xref: /openbmc/qemu/util/readline.c (revision da34e65c)
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 
29 #define IS_NORM 0
30 #define IS_ESC  1
31 #define IS_CSI  2
32 #define IS_SS3  3
33 
34 void readline_show_prompt(ReadLineState *rs)
35 {
36     rs->printf_func(rs->opaque, "%s", rs->prompt);
37     rs->flush_func(rs->opaque);
38     rs->last_cmd_buf_index = 0;
39     rs->last_cmd_buf_size = 0;
40     rs->esc_state = IS_NORM;
41 }
42 
43 /* update the displayed command line */
44 static void readline_update(ReadLineState *rs)
45 {
46     int i, delta, len;
47 
48     if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
49         memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
50         for(i = 0; i < rs->last_cmd_buf_index; i++) {
51             rs->printf_func(rs->opaque, "\033[D");
52         }
53         rs->cmd_buf[rs->cmd_buf_size] = '\0';
54         if (rs->read_password) {
55             len = strlen(rs->cmd_buf);
56             for(i = 0; i < len; i++)
57                 rs->printf_func(rs->opaque, "*");
58         } else {
59             rs->printf_func(rs->opaque, "%s", rs->cmd_buf);
60         }
61         rs->printf_func(rs->opaque, "\033[K");
62         memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
63         rs->last_cmd_buf_size = rs->cmd_buf_size;
64         rs->last_cmd_buf_index = rs->cmd_buf_size;
65     }
66     if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
67         delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
68         if (delta > 0) {
69             for(i = 0;i < delta; i++) {
70                 rs->printf_func(rs->opaque, "\033[C");
71             }
72         } else {
73             delta = -delta;
74             for(i = 0;i < delta; i++) {
75                 rs->printf_func(rs->opaque, "\033[D");
76             }
77         }
78         rs->last_cmd_buf_index = rs->cmd_buf_index;
79     }
80     rs->flush_func(rs->opaque);
81 }
82 
83 static void readline_insert_char(ReadLineState *rs, int ch)
84 {
85     if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
86         memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
87                 rs->cmd_buf + rs->cmd_buf_index,
88                 rs->cmd_buf_size - rs->cmd_buf_index);
89         rs->cmd_buf[rs->cmd_buf_index] = ch;
90         rs->cmd_buf_size++;
91         rs->cmd_buf_index++;
92     }
93 }
94 
95 static void readline_backward_char(ReadLineState *rs)
96 {
97     if (rs->cmd_buf_index > 0) {
98         rs->cmd_buf_index--;
99     }
100 }
101 
102 static void readline_forward_char(ReadLineState *rs)
103 {
104     if (rs->cmd_buf_index < rs->cmd_buf_size) {
105         rs->cmd_buf_index++;
106     }
107 }
108 
109 static void readline_delete_char(ReadLineState *rs)
110 {
111     if (rs->cmd_buf_index < rs->cmd_buf_size) {
112         memmove(rs->cmd_buf + rs->cmd_buf_index,
113                 rs->cmd_buf + rs->cmd_buf_index + 1,
114                 rs->cmd_buf_size - rs->cmd_buf_index - 1);
115         rs->cmd_buf_size--;
116     }
117 }
118 
119 static void readline_backspace(ReadLineState *rs)
120 {
121     if (rs->cmd_buf_index > 0) {
122         readline_backward_char(rs);
123         readline_delete_char(rs);
124     }
125 }
126 
127 static void readline_backword(ReadLineState *rs)
128 {
129     int start;
130 
131     if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
132         return;
133     }
134 
135     start = rs->cmd_buf_index - 1;
136 
137     /* find first word (backwards) */
138     while (start > 0) {
139         if (!qemu_isspace(rs->cmd_buf[start])) {
140             break;
141         }
142 
143         --start;
144     }
145 
146     /* find first space (backwards) */
147     while (start > 0) {
148         if (qemu_isspace(rs->cmd_buf[start])) {
149             ++start;
150             break;
151         }
152 
153         --start;
154     }
155 
156     /* remove word */
157     if (start < rs->cmd_buf_index) {
158         memmove(rs->cmd_buf + start,
159                 rs->cmd_buf + rs->cmd_buf_index,
160                 rs->cmd_buf_size - rs->cmd_buf_index);
161         rs->cmd_buf_size -= rs->cmd_buf_index - start;
162         rs->cmd_buf_index = start;
163     }
164 }
165 
166 static void readline_bol(ReadLineState *rs)
167 {
168     rs->cmd_buf_index = 0;
169 }
170 
171 static void readline_eol(ReadLineState *rs)
172 {
173     rs->cmd_buf_index = rs->cmd_buf_size;
174 }
175 
176 static void readline_up_char(ReadLineState *rs)
177 {
178     int idx;
179 
180     if (rs->hist_entry == 0)
181 	return;
182     if (rs->hist_entry == -1) {
183 	/* Find latest entry */
184 	for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
185 	    if (rs->history[idx] == NULL)
186 		break;
187 	}
188 	rs->hist_entry = idx;
189     }
190     rs->hist_entry--;
191     if (rs->hist_entry >= 0) {
192 	pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
193                 rs->history[rs->hist_entry]);
194 	rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
