kvm: Improve upgrade notes when facing unsupported kernels
[qemu] / readline.c
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 #include "readline.h"
25 #include "monitor.h"
26
27 #define IS_NORM 0
28 #define IS_ESC  1
29 #define IS_CSI  2
30
31 #define printf do_not_use_printf
32
33 void readline_show_prompt(ReadLineState *rs)
34 {
35     monitor_printf(rs->mon, "%s", rs->prompt);
36     monitor_flush(rs->mon);
37     rs->last_cmd_buf_index = 0;
38     rs->last_cmd_buf_size = 0;
39     rs->esc_state = IS_NORM;
40 }
41
42 /* update the displayed command line */
43 static void readline_update(ReadLineState *rs)
44 {
45     int i, delta, len;
46
47     if (rs->cmd_buf_size != rs->last_cmd_buf_size ||
48         memcmp(rs->cmd_buf, rs->last_cmd_buf, rs->cmd_buf_size) != 0) {
49         for(i = 0; i < rs->last_cmd_buf_index; i++) {
50             monitor_printf(rs->mon, "\033[D");
51         }
52         rs->cmd_buf[rs->cmd_buf_size] = '\0';
53         if (rs->read_password) {
54             len = strlen(rs->cmd_buf);
55             for(i = 0; i < len; i++)
56                 monitor_printf(rs->mon, "*");
57         } else {
58             monitor_printf(rs->mon, "%s", rs->cmd_buf);
59         }
60         monitor_printf(rs->mon, "\033[K");
61         memcpy(rs->last_cmd_buf, rs->cmd_buf, rs->cmd_buf_size);
62         rs->last_cmd_buf_size = rs->cmd_buf_size;
63         rs->last_cmd_buf_index = rs->cmd_buf_size;
64     }
65     if (rs->cmd_buf_index != rs->last_cmd_buf_index) {
66         delta = rs->cmd_buf_index - rs->last_cmd_buf_index;
67         if (delta > 0) {
68             for(i = 0;i < delta; i++) {
69                 monitor_printf(rs->mon, "\033[C");
70             }
71         } else {
72             delta = -delta;
73             for(i = 0;i < delta; i++) {
74                 monitor_printf(rs->mon, "\033[D");
75             }
76         }
77         rs->last_cmd_buf_index = rs->cmd_buf_index;
78     }
79     monitor_flush(rs->mon);
80 }
81
82 static void readline_insert_char(ReadLineState *rs, int ch)
83 {
84     if (rs->cmd_buf_index < READLINE_CMD_BUF_SIZE) {
85         memmove(rs->cmd_buf + rs->cmd_buf_index + 1,
86                 rs->cmd_buf + rs->cmd_buf_index,
87                 rs->cmd_buf_size - rs->cmd_buf_index);
88         rs->cmd_buf[rs->cmd_buf_index] = ch;
89         rs->cmd_buf_size++;
90         rs->cmd_buf_index++;
91     }
92 }
93
94 static void readline_backward_char(ReadLineState *rs)
95 {
96     if (rs->cmd_buf_index > 0) {
97         rs->cmd_buf_index--;
98     }
99 }
100
101 static void readline_forward_char(ReadLineState *rs)
102 {
103     if (rs->cmd_buf_index < rs->cmd_buf_size) {
104         rs->cmd_buf_index++;
105     }
106 }
107
108 static void readline_delete_char(ReadLineState *rs)
109 {
110     if (rs->cmd_buf_index < rs->cmd_buf_size) {
111         memmove(rs->cmd_buf + rs->cmd_buf_index,
112                 rs->cmd_buf + rs->cmd_buf_index + 1,
113                 rs->cmd_buf_size - rs->cmd_buf_index - 1);
114         rs->cmd_buf_size--;
115     }
116 }
117
118 static void readline_backspace(ReadLineState *rs)
119 {
120     if (rs->cmd_buf_index > 0) {
121         readline_backward_char(rs);
122         readline_delete_char(rs);
123     }
124 }
125
126 static void readline_backword(ReadLineState *rs)
127 {
128     int start;
129
130     if (rs->cmd_buf_index == 0 || rs->cmd_buf_index > rs->cmd_buf_size) {
131         return;
132     }
133
134     start = rs->cmd_buf_index - 1;
135
136     /* find first word (backwards) */
137     while (start > 0) {
138         if (!qemu_isspace(rs->cmd_buf[start])) {
139             break;
140         }
141
142         --start;
143     }
144
145     /* find first space (backwards) */
146     while (start > 0) {
147         if (qemu_isspace(rs->cmd_buf[start])) {
148             ++start;
149             break;
150         }
151
152         --start;
153     }
154
155     /* remove word */
156     if (start < rs->cmd_buf_index) {
157         memmove(rs->cmd_buf + start,
158                 rs->cmd_buf + rs->cmd_buf_index,
159                 rs->cmd_buf_size - rs->cmd_buf_index);
160         rs->cmd_buf_size -= rs->cmd_buf_index - start;
161         rs->cmd_buf_index = start;
162     }
163 }
164
165 static void readline_bol(ReadLineState *rs)
166 {
167     rs->cmd_buf_index = 0;
168 }
169
170 static void readline_eol(ReadLineState *rs)
171 {
172     rs->cmd_buf_index = rs->cmd_buf_size;
173 }
174
175 static void readline_up_char(ReadLineState *rs)
176 {
177     int idx;
178
179     if (rs->hist_entry == 0)
180         return;
181     if (rs->hist_entry == -1) {
182         /* Find latest entry */
183         for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
