2 * Copyright (C) 1984-2017 Mark Nudelman
4 * You may distribute under the terms of either the GNU General Public
5 * License or the Less License, as specified in the README file.
7 * For more information, see the README file.
12 * Routines to decode user commands.
14 * This is all table driven.
15 * A command table is a sequence of command descriptors.
16 * Each command descriptor is a sequence of bytes with the following format:
17 * <c1><c2>...<cN><0><action>
18 * The characters c1,c2,...,cN are the command string; that is,
19 * the characters which the user must type.
20 * It is terminated by a null <0> byte.
21 * The byte after the null byte is the action code associated
22 * with the command string.
23 * If an action byte is OR-ed with A_EXTRA, this indicates
24 * that the option byte is followed by an extra string.
26 * There may be many command tables.
27 * The first (default) table is built-in.
28 * Other tables are read in from "lesskey" files.
29 * All the tables are linked together and are searched in order.
36 extern int erase_char, erase2_char, kill_char;
40 SK_SPECIAL_KEY, (k), 6, 1, 1, 1
42 * Command table is ordered roughly according to expected
43 * frequency of use, so the common commands are near the beginning.
46 static unsigned char cmdtable[] =
52 SK(SK_DOWN_ARROW),0, A_F_LINE,
53 CONTROL('E'),0, A_F_LINE,
54 CONTROL('N'),0, A_F_LINE,
57 CONTROL('Y'),0, A_B_LINE,
58 SK(SK_CONTROL_K),0, A_B_LINE,
59 CONTROL('P'),0, A_B_LINE,
60 SK(SK_UP_ARROW),0, A_B_LINE,
65 CONTROL('D'),0, A_F_SCROLL,
67 CONTROL('U'),0, A_B_SCROLL,
70 CONTROL('F'),0, A_F_SCREEN,
71 CONTROL('V'),0, A_F_SCREEN,
72 SK(SK_PAGE_DOWN),0, A_F_SCREEN,
74 CONTROL('B'),0, A_B_SCREEN,
75 ESC,'v',0, A_B_SCREEN,
76 SK(SK_PAGE_UP),0, A_B_SCREEN,
79 ESC,' ',0, A_FF_SCREEN,
81 ESC,'F',0, A_F_UNTIL_HILITE,
84 CONTROL('R'),0, A_REPAINT,
85 CONTROL('L'),0, A_REPAINT,
86 ESC,'u',0, A_UNDO_SEARCH,
88 SK(SK_HOME),0, A_GOLINE,
99 SK(SK_RIGHT_ARROW),0, A_RSHIFT,
100 SK(SK_LEFT_ARROW),0, A_LSHIFT,
101 SK(SK_CTL_RIGHT_ARROW),0, A_RRSHIFT,
102 SK(SK_CTL_LEFT_ARROW),0, A_LLSHIFT,
103 '{',0, A_F_BRACKET|A_EXTRA, '{','}',0,
104 '}',0, A_B_BRACKET|A_EXTRA, '{','}',0,
105 '(',0, A_F_BRACKET|A_EXTRA, '(',')',0,
106 ')',0, A_B_BRACKET|A_EXTRA, '(',')',0,
107 '[',0, A_F_BRACKET|A_EXTRA, '[',']',0,
108 ']',0, A_B_BRACKET|A_EXTRA, '[',']',0,
109 ESC,CONTROL('F'),0, A_F_BRACKET,
110 ESC,CONTROL('B'),0, A_B_BRACKET,
112 ESC,'G',0, A_GOEND_BUF,
115 SK(SK_END),0, A_GOEND,
131 CONTROL('G'),0, A_STAT,
135 ESC,'/',0, A_F_SEARCH|A_EXTRA, '*',0,
136 ESC,'?',0, A_B_SEARCH|A_EXTRA, '*',0,
137 'n',0, A_AGAIN_SEARCH,
138 ESC,'n',0, A_T_AGAIN_SEARCH,
139 'N',0, A_REVERSE_SEARCH,
140 ESC,'N',0, A_T_REVERSE_SEARCH,
144 ESC,'m',0, A_CLRMARK,
146 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
148 ':','e',0, A_EXAMINE,
149 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
150 ':','n',0, A_NEXT_FILE,
151 ':','p',0, A_PREV_FILE,
154 ':','x',0, A_INDEX_FILE,
155 ':','d',0, A_REMOVE_FILE,
157 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
158 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
159 '_',0, A_DISP_OPTION,
176 static unsigned char edittable[] =
178 '\t',0, EC_F_COMPLETE, /* TAB */
179 '\17',0, EC_B_COMPLETE, /* BACKTAB */
180 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
181 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
182 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
183 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
184 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
185 ESC,'l',0, EC_RIGHT, /* ESC l */
186 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
187 ESC,'h',0, EC_LEFT, /* ESC h */
188 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
189 ESC,'b',0, EC_W_LEFT, /* ESC b */
190 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
191 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
