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1.1 etheisen 1: /*
2: * Copyright (c) 1984,1985,1989,1994,1995 Mark Nudelman
3: * All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice in the documentation and/or other materials provided with
12: * the distribution.
13: *
14: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY
15: * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
17: * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR BE LIABLE
18: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
19: * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
20: * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR
21: * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
22: * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE
23: * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN
24: * IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25: */
26:
27:
28: /*
29: * Routines to decode user commands.
30: *
31: * This is all table driven.
32: * A command table is a sequence of command descriptors.
33: * Each command descriptor is a sequence of bytes with the following format:
34: * <c1><c2>...<cN><0><action>
35: * The characters c1,c2,...,cN are the command string; that is,
36: * the characters which the user must type.
37: * It is terminated by a null <0> byte.
38: * The byte after the null byte is the action code associated
39: * with the command string.
40: * If an action byte is OR-ed with A_EXTRA, this indicates
41: * that the option byte is followed by an extra string.
42: *
43: * There may be many command tables.
44: * The first (default) table is built-in.
45: * Other tables are read in from "lesskey" files.
46: * All the tables are linked together and are searched in order.
47: */
48:
49: #include "less.h"
50: #include "cmd.h"
51: #include "lesskey.h"
52:
53: extern int erase_char, kill_char;
54:
55: /*
56: * Command table is ordered roughly according to expected
57: * frequency of use, so the common commands are near the beginning.
58: */
59: static unsigned char cmdtable[] =
60: {
61: '\r',0, A_F_LINE,
62: '\n',0, A_F_LINE,
63: 'e',0, A_F_LINE,
64: 'j',0, A_F_LINE,
65: CONTROL('E'),0, A_F_LINE,
66: CONTROL('N'),0, A_F_LINE,
67: 'k',0, A_B_LINE,
68: 'y',0, A_B_LINE,
69: CONTROL('Y'),0, A_B_LINE,
70: CONTROL('K'),0, A_B_LINE,
71: CONTROL('P'),0, A_B_LINE,
72: 'J',0, A_FF_LINE,
73: 'K',0, A_BF_LINE,
74: 'Y',0, A_BF_LINE,
75: 'd',0, A_F_SCROLL,
76: CONTROL('D'),0, A_F_SCROLL,
77: 'u',0, A_B_SCROLL,
78: CONTROL('U'),0, A_B_SCROLL,
79: ' ',0, A_F_SCREEN,
80: 'f',0, A_F_SCREEN,
81: CONTROL('F'),0, A_F_SCREEN,
82: CONTROL('V'),0, A_F_SCREEN,
83: 'b',0, A_B_SCREEN,
84: CONTROL('B'),0, A_B_SCREEN,
85: ESC,'v',0, A_B_SCREEN,
86: 'z',0, A_F_WINDOW,
87: 'w',0, A_B_WINDOW,
88: 'F',0, A_F_FOREVER,
89: 'R',0, A_FREPAINT,
90: 'r',0, A_REPAINT,
91: CONTROL('R'),0, A_REPAINT,
92: CONTROL('L'),0, A_REPAINT,
93: ESC,'u',0, A_UNDO_SEARCH,
94: 'g',0, A_GOLINE,
95: '<',0, A_GOLINE,
96: ESC,'<',0, A_GOLINE,
97: 'p',0, A_PERCENT,
98: '%',0, A_PERCENT,
99: '{',0, A_F_BRACKET|A_EXTRA, '{','}',0,
100: '}',0, A_B_BRACKET|A_EXTRA, '{','}',0,
101: '(',0, A_F_BRACKET|A_EXTRA, '(',')',0,
102: ')',0, A_B_BRACKET|A_EXTRA, '(',')',0,
103: '[',0, A_F_BRACKET|A_EXTRA, '[',']',0,
104: ']',0, A_B_BRACKET|A_EXTRA, '[',']',0,
105: ESC,CONTROL('F'),0, A_F_BRACKET,
106: ESC,CONTROL('B'),0, A_B_BRACKET,
107: 'G',0, A_GOEND,
108: ESC,'>',0, A_GOEND,
109: '>',0, A_GOEND,
110: 'P',0, A_GOPOS,
111:
112: '0',0, A_DIGIT,
113: '1',0, A_DIGIT,
114: '2',0, A_DIGIT,
115: '3',0, A_DIGIT,
116: '4',0, A_DIGIT,
117: '5',0, A_DIGIT,
118: '6',0, A_DIGIT,
119: '7',0, A_DIGIT,
120: '8',0, A_DIGIT,
121: '9',0, A_DIGIT,
122:
123: '=',0, A_STAT,
124: CONTROL('G'),0, A_STAT,
125: ':','f',0, A_STAT,
126: '/',0, A_F_SEARCH,
127: '?',0, A_B_SEARCH,
