: exit (0);
2255: @}
2256:
2257: /* Execute a command line. */
2258: int
2259: execute_line (line)
2260: char *line;
2261: @{
2262: register int i;
2263: COMMAND *command;
2264: char *word;
2265:
2266: /* Isolate the command word. */
2267: i = 0;
2268: while (line[i] && whitespace (line[i]))
2269: i++;
2270: word = line + i;
2271:
2272: while (line[i] && !whitespace (line[i]))
2273: i++;
2274:
2275: if (line[i])
2276: line[i++] = '\0';
2277:
2278: command = find_command (word);
2279:
2280: if (!command)
2281: @{
2282: fprintf (stderr, "%s: No such command for FileMan.\n", word);
2283: return (-1);
2284: @}
2285:
2286: /* Get argument to command, if any. */
2287: while (whitespace (line[i]))
2288: i++;
2289:
2290: word = line + i;
2291:
2292: /* Call the function. */
2293: return ((*(command->func)) (word));
2294: @}
2295:
2296: /* Look up NAME as the name of a command, and return a pointer to that
2297: command. Return a NULL pointer if NAME isn't a command name. */
2298: COMMAND *
2299: find_command (name)
2300: char *name;
2301: @{
2302: register int i;
2303:
2304: for (i = 0; commands[i].name; i++)
2305: if (strcmp (name, commands[i].name) == 0)
2306: return (&commands[i]);
2307:
2308: return ((COMMAND *)NULL);
2309: @}
2310:
2311: /* Strip whitespace from the start and end of STRING. Return a pointer
2312: into STRING. */
2313: char *
2314: stripwhite (string)
2315: char *string;
2316: @{
2317: register char *s, *t;
2318:
2319: for (s = string; whitespace (*s); s++)
2320: ;
2321:
2322: if (*s == 0)
2323: return (s);
2324:
2325: t = s + strlen (s) - 1;
2326: while (t > s && whitespace (*t))
2327: t--;
2328: *++t = '\0';
2329:
2330: return s;
2331: @}
2332:
2333: /* **************************************************************** */
2334: /* */
2335: /* Interface to Readline Completion */
2336: /* */
2337: /* **************************************************************** */
2338:
2339: char *command_generator PARAMS((const char *, int));
2340: char **fileman_completion PARAMS((const char *, int, int));
2341:
2342: /* Tell the GNU Readline library how to complete. We want to try to complete
2343: on command names if this is the first word in the line, or on filenames
2344: if not. */
2345: initialize_readline ()
2346: @{
2347: /* Allow conditional parsing of the ~/.inputrc file. */
2348: rl_readline_name = "FileMan";
2349:
2350: /* Tell the completer that we want a crack first. */
2351: rl_attempted_completion_function = fileman_completion;
2352: @}
2353:
2354: /* Attempt to complete on the contents of TEXT. START and END bound the
2355: region of rl_line_buffer that contains the word to complete. TEXT is
2356: the word to complete. We can use the entire contents of rl_line_buffer
2357: in case we want to do some simple parsing. Return the array of matches,
2358: or NULL if there aren't any. */
2359: char **
2360: fileman_completion (text, start, end)
2361: const char *text;
2362: int start, end;
2363: @{
2364: char **matches;
2365:
2366: matches = (char **)NULL;
2367:
2368: /* If this word is at the start of the line, then it is a command
2369: to complete. Otherwise it is the name of a file in the current
2370: directory. */
2371: if (start == 0)
2372: matches = rl_completion_matches (text, command_generator);
2373:
2374: return (matches);
2375: @}
2376:
2377: /* Generator function for command completion. STATE lets us know whether
2378: to start from scratch; without any state (i.e. STATE == 0), then we
2379: start at the top of the list. */
2380: char *
2381: command_generator (text, state)
2382: const char *text;
2383: int state;
2384: @{
2385: static int list_index, len;
2386: char *name;
2387:
2388: /* If this is a new word to complete, initialize now. This includes
2389: saving the length of TEXT for efficiency, and initializing the index
2390: variable to 0. */
2391: if (!state)
2392: @{
2393: list_index = 0;
2394: len = strlen (text);
2395: @}
2396:
2397: /* Return the next name which partially matches from the command list. */
2398: while (name = commands[list_index].name)
2399: @{
2400: list_index++;
2401:
2402: if (strncmp (name, text, len) == 0)
2403: return (dupstr(name));
2404: @}
2405:
2406: /* If no names matched, then return NULL. */