195     }
196 }
197 
198 static void readline_down_char(ReadLineState *rs)
199 {
200     if (rs->hist_entry == -1)
201         return;
202     if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
203         rs->history[++rs->hist_entry] != NULL) {
204 	pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
205                 rs->history[rs->hist_entry]);
206     } else {
207         rs->cmd_buf[0] = 0;
208 	rs->hist_entry = -1;
209     }
210     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
211 }
212 
213 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
214 {
215     char *hist_entry, *new_entry;
216     int idx;
217 
218     if (cmdline[0] == '\0')
219 	return;
220     new_entry = NULL;
221     if (rs->hist_entry != -1) {
222 	/* We were editing an existing history entry: replace it */
223 	hist_entry = rs->history[rs->hist_entry];
224 	idx = rs->hist_entry;
225 	if (strcmp(hist_entry, cmdline) == 0) {
226 	    goto same_entry;
227 	}
228     }
229     /* Search cmdline in history buffers */
230     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
231 	hist_entry = rs->history[idx];
232 	if (hist_entry == NULL)
233 	    break;
234 	if (strcmp(hist_entry, cmdline) == 0) {
235 	same_entry:
236 	    new_entry = hist_entry;
237 	    /* Put this entry at the end of history */
238 	    memmove(&rs->history[idx], &rs->history[idx + 1],
239 		    (READLINE_MAX_CMDS - (idx + 1)) * sizeof(char *));
240 	    rs->history[READLINE_MAX_CMDS - 1] = NULL;
241 	    for (; idx < READLINE_MAX_CMDS; idx++) {
242 		if (rs->history[idx] == NULL)
243 		    break;
244 	    }
245 	    break;
246 	}
247     }
248     if (idx == READLINE_MAX_CMDS) {
249 	/* Need to get one free slot */
250         g_free(rs->history[0]);
251 	memmove(rs->history, &rs->history[1],
252 	        (READLINE_MAX_CMDS - 1) * sizeof(char *));
253 	rs->history[READLINE_MAX_CMDS - 1] = NULL;
254 	idx = READLINE_MAX_CMDS - 1;
255     }
256     if (new_entry == NULL)
257         new_entry = g_strdup(cmdline);
258     rs->history[idx] = new_entry;
259     rs->hist_entry = -1;
260 }
261 
262 /* completion support */
263 
264 void readline_add_completion(ReadLineState *rs, const char *str)
265 {
266     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
267         int i;
268         for (i = 0; i < rs->nb_completions; i++) {
269             if (!strcmp(rs->completions[i], str)) {
270                 return;
271             }
272         }
273         rs->completions[rs->nb_completions++] = g_strdup(str);
274     }
275 }
276 
277 void readline_set_completion_index(ReadLineState *rs, int index)
278 {
279     rs->completion_index = index;
280 }
281 
282 static int completion_comp(const void *a, const void *b)
283 {
284     return strcmp(*(const char **) a, *(const char **) b);
285 }
286 
287 static void readline_completion(ReadLineState *rs)
288 {
289     int len, i, j, max_width, nb_cols, max_prefix;
290     char *cmdline;
291 
292     rs->nb_completions = 0;
293 
294     cmdline = g_strndup(rs->cmd_buf, rs->cmd_buf_index);
295     rs->completion_finder(rs->opaque, cmdline);
296     g_free(cmdline);
297 
298     /* no completion found */
299     if (rs->nb_completions <= 0)
300         return;
301     if (rs->nb_completions == 1) {
302         len = strlen(rs->completions[0]);
303         for(i = rs->completion_index; i < len; i++) {
304             readline_insert_char(rs, rs->completions[0][i]);
305         }
306         /* extra space for next argument. XXX: make it more generic */
307         if (len > 0 && rs->completions[0][len - 1] != '/')
308             readline_insert_char(rs, ' ');
309     } else {
310         qsort(rs->completions, rs->nb_completions, sizeof(char *),
311               completion_comp);
312         rs->printf_func(rs->opaque, "\n");
313         max_width = 0;
314         max_prefix = 0;
315         for(i = 0; i < rs->nb_completions; i++) {
316             len = strlen(rs->completions[i]);
317             if (i==0) {
318                 max_prefix = len;
319             } else {
320                 if (len < max_prefix)
321                     max_prefix = len;
322                 for(j=0; j<max_prefix; j++) {
323                     if (rs->completions[i][j] != rs->completions[0][j])
324                         max_prefix = j;
325                 }
326             }
327             if (len > max_width)
328                 max_width = len;
329         }
330         if (max_prefix > 0)
331             for(i = rs->completion_index; i < max_prefix; i++) {
332                 readline_insert_char(rs, rs->completions[0][i]);
333             }
334         max_width += 2;
335         if (max_width < 10)
336             max_width = 10;
337         else if (max_width > 80)
338             max_width = 80;
339         nb_cols = 80 / max_width;
340         j = 0;
341         for(i = 0; i < rs->nb_completions; i++) {
342             rs->printf_func(rs->opaque, "%-*s", max_width, rs->completions[i]);