128: ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
129: ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
130: 'n',0, A_AGAIN_SEARCH,
131: ESC,'n',0, A_T_AGAIN_SEARCH,
132: 'N',0, A_REVERSE_SEARCH,
133: ESC,'N',0, A_T_REVERSE_SEARCH,
134: 'm',0, A_SETMARK,
135: '\'',0, A_GOMARK,
136: CONTROL('X'),CONTROL('X'),0, A_GOMARK,
137: 'E',0, A_EXAMINE,
138: ':','e',0, A_EXAMINE,
139: CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
140: ':','n',0, A_NEXT_FILE,
141: ':','p',0, A_PREV_FILE,
142: ':','x',0, A_INDEX_FILE,
143: '-',0, A_OPT_TOGGLE,
144: ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
145: 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
146: '_',0, A_DISP_OPTION,
147: '|',0, A_PIPE,
148: 'v',0, A_VISUAL,
149: '!',0, A_SHELL,
150: '+',0, A_FIRSTCMD,
151:
152: 'H',0, A_HELP,
153: 'h',0, A_HELP,
154: 'V',0, A_VERSION,
155: 'q',0, A_QUIT,
156: ':','q',0, A_QUIT,
157: ':','Q',0, A_QUIT,
158: 'Z','Z',0, A_QUIT
159: };
160:
161: static unsigned char edittable[] =
162: {
163: '\t',0, EC_F_COMPLETE, /* TAB */
164: '\17',0, EC_B_COMPLETE, /* BACKTAB */
165: '\14',0, EC_EXPAND, /* CTRL-L */
166: CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
167: CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
168: ESC,'l',0, EC_RIGHT, /* ESC l */
169: ESC,'h',0, EC_LEFT, /* ESC h */
170: ESC,'b',0, EC_W_LEFT, /* ESC b */
171: ESC,'w',0, EC_W_RIGHT, /* ESC w */
172: ESC,'i',0, EC_INSERT, /* ESC i */
173: ESC,'x',0, EC_DELETE, /* ESC x */
174: ESC,'X',0, EC_W_DELETE, /* ESC X */
175: ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
176: ESC,'0',0, EC_HOME, /* ESC 0 */
177: ESC,'$',0, EC_END, /* ESC $ */
178: ESC,'k',0, EC_UP, /* ESC k */
179: ESC,'j',0, EC_DOWN, /* ESC j */
180: ESC,'\t',0, EC_B_COMPLETE /* ESC TAB */
181: };
182:
183: /*
184: * Structure to support a list of command tables.
185: */
186: struct tablelist
187: {
188: struct tablelist *t_next;
189: char *t_start;
190: char *t_end;
191: };
192:
193: /*
194: * List of command tables and list of line-edit tables.
195: */
196: static struct tablelist *list_fcmd_tables = NULL;
197: static struct tablelist *list_ecmd_tables = NULL;
198:
199:
200: /*
201: * Initialize the command lists.
202: */
203: public void
204: init_cmds()
205: {
206: /*
207: * Add the default command tables.
208: */
209: add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
210: add_ecmd_table((char*)edittable, sizeof(edittable));
211: get_editkeys();
212: #if USERFILE
213: /*
214: * Try to add the tables in the standard lesskey file "$HOME/.less".
215: */
216: add_hometable();
217: #endif
218: }
219:
220: /*
221: *
222: */
223: static int
224: add_cmd_table(tlist, buf, len)
225: struct tablelist **tlist;
226: char *buf;
227: int len;
228: {
229: register struct tablelist *t;
230:
231: if (len == 0)
232: return (0);
233: /*
234: * Allocate a tablelist structure, initialize it,
235: * and link it into the list of tables.
236: */
237: if ((t = (struct tablelist *)
238: calloc(1, sizeof(struct tablelist))) == NULL)
239: {
240: return (-1);
241: }
242: t->t_start = buf;
243: t->t_end = buf + len;
244: t->t_next = *tlist;
245: *tlist = t;
246: return (0);
247: }
248:
249: /*
250: * Add a command table.
251: */
252: public void
253: add_fcmd_table(buf, len)
254: char *buf;
255: int len;
256: {
257: if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
258: error("Warning: some commands disabled", NULL_PARG);
259: }
260:
261: /*
262: * Add an editing command table.
263: */
264: public void
265: add_ecmd_table(buf, len)
266: char *buf;
267: int len;
268: {
269: if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
270: error("Warning: some edit commands disabled", NULL_PARG);
271: }
272:
273: /*
274: * Search a single command table for the command string in cmd.