2407: return ((char *)NULL);
2408: @}
2409:
2410: /* **************************************************************** */
2411: /* */
2412: /* FileMan Commands */
2413: /* */
2414: /* **************************************************************** */
2415:
2416: /* String to pass to system (). This is for the LIST, VIEW and RENAME
2417: commands. */
2418: static char syscom[1024];
2419:
2420: /* List the file(s) named in arg. */
2421: com_list (arg)
2422: char *arg;
2423: @{
2424: if (!arg)
2425: arg = "";
2426:
2427: sprintf (syscom, "ls -FClg %s", arg);
2428: return (system (syscom));
2429: @}
2430:
2431: com_view (arg)
2432: char *arg;
2433: @{
2434: if (!valid_argument ("view", arg))
2435: return 1;
2436:
2437: #if defined (__MSDOS__)
2438: /* more.com doesn't grok slashes in pathnames */
2439: sprintf (syscom, "less %s", arg);
2440: #else
2441: sprintf (syscom, "more %s", arg);
2442: #endif
2443: return (system (syscom));
2444: @}
2445:
2446: com_rename (arg)
2447: char *arg;
2448: @{
2449: too_dangerous ("rename");
2450: return (1);
2451: @}
2452:
2453: com_stat (arg)
2454: char *arg;
2455: @{
2456: struct stat finfo;
2457:
2458: if (!valid_argument ("stat", arg))
2459: return (1);
2460:
2461: if (stat (arg, &finfo) == -1)
2462: @{
2463: perror (arg);
2464: return (1);
2465: @}
2466:
2467: printf ("Statistics for `%s':\n", arg);
2468:
2469: printf ("%s has %d link%s, and is %d byte%s in length.\n",
2470: arg,
2471: finfo.st_nlink,
2472: (finfo.st_nlink == 1) ? "" : "s",
2473: finfo.st_size,
2474: (finfo.st_size == 1) ? "" : "s");
2475: printf ("Inode Last Change at: %s", ctime (&finfo.st_ctime));
2476: printf (" Last access at: %s", ctime (&finfo.st_atime));
2477: printf (" Last modified at: %s", ctime (&finfo.st_mtime));
2478: return (0);
2479: @}
2480:
2481: com_delete (arg)
2482: char *arg;
2483: @{
2484: too_dangerous ("delete");
2485: return (1);
2486: @}
2487:
2488: /* Print out help for ARG, or for all of the commands if ARG is
2489: not present. */
2490: com_help (arg)
2491: char *arg;
2492: @{
2493: register int i;
2494: int printed = 0;
2495:
2496: for (i = 0; commands[i].name; i++)
2497: @{
2498: if (!*arg || (strcmp (arg, commands[i].name) == 0))
2499: @{
2500: printf ("%s\t\t%s.\n", commands[i].name, commands[i].doc);
2501: printed++;
2502: @}
2503: @}
2504:
2505: if (!printed)
2506: @{
2507: printf ("No commands match `%s'. Possibilties are:\n", arg);
2508:
2509: for (i = 0; commands[i].name; i++)
2510: @{
2511: /* Print in six columns. */
2512: if (printed == 6)
2513: @{
2514: printed = 0;
2515: printf ("\n");
2516: @}
2517:
2518: printf ("%s\t", commands[i].name);
2519: printed++;
2520: @}
2521:
2522: if (printed)
2523: printf ("\n");
2524: @}
2525: return (0);
2526: @}
2527:
2528: /* Change to the directory ARG. */
2529: com_cd (arg)
2530: char *arg;
2531: @{
2532: if (chdir (arg) == -1)
2533: @{
2534: perror (arg);
2535: return 1;
2536: @}
2537:
2538: com_pwd ("");
2539: return (0);
2540: @}
2541:
2542: /* Print out the current working directory. */
2543: com_pwd (ignore)
2544: char *ignore;
2545: @{
2546: char dir[1024], *s;
2547:
2548: s = getcwd (dir, sizeof(dir) - 1);
2549: if (s == 0)
2550: @{
2551: printf ("Error getting pwd: %s\n", dir);
2552: return 1;
2553: @}
2554:
2555: printf ("Current directory is %s\n", dir);
2556: return 0;
2557: @}
2558:
2559: /* The user wishes to quit using this program. Just set DONE non-zero. */
2560: com_quit (arg)
2561: char *arg;
2562: @{
2563: done = 1;
2564: return (0);
2565: @}
2566:
2567: /* Function which tells you that you can't do this. */
2568: too_dangerous (caller)
2569: char *caller;
2570: @{
2571: fprintf (stderr,
2572: "%s: Too dangerous for me to distribute. Write it yourself.\n",
2573: caller);
2574: @}
2575:
2576: /* Return non-zero if ARG is a valid argument for CALLER, else print
2577: an error message and return zero. */
2578: int
2579: valid_argument (caller, arg)
2580: char *caller, *arg;
2581: @{
2582: if (!arg || !*arg)
2583: @{
2584: fprintf (stderr, "%s: Argument required.\n", caller);
2585: return (0);
2586: @}
2587:
2588: return (1);
2589: @}
2590: @end smallexample
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