xref: /openbmc/qemu/util/readline.c (revision 4fe6d78b)
1 /*
2  * QEMU readline utility
3  *
4  * Copyright (c) 2003-2004 Fabrice Bellard
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a copy
7  * of this software and associated documentation files (the "Software"), to deal
8  * in the Software without restriction, including without limitation the rights
9  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
10  * copies of the Software, and to permit persons to whom the Software is
11  * furnished to do so, subject to the following conditions:
12  *
13  * The above copyright notice and this permission notice shall be included in
14  * all copies or substantial portions of the Software.
15  *
16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
19  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
22  * THE SOFTWARE.
23  */
24 
25 #include "qemu/osdep.h"
26 #include "qemu-common.h"
27 #include "qemu/readline.h"
28 #include "qemu/cutils.h"
29 
30 #define IS_NORM 0
31 #define IS_ESC  1
32 #define IS_CSI  2
33 #define IS_SS3  3
34 
35 void readline_show_prompt(ReadLineState *rs)
36 {
37     rs->printf_func(rs->opaque, "%s", rs->prompt);
38     rs->flush_func(rs->opaque);
39     rs->last_cmd_buf_index = 0;
40     rs->last_cmd_buf_size = 0;
41     rs->esc_state = IS_NORM;
42 }
43 
44 /* update the displayed command line */
45 static void readline_update(ReadLineState *rs)
46 {
47     int i, delta, len;
48 
49     if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
50         memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
51         for(i = 0; i < rs->last_cmd_buf_index; i++) {
52             rs->printf_func(rs->opaque, "\033[D");
53         }
54         rs->cmd_buf[rs->cmd_buf_size] = '\0';
55         if (rs->read_password) {
56             len = strlen(rs->cmd_buf);
57             for(i = 0; i < len; i++)
58                 rs->printf_func(rs->opaque, "*");
59         } else {
60             rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
61         }
62         rs->printf_func(rs->opaque, "\033[K");
63         memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
64         rs->last_cmd_buf_size = rs->cmd_buf_size;
65         rs->last_cmd_buf_index = rs->cmd_buf_size;
66     }
67     if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
68         delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
69         if (delta > 0) {
70             for(i = 0;i < delta; i++) {
71                 rs->printf_func(rs->opaque, "\033[C");
72             }
73         } else {
74             delta = -delta;
75             for(i = 0;i < delta; i++) {
76                 rs->printf_func(rs->opaque, "\033[D");
77             }
78         }
79         rs->last_cmd_buf_index = rs->cmd_buf_index;
80     }
81     rs->flush_func(rs->opaque);
82 }
83 
84 static void readline_insert_char(ReadLineState *rs, int ch)
85 {
86     if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
87         memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
88                 rs->cmd_buf + rs->cmd_buf_index,
89                 rs->cmd_buf_size - rs->cmd_buf_index);
90         rs->cmd_buf[rs->cmd_buf_index] = ch;
91         rs->cmd_buf_size++;
92         rs->cmd_buf_index++;
93     }
94 }
95 
96 static void readline_backward_char(ReadLineState *rs)
97 {
98     if (rs->cmd_buf_index > 0) {
99         rs->cmd_buf_index--;
100     }
101 }
102 
103 static void readline_forward_char(ReadLineState *rs)
104 {
105     if (rs->cmd_buf_index < rs->cmd_buf_size) {
106         rs->cmd_buf_index++;
107     }
108 }
109 
110 static void readline_delete_char(ReadLineState *rs)
111 {
112     if (rs->cmd_buf_index < rs->cmd_buf_size) {
113         memmove(rs->cmd_buf + rs->cmd_buf_index,
114                 rs->cmd_buf + rs->cmd_buf_index + 1,
115                 rs->cmd_buf_size - rs->cmd_buf_index - 1);
116         rs->cmd_buf_size--;
117     }
118 }
119 
120 static void readline_backspace(ReadLineState *rs)
121 {
122     if (rs->cmd_buf_index > 0) {
123         readline_backward_char(rs);
