interactive: Fix wipe_bottom_line() on MacOS.
[paraslash.git] / interactive.c
1 /*
2 * Copyright (C) 2011-2012 Andre Noll <maan@systemlinux.org>
3 *
4 * Licensed under the GPL v2. For licencing details see COPYING.
5 */
6
7 /** \file interactive.c Readline abstraction for interactive sessions. */
8
9 #include <regex.h>
10 #include <stdbool.h>
11 #include <curses.h>
12 #include <readline/readline.h>
13 #include <readline/history.h>
14 #include <sys/ioctl.h>
15 #include <assert.h>
16 #include <signal.h>
17
18 #include "para.h"
19 #include "fd.h"
20 #include "buffer_tree.h"
21 #include "list.h"
22 #include "sched.h"
23 #include "interactive.h"
24 #include "string.h"
25 #include "error.h"
26
27 struct i9e_private {
28 struct i9e_client_info *ici;
29 FILE *stderr_stream;
30 int num_columns;
31 char empty_line[1000];
32 struct task task;
33 struct btr_node *stdout_btrn;
34 bool line_handler_running;
35 bool input_eof;
36 bool caught_sigint;
37 bool caught_sigterm;
38 };
39 static struct i9e_private i9e_private, *i9ep = &i9e_private;
40
41 static bool is_prefix(const char *partial, const char *full, size_t len)
42 {
43 if (len == 0)
44 len = strlen(partial);
45 return !strncmp(partial, full, len);
46 }
47
48 /*
49 * Generator function for command completion. STATE lets us know whether
50 * to start from scratch; without any state (i.e. STATE == 0), then we
51 * start at the top of the list.
52 */
53 static char *command_generator(const char *text, int state)
54 {
55 static int list_index, len;
56 const char *name;
57 struct i9e_client_info *ici = i9ep->ici;
58
59 rl_attempted_completion_over = 1; /* disable filename completion */
60 /*
61 * If this is a new word to complete, initialize now. This includes
62 * saving the length of TEXT for efficiency, and initializing the index
63 * variable to 0.
64 */
65 if (state == 0) {
66 list_index = 0;
67 len = strlen(text);
68 }
69 /* Return the next name which partially matches from the command list. */
70 while ((name = ici->completers[list_index].name)) {
71 list_index++;
72 if (is_prefix(text, name, len))
73 return para_strdup(name);
74 }
75 return NULL; /* no names matched */
76 }
77
78 static void reset_completion_result(struct i9e_completion_result *cr)
79 {
80 cr->dont_append_space = false;
81 cr->filename_completion_desired = false;
82 cr->matches = NULL;
83 }
84
85 static void create_matches(struct i9e_completion_info *ci,
86 struct i9e_completer *completers,
87 struct i9e_completion_result *cr)
88 {
89 int i, ret;
90
91 reset_completion_result(cr);
92
93 ret = create_argv(ci->buffer, " ", &ci->argv);
94 if (ret < 0 || !ci->argv[0])
95 return;
96
97 ci->argc = ret;
98 ci->word_num = compute_word_num(ci->buffer, " ", ci->point);
99 for (i = 0; completers[i].name; i++) {
100 if (strcmp(completers[i].name, ci->argv[0]) != 0)
101 continue;
102 completers[i].completer(ci, cr);
103 break;
104 }
105 PARA_DEBUG_LOG("current word: %d (%s)\n", ci->word_num,
106 ci->argv[ci->word_num]);
107 if (cr->matches)
108 for (i = 0; cr->matches[i]; i++)
109 PARA_DEBUG_LOG("match %d: %s\n", i, cr->matches[i]);
110 }
111
112 static char *completion_generator(const char *word, int state)
113 {
114 static int list_index;
115 static char **argv, **matches;
116 struct i9e_completer *completers = i9ep->ici->completers;
117 struct i9e_completion_info ci = {
118 .word = (char *)word,
119 .point = rl_point,
120 .buffer = rl_line_buffer,
121 };
122 struct i9e_completion_result cr = {.matches = NULL};
123
124 if (state != 0)
125 goto out;
126 /* clean up previous matches and set defaults */
127 free(matches);
128 matches = NULL;
129 free_argv(argv);
130 argv = NULL;
131 list_index = 0;
132 rl_completion_append_character = ' ';
133 rl_completion_suppress_append = false;
134 rl_attempted_completion_over = true;
135
136 create_matches(&ci, completers, &cr);
137
138 matches = cr.matches;
139 argv = ci.argv;
140 rl_completion_suppress_append = cr.dont_append_space;
141 rl_attempted_completion_over = !cr.filename_completion_desired;
142 out:
143 if (!matches)
144 return NULL;
145 return matches[list_index++];
146 }
147
148 /*
149 * Attempt to complete on the contents of TEXT. START and END bound the
150 * region of rl_line_buffer that contains the word to complete. TEXT is
151 * the word to complete. We can use the entire contents of rl_line_buffer
152 * in case we want to do some simple parsing. Return the array of matches,
153 * or NULL if there aren't any.