275: */
276: public int
277: cmd_search(cmd, table, endtable, sp)
278: char *cmd;
279: char *table;
280: char *endtable;
281: char **sp;
282: {
283: register char *p;
284: register char *q;
285: register int a;
286:
287: for (p = table, q = cmd; p < endtable; p++, q++)
288: {
289: if (*p == *q)
290: {
291: /*
292: * Current characters match.
293: * If we're at the end of the string, we've found it.
294: * Return the action code, which is the character
295: * after the null at the end of the string
296: * in the command table.
297: */
298: if (*p == '\0')
299: {
300: a = *++p & 0377;
301: if (a == A_END_LIST)
302: {
303: /*
304: * We get here only if the original
305: * cmd string passed in was empty ("").
306: * I don't think that can happen,
307: * but just in case ...
308: */
309: return (A_UINVALID);
310: }
311: /*
312: * Check for an "extra" string.
313: */
314: if (a & A_EXTRA)
315: {
316: *sp = ++p;
317: a &= ~A_EXTRA;
318: } else
319: *sp = NULL;
320: return (a);
321: }
322: } else if (*q == '\0')
323: {
324: /*
325: * Hit the end of the user's command,
326: * but not the end of the string in the command table.
327: * The user's command is incomplete.
328: */
329: return (A_PREFIX);
330: } else
331: {
332: /*
333: * Not a match.
334: * Skip ahead to the next command in the
335: * command table, and reset the pointer
336: * to the beginning of the user's command.
337: */
338: if (*p == '\0' && p[1] == A_END_LIST)
339: {
340: /*
341: * A_END_LIST is a special marker that tells
342: * us to abort the cmd search.
343: */
344: return (A_UINVALID);
345: }
346: while (*p++ != '\0') ;
347: if (*p & A_EXTRA)
348: while (*++p != '\0') ;
349: q = cmd-1;
350: }
351: }
352: /*
353: * No match found in the entire command table.
354: */
355: return (A_INVALID);
356: }
357:
358: /*
359: * Decode a command character and return the associated action.
360: * The "extra" string, if any, is returned in sp.
361: */
362: static int
363: cmd_decode(tlist, cmd, sp)
364: struct tablelist *tlist;
365: char *cmd;
366: char **sp;
367: {
368: register struct tablelist *t;
369: register int action = A_INVALID;
370:
371: /*
372: * Search thru all the command tables.
373: * Stop when we find an action which is not A_INVALID.
374: */
375: for (t = tlist; t != NULL; t = t->t_next)
376: {
377: action = cmd_search(cmd, t->t_start, t->t_end, sp);
378: if (action != A_INVALID)
379: break;
380: }
381: return (action);
382: }
383:
384: /*
385: * Decode a command from the cmdtables list.
386: */
387: public int
388: fcmd_decode(cmd, sp)
389: char *cmd;
390: char **sp;
391: {
392: return (cmd_decode(list_fcmd_tables, cmd, sp));
393: }
394:
395: /*
396: * Decode a command from the edittables list.
397: */
398: public int
399: ecmd_decode(cmd, sp)
400: char *cmd;
401: char **sp;
402: {
403: return (cmd_decode(list_ecmd_tables, cmd, sp));
404: }
405:
406: #if USERFILE
407: static int
408: gint(sp)
409: char **sp;
410: {
411: int n;
412:
413: n = *(*sp)++;
414: n += *(*sp)++ * KRADIX;
415: return (n);
416: }
417:
418: static int
419: old_lesskey(buf, len)
420: char *buf;
421: int len;
422: {
423: /*
424: * Old-style lesskey file.
425: * The file must end with either
426: * ...,cmd,0,action
427: * or ...,cmd,0,action|A_EXTRA,string,0
428: * So the last byte or the second to last byte must be zero.
429: */
430: if (buf[len-1] != '\0' && buf[len-2] != '\0')
431: return (-1);
432: add_fcmd_table(buf, len);
433: return (0);
434: }
435:
436: static int
437: new_lesskey(buf, len)
438: char *buf;
439: int len;
440: {
441: char *p;
442: register int c;
443: register int done;
444: register int n;
445:
446: /*
447: * New-style lesskey file.
448: * Extract the pieces.