343             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
344                 rs->printf_func(rs->opaque, "\n");
345                 j = 0;
346             }
347         }
348         readline_show_prompt(rs);
349     }
350     for (i = 0; i < rs->nb_completions; i++) {
351         g_free(rs->completions[i]);
352     }
353 }
354 
355 static void readline_clear_screen(ReadLineState *rs)
356 {
357     rs->printf_func(rs->opaque, "\033[2J\033[1;1H");
358     readline_show_prompt(rs);
359 }
360 
361 /* return true if command handled */
362 void readline_handle_byte(ReadLineState *rs, int ch)
363 {
364     switch(rs->esc_state) {
365     case IS_NORM:
366         switch(ch) {
367         case 1:
368             readline_bol(rs);
369             break;
370         case 4:
371             readline_delete_char(rs);
372             break;
373         case 5:
374             readline_eol(rs);
375             break;
376         case 9:
377             readline_completion(rs);
378             break;
379         case 12:
380             readline_clear_screen(rs);
381             break;
382         case 10:
383         case 13:
384             rs->cmd_buf[rs->cmd_buf_size] = '\0';
385             if (!rs->read_password)
386                 readline_hist_add(rs, rs->cmd_buf);
387             rs->printf_func(rs->opaque, "\n");
388             rs->cmd_buf_index = 0;
389             rs->cmd_buf_size = 0;
390             rs->last_cmd_buf_index = 0;
391             rs->last_cmd_buf_size = 0;
392             rs->readline_func(rs->opaque, rs->cmd_buf, rs->readline_opaque);
393             break;
394         case 23:
395             /* ^W */
396             readline_backword(rs);
397             break;
398         case 27:
399             rs->esc_state = IS_ESC;
400             break;
401         case 127:
402         case 8:
403             readline_backspace(rs);
404             break;
405 	case 155:
406             rs->esc_state = IS_CSI;
407 	    break;
408         default:
409             if (ch >= 32) {
410                 readline_insert_char(rs, ch);
411             }
412             break;
413         }
414         break;
415     case IS_ESC:
416         if (ch == '[') {
417             rs->esc_state = IS_CSI;
418             rs->esc_param = 0;
419         } else if (ch == 'O') {
420             rs->esc_state = IS_SS3;
421             rs->esc_param = 0;
422         } else {
423             rs->esc_state = IS_NORM;
424         }
425         break;
426     case IS_CSI:
427         switch(ch) {
428 	case 'A':
429 	case 'F':
430 	    readline_up_char(rs);
431 	    break;
432 	case 'B':
433 	case 'E':
434 	    readline_down_char(rs);
435 	    break;
436         case 'D':
437             readline_backward_char(rs);
438             break;
439         case 'C':
440             readline_forward_char(rs);
441             break;
442         case '0' ... '9':
443             rs->esc_param = rs->esc_param * 10 + (ch - '0');
444             goto the_end;
445         case '~':
446             switch(rs->esc_param) {
447             case 1:
448                 readline_bol(rs);
449                 break;
450             case 3:
451                 readline_delete_char(rs);
452                 break;
453             case 4:
454                 readline_eol(rs);
455                 break;
456             }
457             break;
458         default:
459             break;
460         }
461         rs->esc_state = IS_NORM;
462     the_end:
463         break;
464     case IS_SS3:
465         switch(ch) {
466         case 'F':
467             readline_eol(rs);
468             break;
469         case 'H':
470             readline_bol(rs);
471             break;
472         }
473         rs->esc_state = IS_NORM;
474         break;
475     }
476     readline_update(rs);
477 }
478 
479 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
480                     ReadLineFunc *readline_func, void *opaque)
481 {
482     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
483     rs->readline_func = readline_func;
484     rs->readline_opaque = opaque;
485     rs->read_password = read_password;
486     readline_restart(rs);
487 }
488 
489 void readline_restart(ReadLineState *rs)
490 {
491     rs->cmd_buf_index = 0;
492     rs->cmd_buf_size = 0;
493 }
494 
495 const char *readline_get_history(ReadLineState *rs, unsigned int index)
496 {
497     if (index >= READLINE_MAX_CMDS)
498         return NULL;
499     return rs->history[index];
500 }
501 
502 ReadLineState *readline_init(ReadLinePrintfFunc *printf_func,
503                              ReadLineFlushFunc *flush_func,
504                              void *opaque,
505                              ReadLineCompletionFunc *completion_finder)
506 {
507     ReadLineState *rs = g_malloc0(sizeof(*rs));
508 
509     rs->hist_entry = -1;
510     rs->opaque = opaque;
511     rs->printf_func = printf_func;
512     rs->flush_func = flush_func;
513     rs->completion_finder = completion_finder;
514 
515     return rs;
516 }
517