124         readline_delete_char(rs);
125     }
126 }
127 
128 static void readline_backword(ReadLineState *rs)
129 {
130     int start;
131 
132     if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
133         return;
134     }
135 
136     start = rs->cmd_buf_index - 1;
137 
138     /* find first word (backwards) */
139     while (start > 0) {
140         if (!qemu_isspace(rs->cmd_buf[start])) {
141             break;
142         }
143 
144         --start;
145     }
146 
147     /* find first space (backwards) */
148     while (start > 0) {
149         if (qemu_isspace(rs->cmd_buf[start])) {
150             ++start;
151             break;
152         }
153 
154         --start;
155     }
156 
157     /* remove word */
158     if (start < rs->cmd_buf_index) {
159         memmove(rs->cmd_buf + start,
160                 rs->cmd_buf + rs->cmd_buf_index,
161                 rs->cmd_buf_size - rs->cmd_buf_index);
162         rs->cmd_buf_size -= rs->cmd_buf_index - start;
163         rs->cmd_buf_index = start;
164     }
165 }
166 
167 static void readline_bol(ReadLineState *rs)
168 {
169     rs->cmd_buf_index = 0;
170 }
171 
172 static void readline_eol(ReadLineState *rs)
173 {
174     rs->cmd_buf_index = rs->cmd_buf_size;
175 }
176 
177 static void readline_up_char(ReadLineState *rs)
178 {
179     int idx;
180 
181     if (rs->hist_entry == 0)
182 	return;
183     if (rs->hist_entry == -1) {
184 	/* Find latest entry */
185 	for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
186 	    if (rs->history[idx] == NULL)
187 		break;
188 	}
189 	rs->hist_entry = idx;
190     }
191     rs->hist_entry--;
192     if (rs->hist_entry >= 0) {
193 	pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
194                 rs->history[rs->hist_entry]);
195 	rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
196     }
197 }
198 
199 static void readline_down_char(ReadLineState *rs)
200 {
201     if (rs->hist_entry == -1)
202         return;
203     if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
204         rs->history[++rs->hist_entry] != NULL) {
205 	pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
206                 rs->history[rs->hist_entry]);
207     } else {
208         rs->cmd_buf[0] = 0;
209 	rs->hist_entry = -1;
210     }
211     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
212 }
213 
214 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
215 {
216     char *hist_entry, *new_entry;
217     int idx;
218 
219     if (cmdline[0] == '\0')
220 	return;
221     new_entry = NULL;
222     if (rs->hist_entry != -1) {
223 	/* We were editing an existing history entry: replace it */
224 	hist_entry = rs->history[rs->hist_entry];
225 	idx = rs->hist_entry;
226 	if (strcmp(hist_entry, cmdline) == 0) {
227 	    goto same_entry;
228 	}
229     }
230     /* Search cmdline in history buffers */
231     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
232 	hist_entry = rs->history[idx];
233 	if (hist_entry == NULL)
234 	    break;
235 	if (strcmp(hist_entry, cmdline) == 0) {
236 	same_entry:
237 	    new_entry = hist_entry;
238 	    /* Put this entry at the end of history */
239 	    memmove(&rs->history[idx], &rs->history[idx + 1],
240 		    (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
241 	    rs->history[READLINE_MAX_CMDS - 1] = NULL;
242 	    for (; idx < READLINE_MAX_CMDS; idx++) {
243 		if (rs->history[idx] == NULL)
244 		    break;
245 	    }
246 	    break;
247 	}
248     }
249     if (idx == READLINE_MAX_CMDS) {
250 	/* Need to get one free slot */
251         g_free(rs->history[0]);
252 	memmove(rs->history, &rs->history[1],
253 	        (READLINE_MAX_CMDS - 1) * sizeof(char *));
254 	rs->history[READLINE_MAX_CMDS - 1] = NULL;
255 	idx = READLINE_MAX_CMDS - 1;
256     }
257     if (new_entry == NULL)
258         new_entry = g_strdup(cmdline);
259     rs->history[idx] = new_entry;
260     rs->hist_entry = -1;
261 }
262 
263 /* completion support */
264 
265 void readline_add_completion(ReadLineState *rs, const char *str)
266 {