449: */
450: if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
451: buf[len-2] != C1_END_LESSKEY_MAGIC ||
452: buf[len-1] != C2_END_LESSKEY_MAGIC)
453: return (-1);
454: p = buf + 4;
455: done = 0;
456: while (!done)
457: {
458: c = *p++;
459: switch (c)
460: {
461: case CMD_SECTION:
462: n = gint(&p);
463: add_fcmd_table(p, n);
464: p += n;
465: break;
466: case EDIT_SECTION:
467: n = gint(&p);
468: add_ecmd_table(p, n);
469: p += n;
470: break;
471: case END_SECTION:
472: done = 1;
473: break;
474: default:
475: free(buf);
476: return (-1);
477: }
478: }
479: return (0);
480: }
481:
482: /*
483: * Set up a user command table, based on a "lesskey" file.
484: */
485: public int
486: lesskey(filename)
487: char *filename;
488: {
489: register char *buf;
490: register POSITION len;
491: register long n;
492: register int f;
493:
494: /*
495: * Try to open the lesskey file.
496: */
497: f = open(filename, OPEN_READ);
498: if (f < 0)
499: return (1);
500:
501: /*
502: * Read the file into a buffer.
503: * We first figure out the size of the file and allocate space for it.
504: * {{ Minimal error checking is done here.
505: * A garbage .less file will produce strange results.
506: * To avoid a large amount of error checking code here, we
507: * rely on the lesskey program to generate a good .less file. }}
508: */
509: len = filesize(f);
510: if (len == NULL_POSITION || len < 3)
511: {
512: /*
513: * Bad file (valid file must have at least 3 chars).
514: */
515: close(f);
516: return (-1);
517: }
518: if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
519: {
520: close(f);
521: return (-1);
522: }
523: if (lseek(f, (off_t)0, 0) == BAD_LSEEK)
524: {
525: free(buf);
526: close(f);
527: return (-1);
528: }
529: n = read(f, buf, (unsigned int) len);
530: close(f);
531: if (n != len)
532: {
533: free(buf);
534: return (-1);
535: }
536:
537: /*
538: * Figure out if this is an old-style (before version 241)
539: * or new-style lesskey file format.
540: */
541: if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
542: buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
543: return (old_lesskey(buf, (int)len));
544: return (new_lesskey(buf, (int)len));
545: }
546:
547: /*
548: * Add the standard lesskey file "$HOME/.less"
549: */
550: public void
551: add_hometable()
552: {
553: char *filename;
554: PARG parg;
555:
556: filename = homefile(LESSKEYFILE);
557: if (filename == NULL)
558: return;
559: if (lesskey(filename) < 0)
560: {
561: parg.p_string = filename;
562: error("Cannot use lesskey file \"%s\"", &parg);
563: }
564: free(filename);
565: }
566: #endif
567:
568: /*
569: * See if a char is a special line-editing command.
570: */
571: public int
572: editchar(c, flags)
573: int c;
574: int flags;
575: {
576: int action;
577: int nch;
578: char *s;
579: char usercmd[MAX_CMDLEN+1];
580:
581: /*
582: * An editing character could actually be a sequence of characters;
583: * for example, an escape sequence sent by pressing the uparrow key.
584: * To match the editing string, we use the command decoder
585: * but give it the edit-commands command table
586: * This table is constructed to match the user's keyboard.
587: */
588: if (c == erase_char)
589: return (EC_BACKSPACE);
590: if (c == kill_char)
591: return (EC_LINEKILL);
592:
593: /*
594: * Collect characters in a buffer.
595: * Start with the one we have, and get more if we need them.
596: */
597: nch = 0;
598: do {
599: if (nch > 0)
600: c = getcc();
601: usercmd[nch] = c;
602: usercmd[nch+1] = '\0';
603: nch++;
604: action = ecmd_decode(usercmd, &s);
605: } while (action == A_PREFIX);
606:
607: if (flags & EC_NOHISTORY)
608: {
609: /*
610: * The caller says there is no history list.
611: * Reject any history-manipulation action.
612: */
613: switch (action)
614: {
615: case EC_UP:
616: case EC_DOWN:
617: action = A_INVALID;
618: break;
619: }
620: }
621: if (flags & EC_NOCOMPLETE)
622: {
623: /*
624: * The caller says we don't want any filename completion cmds.
625: * Reject them.
626: */
627: switch (action)
628: {
629: case EC_F_COMPLETE:
630: case EC_B_COMPLETE:
631: case EC_EXPAND:
632: action = A_INVALID;
633: break;
634: }
635: }
636: if ((flags & EC_PEEK) || action == A_INVALID)
637: {
638: /*
639: * We're just peeking, or we didn't understand the command.
640: * Unget all the characters we read in the loop above.
641: * This does NOT include the original character that was
642: * passed in as a parameter.
643: */
644: while (nch > 1) {
645: ungetcc(usercmd[--nch]);
646: }
647: } else
648: {
649: if (s != NULL)
650: ungetsc(s);
651: }
652: return action;
653: }
654: