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      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 
     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 */
     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 
     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 	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 
    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 
    271 void readline_set_completion_index(ReadLineState *rs, int index)
    272 {
    273     rs->completion_index = index;
    274 }
    275 
    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 */
    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 
    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 
    453 void readline_restart(ReadLineState *rs)
    454 {
    455     rs->cmd_buf_index = 0;
    456     rs->cmd_buf_size = 0;
    457 }
    458 
    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 
    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 
    478 void readline_free(ReadLineState *rs)
    479 {
    480     if (rs) {
    481         rs->mon = NULL;
    482         rs->completion_finder = NULL;
    483         qemu_free(rs);
    484     }
    485 }
    486