267     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
268         int i;
269         for (i = 0; i < rs->nb_completions; i++) {
270             if (!strcmp(rs->completions[i], str)) {
271                 return;
272             }
273         }
274         rs->completions[rs->nb_completions++] = g_strdup(str);
275     }
276 }
277 
278 void readline_set_completion_index(ReadLineState *rs, int index)
279 {
280     rs->completion_index = index;
281 }
282 
283 static int completion_comp(const void *a, const void *b)
284 {
285     return strcmp(*(const char **) a, *(const char **) b);
286 }
287 
288 static void readline_completion(ReadLineState *rs)
289 {
290     int len, i, j, max_width, nb_cols, max_prefix;
291     char *cmdline;
292 
293     rs->nb_completions = 0;
294 
295     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
296     rs->completion_finder(rs->opaque, cmdline);
297     g_free(cmdline);
298 
299     /* no completion found */
300     if (rs->nb_completions <= 0)
301         return;
302     if (rs->nb_completions == 1) {
303         len = strlen(rs->completions[0]);
304         for(i = rs->completion_index; i < len; i++) {
305             readline_insert_char(rs, rs->completions[0][i]);
306         }
307         /* extra space for next argument. XXX: make it more generic */
308         if (len > 0 && rs->completions[0][len - 1] != '/')
309             readline_insert_char(rs, ' ');
310     } else {
311         qsort(rs->completions, rs->nb_completions, sizeof(char *),
312               completion_comp);
313         rs->printf_func(rs->opaque, "\n");
314         max_width = 0;
315         max_prefix = 0;
316         for(i = 0; i < rs->nb_completions; i++) {
317             len = strlen(rs->completions[i]);
318             if (i==0) {
319                 max_prefix = len;
320             } else {
321                 if (len < max_prefix)
322                     max_prefix = len;
323                 for(j=0; j<max_prefix; j++) {
324                     if (rs->completions[i][j] != rs->completions[0][j])
325                         max_prefix = j;
326                 }
327             }
328             if (len > max_width)
329                 max_width = len;
330         }
331         if (max_prefix > 0)
332             for(i = rs->completion_index; i < max_prefix; i++) {
333                 readline_insert_char(rs, rs->completions[0][i]);
334             }
335         max_width += 2;
336         if (max_width < 10)
337             max_width = 10;
338         else if (max_width > 80)
339             max_width = 80;
340         nb_cols = 80 / max_width;
341         j = 0;
342         for(i = 0; i < rs->nb_completions; i++) {
343             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
344             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
345                 rs->printf_func(rs->opaque, "\n");
346                 j = 0;
347             }
348         }
349         readline_show_prompt(rs);
350     }
351     for (i = 0; i < rs->nb_completions; i++) {
352         g_free(rs->completions[i]);
353     }
354 }
355 
356 static void readline_clear_screen(ReadLineState *rs)
357 {
358     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
359     readline_show_prompt(rs);
360 }
361 
362 /* return true if command handled */
363 void readline_handle_byte(ReadLineState *rs, int ch)
364 {
365     switch(rs->esc_state) {
366     case IS_NORM:
367         switch(ch) {
368         case 1:
369             readline_bol(rs);
370             break;
371         case 4:
372             readline_delete_char(rs);
373             break;
374         case 5:
375             readline_eol(rs);
376             break;
377         case 9:
378             readline_completion(rs);
379             break;
380         case 12:
381             readline_clear_screen(rs);
382             break;
383         case 10:
384         case 13:
385             rs->cmd_buf[rs->cmd_buf_size] = '\0';
386             if (!rs->read_password)
387                 readline_hist_add(rs, rs->cmd_buf);