184             if (rs->history[idx] == NULL)
185                 break;
186         }
187         rs->hist_entry = idx;
188     }
189     rs->hist_entry--;
190     if (rs->hist_entry >= 0) {
191         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
192                 rs->history[rs->hist_entry]);
193         rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
194     }
195 }
196
197 static void readline_down_char(ReadLineState *rs)
198 {
199     if (rs->hist_entry == -1)
200         return;
201     if (rs->hist_entry < READLINE_MAX_CMDS - 1 &&
202         rs->history[++rs->hist_entry] != NULL) {
203         pstrcpy(rs->cmd_buf, sizeof(rs->cmd_buf),
204                 rs->history[rs->hist_entry]);
205     } else {
206         rs->cmd_buf[0] = 0;
207         rs->hist_entry = -1;
208     }
209     rs->cmd_buf_index = rs->cmd_buf_size = strlen(rs->cmd_buf);
210 }
211
212 static void readline_hist_add(ReadLineState *rs, const char *cmdline)
213 {
214     char *hist_entry, *new_entry;
215     int idx;
216
217     if (cmdline[0] == '\0')
218         return;
219     new_entry = NULL;
220     if (rs->hist_entry != -1) {
221         /* We were editing an existing history entry: replace it */
222         hist_entry = rs->history[rs->hist_entry];
223         idx = rs->hist_entry;
224         if (strcmp(hist_entry, cmdline) == 0) {
225             goto same_entry;
226         }
227     }
228     /* Search cmdline in history buffers */
229     for (idx = 0; idx < READLINE_MAX_CMDS; idx++) {
230         hist_entry = rs->history[idx];
231         if (hist_entry == NULL)
232             break;
233         if (strcmp(hist_entry, cmdline) == 0) {
234         same_entry:
235             new_entry = hist_entry;
236             /* Put this entry at the end of history */
237             memmove(&rs->history[idx], &rs->history[idx + 1],
238                     (READLINE_MAX_CMDS - idx + 1) * sizeof(char *));
239             rs->history[READLINE_MAX_CMDS - 1] = NULL;
240             for (; idx < READLINE_MAX_CMDS; idx++) {
241                 if (rs->history[idx] == NULL)
242                     break;
243             }
244             break;
245         }
246     }
247     if (idx == READLINE_MAX_CMDS) {
248         /* Need to get one free slot */
249         free(rs->history[0]);
250         memcpy(rs->history, &rs->history[1],
251                (READLINE_MAX_CMDS - 1) * sizeof(char *));
252         rs->history[READLINE_MAX_CMDS - 1] = NULL;
253         idx = READLINE_MAX_CMDS - 1;
254     }
255     if (new_entry == NULL)
256         new_entry = strdup(cmdline);
257     rs->history[idx] = new_entry;
258     rs->hist_entry = -1;
259 }
260
261 /* completion support */
262
263 void readline_add_completion(ReadLineState *rs, const char *str)
264 {
265     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
266         rs->completions[rs->nb_completions++] = qemu_strdup(str);
267     }
268 }
269
270 void readline_set_completion_index(ReadLineState *rs, int index)
271 {
272     rs->completion_index = index;
273 }
274
275 static void readline_completion(ReadLineState *rs)
276 {
277     Monitor *mon = cur_mon;
278     int len, i, j, max_width, nb_cols, max_prefix;
279     char *cmdline;
280
281     rs->nb_completions = 0;
282
283     cmdline = qemu_malloc(rs->cmd_buf_index + 1);
284     memcpy(cmdline, rs->cmd_buf, rs->cmd_buf_index);
285     cmdline[rs->cmd_buf_index] = '\0';
286     rs->completion_finder(cmdline);
287     qemu_free(cmdline);
288
289     /* no completion found */
290     if (rs->nb_completions <= 0)
291         return;
292     if (rs->nb_completions == 1) {
293         len = strlen(rs->completions[0]);
294         for(i = rs->completion_index; i < len; i++) {
295             readline_insert_char(rs, rs->completions[0][i]);
296         }
297         /* extra space for next argument. XXX: make it more generic */
298         if (len > 0 && rs->completions[0][len - 1] != '/')
299             readline_insert_char(rs, ' ');
300     } else {
301         monitor_printf(mon, "\n");
302         max_width = 0;
303         max_prefix = 0; 
304         for(i = 0; i < rs->nb_completions; i++) {
305             len = strlen(rs->completions[i]);
306             if (i==0) {
307                 max_prefix = len;
308             } else {
309                 if (len < max_prefix)
310                     max_prefix = len;
311                 for(j=0; j<max_prefix; j++) {
312                     if (rs->completions[i][j] != rs->completions[0][j])
313                         max_prefix = j;
314                 }
315             }
316             if (len > max_width)
317                 max_width = len;
318         }
