xref: /illumos-kvm-cmd/readline.c (revision 68396ea9)
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 #undef printf
32 #define printf do_not_use_printf
33 
readline_show_prompt(ReadLineState * rs)34 void readline_show_prompt(ReadLineState *rs)
35 {
36     monitor_printf(rs->mon, "%s", rs->prompt);
37     monitor_flush(rs->mon);
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 */
readline_update(ReadLineState * rs)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             monitor_printf(rs->mon, "\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                 monitor_printf(rs->mon, "*");
58         } else {
59             monitor_printf(rs->mon, "%s", rs->cmd_buf);
60         }
61         monitor_printf(rs->mon, "\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                 monitor_printf(rs->mon, "\033[C");
71             }
72         } else {
73             delta = -delta;
74             for(i = 0;i < delta; i++) {
75                 monitor_printf(rs->mon, "\033[D");
76             }
77         }
78         rs->last_cmd_buf_index = rs->cmd_buf_index;
79     }
80     monitor_flush(rs->mon);
81 }
82 
readline_insert_char(ReadLineState * rs,int ch)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 
readline_backward_char(ReadLineState * rs)95 static void readline_backward_char(ReadLineState *rs)
96 {
97     if (rs->cmd_buf_index > 0) {
98         rs->cmd_buf_index--;
99     }
100 }
101 
readline_forward_char(ReadLineState * rs)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 
readline_delete_char(ReadLineState * rs)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 
readline_backspace(ReadLineState * rs)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 
readline_backword(ReadLineState * rs)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 
readline_bol(ReadLineState * rs)166 static void readline_bol(ReadLineState *rs)
167 {
168     rs->cmd_buf_index = 0;
169 }
170 
readline_eol(ReadLineState * rs)171 static void readline_eol(ReadLineState *rs)
172 {
173     rs->cmd_buf_index = rs->cmd_buf_size;
174 }
175 
readline_up_char(ReadLineState * rs)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 
readline_down_char(ReadLineState * rs)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 
readline_hist_add(ReadLineState * rs,const char * cmdline)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 	free(rs->history[0]);
251 	memcpy(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 = strdup(cmdline);
258     rs->history[idx] = new_entry;
259     rs->hist_entry = -1;
260 }
261 
262 /* completion support */
263 
readline_add_completion(ReadLineState * rs,const char * str)264 void readline_add_completion(ReadLineState *rs, const char *str)
265 {
266     if (rs->nb_completions < READLINE_MAX_COMPLETIONS) {
267         rs->completions[rs->nb_completions++] = qemu_strdup(str);
268     }
269 }
270 
readline_set_completion_index(ReadLineState * rs,int index)271 void readline_set_completion_index(ReadLineState *rs, int index)
272 {
273     rs->completion_index = index;
274 }
275 
readline_completion(ReadLineState * rs)276 static void readline_completion(ReadLineState *rs)
277 {
278     Monitor *mon = cur_mon;
279     int len, i, j, max_width, nb_cols, max_prefix;
280     char *cmdline;
281 
282     rs->nb_completions = 0;
283 
284     cmdline = qemu_malloc(rs->cmd_buf_index + 1);
285     memcpy(cmdline, rs->cmd_buf, rs->cmd_buf_index);
286     cmdline[rs->cmd_buf_index] = '\0';
287     rs->completion_finder(cmdline);
288     qemu_free(cmdline);
289 
290     /* no completion found */
291     if (rs->nb_completions <= 0)
292         return;
293     if (rs->nb_completions == 1) {
294         len = strlen(rs->completions[0]);
295         for(i = rs->completion_index; i < len; i++) {
296             readline_insert_char(rs, rs->completions[0][i]);
297         }
298         /* extra space for next argument. XXX: make it more generic */
299         if (len > 0 && rs->completions[0][len - 1] != '/')
300             readline_insert_char(rs, ' ');
301     } else {
302         monitor_printf(mon, "\n");
303         max_width = 0;
304         max_prefix = 0;
305         for(i = 0; i < rs->nb_completions; i++) {
306             len = strlen(rs->completions[i]);
307             if (i==0) {
308                 max_prefix = len;
309             } else {
310                 if (len < max_prefix)
311                     max_prefix = len;
312                 for(j=0; j<max_prefix; j++) {
313                     if (rs->completions[i][j] != rs->completions[0][j])
314                         max_prefix = j;
315                 }
316             }
317             if (len > max_width)
318                 max_width = len;
319         }
320         if (max_prefix > 0)
321             for(i = rs->completion_index; i < max_prefix; i++) {