154 */
155 static char **i9e_completer(const char *text, int start, __a_unused int end)
156 {
157 struct i9e_client_info *ici = i9ep->ici;
158
159 if (!ici->completers)
160 return NULL;
161 /* Complete on command names if this is the first word in the line. */
162 if (start == 0)
163 return rl_completion_matches(text, command_generator);
164 return rl_completion_matches(text, completion_generator);
165 }
166
167 /**
168 * Prepare writing to stdout.
169 *
170 * \param producer The buffer tree node which produces output.
171 *
172 * The i9e subsystem maintains a buffer tree node which may be attached to
173 * another node which generates output (a "producer"). When attached, the i9e
174 * buffer tree node copies the buffers generated by the producer to stdout.
175 *
176 * This function attaches the i9e input queue to an output queue of \a
177 * producer.
178 *
179 * \return Standard.
180 */
181 void i9e_attach_to_stdout(struct btr_node *producer)
182 {
183 btr_remove_node(&i9ep->stdout_btrn);
184 i9ep->stdout_btrn = btr_new_node(&(struct btr_node_description)
185 EMBRACE(.name = "interactive_stdout", .parent = producer));
186 }
187
188 static void wipe_bottom_line(void)
189 {
190 char x[] = " ";
191 int n = i9ep->num_columns;
192
193 /*
194 * For reasons beyond my understanding, writing more than 68 characters
195 * here causes MacOS to mess up the terminal. Writing a line of spaces
196 * in smaller chunks works fine though. Weird.
197 */
198 fprintf(i9ep->stderr_stream, "\r");
199 while (n > 0) {
200 if (n >= sizeof(x)) {
201 fprintf(i9ep->stderr_stream, "%s", x);
202 n -= sizeof(x);
203 continue;
204 }
205 x[n] = '\0';
206 fprintf(i9ep->stderr_stream, "%s", x);
207 break;
208 }
209 fprintf(i9ep->stderr_stream, "\r");
210 }
211
212 /**
213 * Reset the terminal and save the in-memory command line history.
214 *
215 * This should be called before the caller exits.
216 */
217 void i9e_close(void)
218 {
219 char *hf = i9ep->ici->history_file;
220
221 rl_deprep_terminal();
222 if (hf)
223 write_history(hf);
224 wipe_bottom_line();
225 }
226
227 static void clear_bottom_line(void)
228 {
229 int point;
230 char *text;
231
232 if (rl_point == 0 && rl_end == 0)
233 return wipe_bottom_line();
234 /*
235 * We might have a multi-line input that needs to be wiped here, so the
236 * simple printf("\r<space>\r") is insufficient. To workaround this, we
237 * remove the whole line, redisplay and restore the killed text.