388             rs->printf_func(rs->opaque, "\n");
389             rs->cmd_buf_index = 0;
390             rs->cmd_buf_size = 0;
391             rs->last_cmd_buf_index = 0;
392             rs->last_cmd_buf_size = 0;
393             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
394             break;
395         case 23:
396             /* ^W */
397             readline_backword(rs);
398             break;
399         case 27:
400             rs->esc_state = IS_ESC;
401             break;
402         case 127:
403         case 8:
404             readline_backspace(rs);
405             break;
406 	case 155:
407             rs->esc_state = IS_CSI;
408 	    break;
409         default:
410             if (ch >= 32) {
411                 readline_insert_char(rs, ch);
412             }
413             break;
414         }
415         break;
416     case IS_ESC:
417         if (ch == '[') {
418             rs->esc_state = IS_CSI;
419             rs->esc_param = 0;
420         } else if (ch == 'O') {
421             rs->esc_state = IS_SS3;
422             rs->esc_param = 0;
423         } else {
424             rs->esc_state = IS_NORM;
425         }
426         break;
427     case IS_CSI:
428         switch(ch) {
429 	case 'A':
430 	case 'F':
431 	    readline_up_char(rs);
432 	    break;
433 	case 'B':
434 	case 'E':
435 	    readline_down_char(rs);
436 	    break;
437         case 'D':
438             readline_backward_char(rs);
439             break;
440         case 'C':
441             readline_forward_char(rs);
442             break;
443         case '0' ... '9':
444             rs->esc_param = rs->esc_param * 10 + (ch - '0');
445             goto the_end;
446         case '~':
447             switch(rs->esc_param) {
448             case 1:
449                 readline_bol(rs);
450                 break;
451             case 3:
452                 readline_delete_char(rs);
453                 break;
454             case 4:
455                 readline_eol(rs);
456                 break;
457             }
458             break;
459         default:
460             break;
461         }
462         rs->esc_state = IS_NORM;
463     the_end:
464         break;
465     case IS_SS3:
466         switch(ch) {
467         case 'F':
468             readline_eol(rs);
469             break;
470         case 'H':
471             readline_bol(rs);
472             break;
473         }
474         rs->esc_state = IS_NORM;
475         break;
476     }
477     readline_update(rs);
478 }
479 
480 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
481                     ReadLineFunc *readline_func, void *opaque)
482 {
483     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
484     rs->readline_func = readline_func;
485     rs->readline_opaque = opaque;
486     rs->read_password = read_password;
487     readline_restart(rs);
488 }
489 
490 void readline_restart(ReadLineState *rs)
491 {
492     rs->cmd_buf_index = 0;
493     rs->cmd_buf_size = 0;
494 }
495 
496 const char *readline_get_history(ReadLineState *rs, unsigned int index)
497 {
498     if (index >= READLINE_MAX_CMDS)
499         return NULL;
500     return rs->history[index];
501 }
502 
503 void readline_free(ReadLineState *rs)
504 {
505     int i;
506 
507     if (!rs) {
508         return;
509     }
510     for (i = 0; i < READLINE_MAX_CMDS; i++) {
511         g_free(rs->history[i]);
512     }
513     for (i = 0; i < READLINE_MAX_COMPLETIONS; i++) {
514         g_free(rs->completions[i]);
515     }
516     g_free(rs);
517 }
518 
519 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
520                              ReadLineFlushFunc *flush_func,
521                              void *opaque,
522                              ReadLineCompletionFunc *completion_finder)
523 {
524     ReadLineState *rs = g_new0(ReadLineState, 1);
525 
526     rs->hist_entry = -1;
527     rs->opaque = opaque;
528     rs->printf_func = printf_func;
529     rs->flush_func = flush_func;
530     rs->completion_finder = completion_finder;
531 
532     return rs;
533 }
534