322                 readline_insert_char(rs, rs->completions[0][i]);
323             }
324         max_width += 2;
325         if (max_width < 10)
326             max_width = 10;
327         else if (max_width > 80)
328             max_width = 80;
329         nb_cols = 80 / max_width;
330         j = 0;
331         for(i = 0; i < rs->nb_completions; i++) {
332             monitor_printf(rs->mon, "%-*s", max_width, rs->completions[i]);
333             if (++j == nb_cols || i == (rs->nb_completions - 1)) {
334                 monitor_printf(rs->mon, "\n");
335                 j = 0;
336             }
337         }
338         readline_show_prompt(rs);
339     }
340 }
341 
342 /* return true if command handled */
readline_handle_byte(ReadLineState * rs,int ch)343 void readline_handle_byte(ReadLineState *rs, int ch)
344 {
345     switch(rs->esc_state) {
346     case IS_NORM:
347         switch(ch) {
348         case 1:
349             readline_bol(rs);
350             break;
351         case 4:
352             readline_delete_char(rs);
353             break;
354         case 5:
355             readline_eol(rs);
356             break;
357         case 9:
358             readline_completion(rs);
359             break;
360         case 10:
361         case 13:
362             rs->cmd_buf[rs->cmd_buf_size] = '\0';
363             if (!rs->read_password)
364                 readline_hist_add(rs, rs->cmd_buf);
365             monitor_printf(rs->mon, "\n");
366             rs->cmd_buf_index = 0;
367             rs->cmd_buf_size = 0;
368             rs->last_cmd_buf_index = 0;
369             rs->last_cmd_buf_size = 0;
370             rs->readline_func(rs->mon, rs->cmd_buf, rs->readline_opaque);
371             break;
372         case 23:
373             /* ^W */
374             readline_backword(rs);
375             break;
376         case 27:
377             rs->esc_state = IS_ESC;
378             break;
379         case 127:
380         case 8:
381             readline_backspace(rs);
382             break;
383 	case 155:
384             rs->esc_state = IS_CSI;
385 	    break;
386         default:
387             if (ch >= 32) {
388                 readline_insert_char(rs, ch);
389             }
390             break;
391         }
392         break;
393     case IS_ESC:
394         if (ch == '[') {
395             rs->esc_state = IS_CSI;
396             rs->esc_param = 0;
397         } else {
398             rs->esc_state = IS_NORM;
399         }
400         break;
401     case IS_CSI:
402         switch(ch) {
403 	case 'A':
404 	case 'F':
405 	    readline_up_char(rs);
406 	    break;
407 	case 'B':
408 	case 'E':
409 	    readline_down_char(rs);
410 	    break;
411         case 'D':
412             readline_backward_char(rs);
413             break;
414         case 'C':
415             readline_forward_char(rs);
416             break;
417         case '0' ... '9':
418             rs->esc_param = rs->esc_param * 10 + (ch - '0');
419             goto the_end;
420         case '~':
421             switch(rs->esc_param) {
422             case 1:
423                 readline_bol(rs);
424                 break;
425             case 3:
426                 readline_delete_char(rs);
427                 break;
428             case 4:
429                 readline_eol(rs);
430                 break;
431             }
432             break;
433         default:
434             break;
435         }
436         rs->esc_state = IS_NORM;
437     the_end:
438         break;
439     }
440     readline_update(rs);
441 }
442 
readline_start(ReadLineState * rs,const char * prompt,int read_password,ReadLineFunc * readline_func,void * opaque)443 void readline_start(ReadLineState *rs, const char *prompt, int read_password,
444                     ReadLineFunc *readline_func, void *opaque)
445 {
446     pstrcpy(rs->prompt, sizeof(rs->prompt), prompt);
447     rs->readline_func = readline_func;
448     rs->readline_opaque = opaque;
449     rs->read_password = read_password;
450     readline_restart(rs);
451 }
452 
readline_restart(ReadLineState * rs)453 void readline_restart(ReadLineState *rs)
454 {
455     rs->cmd_buf_index = 0;
456     rs->cmd_buf_size = 0;
457 }
458 
readline_get_history(ReadLineState * rs,unsigned int index)459 const char *readline_get_history(ReadLineState *rs, unsigned int index)
460 {
461     if (index >= READLINE_MAX_CMDS)
462         return NULL;
463     return rs->history[index];
464 }
465 
readline_init(Monitor * mon,ReadLineCompletionFunc * completion_finder)466 ReadLineState *readline_init(Monitor *mon,
467                              ReadLineCompletionFunc *completion_finder)
468 {
469     ReadLineState *rs = qemu_mallocz(sizeof(*rs));
470 
471     rs->hist_entry = -1;
472     rs->mon = mon;
473     rs->completion_finder = completion_finder;
474 
475     return rs;
476 }
477