238 */
239 point = rl_point;
240 text = rl_copy_text(0, rl_end);
241 rl_kill_full_line(0, 0);
242 rl_redisplay();
243 wipe_bottom_line(); /* wipe out the prompt */
244 rl_insert_text(text);
245 rl_point = point;
246 }
247
248 static bool input_available(void)
249 {
250 fd_set rfds;
251 struct timeval tv = {0, 0};
252 int ret;
253
254 FD_ZERO(&rfds);
255 FD_SET(i9ep->ici->fds[0], &rfds);
256 ret = para_select(1, &rfds, NULL, &tv);
257 return ret > 0;
258 }
259
260 static void i9e_line_handler(char *line)
261 {
262 int ret;
263
264 ret = i9ep->ici->line_handler(line);
265 if (ret < 0)
266 PARA_WARNING_LOG("%s\n", para_strerror(-ret));
267 rl_set_prompt("");
268 if (line) {
269 if (!*line)
270 rl_set_prompt(i9ep->ici->prompt);
271 else
272 add_history(line);
273 free(line);
274 } else {
275 rl_set_prompt("");
276 i9ep->input_eof = true;
277 }
278 }
279
280 static void i9e_input(void)
281 {
282 do {
283 rl_callback_read_char();
284 } while (input_available());
285 }
286
287 static void i9e_post_select(struct sched *s, struct task *t)
288 {
289 int ret;
290 struct btr_node *btrn = i9ep->stdout_btrn;
291 struct i9e_client_info *ici = i9ep->ici;
292 char *buf;
293 size_t sz;
294
295 ret = -E_I9E_EOF;
296 if (i9ep->input_eof)
297 goto rm_btrn;
298 ret = -E_I9E_TERM_RQ;
299 if (i9ep->caught_sigterm)
300 goto rm_btrn;
301 if (!btrn) {
302 i9ep->caught_sigint = false;
303 if (FD_ISSET(ici->fds[0], &s->rfds))
304 i9e_input();
305 return;
306 }
307 ret = 0;
308 if (i9ep->caught_sigint)
309 goto rm_btrn;
310 ret = btr_node_status(i9ep->stdout_btrn, 0, BTR_NT_LEAF);
311 if (ret < 0)
312 goto rm_btrn;
313 sz = btr_next_buffer(btrn, &buf);
314 if (sz == 0)
315 goto out;
316 ret = xwrite(ici->fds[1], buf, sz);
317 if (ret < 0)
318 goto rm_btrn;
319 btr_consume(btrn, ret);
320 goto out;
321 rm_btrn:
322 btr_remove_node(&i9ep->stdout_btrn);
323 rl_set_prompt(i9ep->ici->prompt);
324 rl_redisplay();
325 out:
326 t->error = 0;
327 }
328
329 static void i9e_pre_select(struct sched *s, __a_unused struct task *t)
330 {
331 int ret;
332
333 if (i9ep->input_eof || i9ep->caught_sigint || i9ep->caught_sigterm) {
334 sched_min_delay(s);
335 return;
336 }
337 if (i9ep->stdout_btrn) {
338 ret = btr_node_status(i9ep->stdout_btrn, 0, BTR_NT_LEAF);
339 if (ret < 0) {
340 sched_min_delay(s);
341 return;
342 }
343 if (ret > 0)
344 para_fd_set(i9ep->ici->fds[1], &s->wfds, &s->max_fileno);
345 }
346 /*
347 * fd[0] might have been reset to blocking mode if our job was moved to
348 * the background due to CTRL-Z or SIGSTOP, so set the fd back to
349 * nonblocking mode.
350 */
351 ret = mark_fd_nonblocking(i9ep->ici->fds[0]);
352 if (ret < 0)
353 PARA_WARNING_LOG("set to nonblock failed: (fd0 %d, %s)\n",
354 i9ep->ici->fds[0], para_strerror(-ret));
355 para_fd_set(i9ep->ici->fds[0], &s->rfds, &s->max_fileno);
356 }
357
358 static void update_winsize(void)
359 {
360 struct winsize w;
361 int ret = ioctl(i9ep->ici->fds[2], TIOCGWINSZ, (char *)&w);
362
363 if (ret >= 0) {
364 assert(w.ws_col < sizeof(i9ep->empty_line));
365 i9ep->num_columns = w.ws_col;
366 } else
367 i9ep->num_columns = 80;
368
369 memset(i9ep->empty_line, ' ', i9ep->num_columns);
370 i9ep->empty_line[i9ep->num_columns] = '\0';
371 }
372
373 /**
374 * Register the i9e task and initialize readline.
375 *
376 * \param ici The i9e configuration parameters set by the caller.
377 * \param s The scheduler instance to add the i9e task to.
378 *
379 * The caller must allocate and initialize the structure \a ici points to.
380 *
381 * \return Standard.
382 * \sa \ref register_task().