319         if (max_prefix > 0) 
320             for(i = rs->completion_index; i < max_prefix; i++) {
321                 readline_insert_char(rs, rs->completions[0][i]);
322             }
323         max_width += 2;
324         if (max_width < 10)
325             max_width = 10;
326         else if (max_width > 80)
327             max_width = 80;
328         nb_cols = 80 / max_width;
329         j = 0;
330         for(i = 0; i < rs->nb_completions; i++) {
331             monitor_printf(rs->mon, "%-*s", max_width, rs->completions[i]);
332             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
333                 monitor_printf(rs->mon, "\n");
334                 j = 0;
335             }
336         }
337         readline_show_prompt(rs);
338     }
339 }
340
341 /* return true if command handled */
342 void readline_handle_byte(ReadLineState *rs, int ch)
343 {
344     switch(rs->esc_state) {
345     case IS_NORM:
346         switch(ch) {
347         case 1:
348             readline_bol(rs);
349             break;
350         case 4:
351             readline_delete_char(rs);
352             break;
353         case 5:
354             readline_eol(rs);
355             break;
356         case 9:
357             readline_completion(rs);
358             break;
359         case 10:
360         case 13:
361             rs->cmd_buf[rs->cmd_buf_size] = '\0';
362             if (!rs->read_password)
363                 readline_hist_add(rs, rs->cmd_buf);
364             monitor_printf(rs->mon, "\n");
365             rs->cmd_buf_index = 0;
366             rs->cmd_buf_size = 0;
367             rs->last_cmd_buf_index = 0;
368             rs->last_cmd_buf_size = 0;
369             rs->readline_func(rs->mon, rs->cmd_buf, rs->readline_opaque);
370             break;
371         case 23:
372             /* ^W */
373             readline_backword(rs);
374             break;
375         case 27:
376             rs->esc_state = IS_ESC;
377             break;
378         case 127:
379         case 8:
380             readline_backspace(rs);
381             break;
382         case 155:
383             rs->esc_state = IS_CSI;
384             break;
385         default:
386             if (ch >= 32) {
387                 readline_insert_char(rs, ch);
388             }
389             break;
390         }
391         break;
392     case IS_ESC:
393         if (ch == '[') {
394             rs->esc_state = IS_CSI;
395             rs->esc_param = 0;
396         } else {
397             rs->esc_state = IS_NORM;
398         }
399         break;
400     case IS_CSI:
401         switch(ch) {
402         case 'A':
403         case 'F':
404             readline_up_char(rs);
405             break;
406         case 'B':
407         case 'E':
408             readline_down_char(rs);
409             break;
410         case 'D':
411             readline_backward_char(rs);
412             break;
413         case 'C':
414             readline_forward_char(rs);
415             break;
416         case '0' ... '9':
417             rs->esc_param = rs->esc_param * 10 + (ch - '0');
418             goto the_end;
419         case '~':
420             switch(rs->esc_param) {
421             case 1:
422                 readline_bol(rs);
423                 break;
424             case 3:
425                 readline_delete_char(rs);
426                 break;
427             case 4:
428                 readline_eol(rs);
429                 break;
430             }
431             break;
432         default:
433             break;
434         }
435         rs->esc_state = IS_NORM;
436     the_end:
437         break;
438     }
439     readline_update(rs);
440 }
441
442 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
443                     ReadLineFunc *readline_func, void *opaque)
444 {
445     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
446     rs->readline_func = readline_func;
447     rs->readline_opaque = opaque;
448     rs->read_password = read_password;
449     readline_restart(rs);
450 }
451
452 void readline_restart(ReadLineState *rs)
453 {
454     rs->cmd_buf_index = 0;
455     rs->cmd_buf_size = 0;
456 }
457
458 const char *readline_get_history(ReadLineState *rs, unsigned int index)
459 {
460     if (index >= READLINE_MAX_CMDS)
461         return NULL;
462     return rs->history[index];
463 }
464
465 ReadLineState *readline_init(Monitor *mon,
466                              ReadLineCompletionFunc *completion_finder)
467 {
468     ReadLineState *rs = qemu_mallocz(sizeof(*rs));
469
470     if (!rs)
471         return NULL;
472
473     rs->hist_entry = -1;
474     rs->mon = mon;
475     rs->completion_finder = completion_finder;
476
477     return rs;
478 }