383 */
384 int i9e_open(struct i9e_client_info *ici, struct sched *s)
385 {
386 int ret;
387
388 if (!isatty(ici->fds[0]))
389 return -E_I9E_SETUPTERM;
390 ret = mark_fd_nonblocking(ici->fds[0]);
391 if (ret < 0)
392 return ret;
393 ret = mark_fd_nonblocking(ici->fds[1]);
394 if (ret < 0)
395 return ret;
396 i9ep->task.pre_select = i9e_pre_select;
397 i9ep->task.post_select = i9e_post_select;
398 sprintf(i9ep->task.status, "i9e");
399 register_task(s, &i9ep->task);
400 rl_readline_name = "para_i9e";
401 rl_basic_word_break_characters = " ";
402 rl_attempted_completion_function = i9e_completer;
403 i9ep->ici = ici;
404 i9ep->stderr_stream = fdopen(ici->fds[2], "w");
405 setvbuf(i9ep->stderr_stream, NULL, _IONBF, 0);
406
407 if (ici->history_file)
408 read_history(ici->history_file);
409 update_winsize();
410 rl_callback_handler_install(i9ep->ici->prompt, i9e_line_handler);
411 return 1;
412 }
413
414 static void reset_line_state(void)
415 {
416 if (i9ep->stdout_btrn)
417 return;
418 rl_on_new_line();
419 rl_reset_line_state();
420 rl_forced_update_display();
421 }
422
423 /**
424 * The log function of the i9e subsystem.
425 *
426 * \param ll Severity log level.
427 * \param fmt Printf-like format string.
428 *
429 * This clears the bottom line of the terminal if necessary and writes the
430 * string given by \a fmt to fd[2], where fd[] is the array provided earlier in
431 * \ref i9e_open().
432 */
433 __printf_2_3 void i9e_log(int ll, const char* fmt,...)
434 {
435 va_list argp;
436
437 if (ll < i9ep->ici->loglevel)
438 return;
439 clear_bottom_line();
440 va_start(argp, fmt);
441 vfprintf(i9ep->stderr_stream, fmt, argp);
442 va_end(argp);
443 reset_line_state();
444 }
445
446 /**
447 * Tell i9e that the caller received a signal.
448 *
449 * \param sig_num The number of the signal received.
450 *
451 * Currently the function only cares about \p SIGINT, but this may change.
452 */
453 void i9e_signal_dispatch(int sig_num)
454 {
455 if (sig_num == SIGWINCH)
456 return update_winsize();
457 if (sig_num == SIGINT) {
458 fprintf(i9ep->stderr_stream, "\n");
459 rl_replace_line ("", false /* clear_undo */);
460 reset_line_state();
461 i9ep->caught_sigint = true;
462 }
463 if (sig_num == SIGTERM)
464 i9ep->caught_sigterm = true;
465 }
466
467 /**
468 * Wrapper for select(2) which does not restart on interrupts.
469 *
470 * \param n \sa \ref para_select().
471 * \param readfds \sa \ref para_select().
472 * \param writefds \sa \ref para_select().
473 * \param timeout_tv \sa \ref para_select().
474 *
475 * \return \sa \ref para_select().
476 *
477 * The only difference between this function and \ref para_select() is that
478 * \ref i9e_select() returns zero if the select call returned \p EINTR.
479 */
480 int i9e_select(int n, fd_set *readfds, fd_set *writefds,
481 struct timeval *timeout_tv)
482 {
483 int ret = select(n, readfds, writefds, NULL, timeout_tv);
484
485 if (ret < 0) {
486 if (errno == EINTR)
487 ret = 0;
488 else
489 ret = -ERRNO_TO_PARA_ERROR(errno);
490 }
491 return ret;
492 }
493
494 /**
495 * Return the possible completions for a given word.
496 *
497 * \param word The word to complete.
498 * \param string_list All possible words in this context.
499 * \param result String list is returned here.
500 *
501 * This function never fails. If no completion was found, a string list of
502 * length zero is returned. In any case, the result must be freed by the caller
503 * using \ref free_argv().
504 *
505 * This function is independent of readline and may be called before
506 * i9e_open().
507 *
508 * \return The number of possible completions.
509 */
510 int i9e_extract_completions(const char *word, char **string_list,
511 char ***result)
512 {
513 char **matches = para_malloc(sizeof(char *));
514 int match_count = 0, matches_len = 1;
515 char **p;
516 int len = strlen(word);
517
518 for (p = string_list; *p; p++) {
519 if (!is_prefix(word, *p, len))
520 continue;
521 match_count++;
522 if (match_count >= matches_len) {
523 matches_len *= 2;
524 matches = para_realloc(matches,
525 matches_len * sizeof(char *));
526 }
527 matches[match_count - 1] = para_strdup(*p);
528 }
529 matches[match_count] = NULL;
530 *result = matches;
531 return match_count;
532 }
533
534 /**
535 * Return the list of partially matching words.
536 *
537 * \param word The command to complete.
538 * \param completers The array containing all command names.
539 *
540 * This is similar to \ref i9e_extract_completions(), but completes on the
541 * command names in \a completers.
542 *
543 * \return See \ref i9e_extract_completions().
544 */
545 char **i9e_complete_commands(const char *word, struct i9e_completer *completers)
546 {
547 char **matches;
548 const char *cmd;
549 int i, match_count, len = strlen(word);
550
551 /*
552 * In contrast to completing against an arbitrary string list, here we
553 * know all possible completions and expect that there will not be many
554 * of them. So it should be OK to iterate twice over all commands which
555 * simplifies the code a bit.
556 */
557 for (i = 0, match_count = 0; (cmd = completers[i].name); i++) {
558 if (is_prefix(word, cmd, len))
559 match_count++;
560 }
561 matches = para_malloc((match_count + 1) * sizeof(*matches));
562 for (i = 0, match_count = 0; (cmd = completers[i].name); i++)
563 if (is_prefix(word, cmd, len))
564 matches[match_count++] = para_strdup(cmd);
565 matches[match_count] = NULL;
566 return matches;
567 }
568
569 /**
570 * Complete according to the given options.
571 *
572 * \param opts All available options.
573 * \param ci Information which was passed to the completer.
574 * \param cr Result pointer.
575 *
576 * This convenience helper can be used to complete an option. The array of all
577 * possible options is passed as the first argument. Flags, i.e. options
578 * without an argument, are expected to be listed as strings of type "-X" in \a
579 * opts while options which require an argument should be passed with a
580 * trailing "=" character like "-X=".
581 *
582 * If the word can be uniquely completed to a flag option, an additional space
583 * character is appended to the output. For non-flag options no space character
584 * is appended.
585 */
586 void i9e_complete_option(char **opts, struct i9e_completion_info *ci,
587 struct i9e_completion_result *cr)
588 {
589 int num_matches;
590
591 num_matches = i9e_extract_completions(ci->word, opts, &cr->matches);
592 if (num_matches == 1) {
593 char *opt = cr->matches[0];
594 char c = opt[strlen(opt) - 1];
595 if (c == '=')
596 cr->dont_append_space = true;
597 }
598 }
599
600 /**
601 * Print possible completions to stdout.
602 *
603 * \param completers The array of completion functions.
604 *
605 * At the end of the output a line starting with "-o=", followed by the
606 * (possibly empty) list of completion options is printed. Currently, the only
607 * two completion options are "nospace" and "filenames". The former indicates
608 * that no space should be appended even for a unique match while the latter
609 * indicates that usual filename completion should be performed in addition to
610 * the previously printed options.
611 *
612 * \return Standard.
613 */
614 int i9e_print_completions(struct i9e_completer *completers)
615 {
616 struct i9e_completion_result cr;
617 struct i9e_completion_info ci;
618 char *buf;
619 const char *end, *p;
620 int i, n, ret;
621
622 reset_completion_result(&cr);
623 buf = getenv("COMP_POINT");
624 ci.point = buf? atoi(buf) : 0;
625 ci.buffer = para_strdup(getenv("COMP_LINE"));
626
627 ci.argc = create_argv(ci.buffer, " ", &ci.argv);
628 ci.word_num = compute_word_num(ci.buffer, " ", ci.point);
629
630 end = ci.buffer + ci.point;
631 for (p = end; p > ci.buffer && *p != ' '; p--)
632 ; /* nothing */
633 if (*p == ' ')
634 p++;
635
636 n = end - p + 1;
637 ci.word = para_malloc(n + 1);
638 strncpy(ci.word, p, n);
639 ci.word[n] = '\0';
640
641 PARA_DEBUG_LOG("line: %s, point: %d (%c), wordnum: %d, word: %s\n",
642 ci.buffer, ci.point, ci.buffer[ci.point], ci.word_num, ci.word);
643 if (ci.word_num == 0)
644 cr.matches = i9e_complete_commands(ci.word, completers);
645 else
646 create_matches(&ci, completers, &cr);
647 ret = 0;
648 if (cr.matches && cr.matches[0]) {
649 for (i = 0; cr.matches[i]; i++)
650 printf("%s\n", cr.matches[i]);
651 ret = 1;
652 }
653 printf("-o=");
654 if (cr.dont_append_space)
655 printf("nospace");
656 if (cr.filename_completion_desired)
657 printf(",filenames");
658 printf("\n");
659 free_argv(cr.matches);
660 free_argv(ci.argv);
661 free(ci.buffer);
662 free(ci.word);
663 return ret;
664 }