192 ESC,'w',0, EC_W_RIGHT, /* ESC w */
193 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
194 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
195 ESC,'i',0, EC_INSERT, /* ESC i */
196 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
197 ESC,'x',0, EC_DELETE, /* ESC x */
198 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
199 ESC,'X',0, EC_W_DELETE, /* ESC X */
200 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
201 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
202 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
203 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
204 ESC,'0',0, EC_HOME, /* ESC 0 */
205 SK(SK_HOME),0, EC_HOME, /* HOME */
206 ESC,'$',0, EC_END, /* ESC $ */
207 SK(SK_END),0, EC_END, /* END */
208 ESC,'k',0, EC_UP, /* ESC k */
209 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
210 ESC,'j',0, EC_DOWN, /* ESC j */
211 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
212 CONTROL('G'),0, EC_ABORT, /* CTRL-G */
216 * Structure to support a list of command tables.
220 struct tablelist *t_next;
226 * List of command tables and list of line-edit tables.
228 static struct tablelist *list_fcmd_tables = NULL;
229 static struct tablelist *list_ecmd_tables = NULL;
230 static struct tablelist *list_var_tables = NULL;
231 static struct tablelist *list_sysvar_tables = NULL;
235 * Expand special key abbreviations in a command table.
238 expand_special_keys(table, len)
248 for (fm = table; fm < table + len; )
251 * Rewrite each command in the table with any
252 * special key abbreviations expanded.
254 for (to = fm; *fm != '\0'; )
256 if (*fm != SK_SPECIAL_KEY)
262 * After SK_SPECIAL_KEY, next byte is the type
263 * of special key (one of the SK_* contants),
264 * and the byte after that is the number of bytes,
265 * N, reserved by the abbreviation (including the
266 * SK_SPECIAL_KEY and key type bytes).
267 * Replace all N bytes with the actual bytes
268 * output by the special key on this terminal.
270 repl = special_key_str(fm[1]);
273 if (repl == NULL || (int) strlen(repl) > klen)
275 while (*repl != '\0')
280 * Fill any unused bytes between end of command and
281 * the action byte with A_SKIP.
289 while (*fm++ != '\0')
296 * Expand special key abbreviations in a list of command tables.
299 expand_cmd_table(tlist)
300 struct tablelist *tlist;
303 for (t = tlist; t != NULL; t = t->t_next)
305 expand_special_keys(t->t_start, t->t_end - t->t_start);
310 * Expand special key abbreviations in all command tables.
315 expand_cmd_table(list_fcmd_tables);
316 expand_cmd_table(list_ecmd_tables);
317 expand_cmd_table(list_var_tables);
318 expand_cmd_table(list_sysvar_tables);
323 * Initialize the command lists.
329 * Add the default command tables.
331 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
332 add_ecmd_table((char*)edittable, sizeof(edittable));
335 * For backwards compatibility,
336 * try to add tables in the OLD system lesskey file.
339 add_hometable(NULL, BINDIR "/.sysless", 1);
342 * Try to add the tables in the system lesskey file.
344 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
346 * Try to add the tables in the standard lesskey file "$HOME/.less".
348 add_hometable("LESSKEY", LESSKEYFILE, 0);
353 * Add a command table.
356 add_cmd_table(tlist, buf, len)
357 struct tablelist **tlist;
366 * Allocate a tablelist structure, initialize it,
367 * and link it into the list of tables.
369 if ((t = (struct tablelist *)
370 calloc(1, sizeof(struct tablelist))) == NULL)
375 t->t_end = buf + len;
382 * Add a command table.
385 add_fcmd_table(buf, len)
389 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
390 error("Warning: some commands disabled", NULL_PARG);
394 * Add an editing command table.
397 add_ecmd_table(buf, len)
401 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
402 error("Warning: some edit commands disabled", NULL_PARG);
406 * Add an environment variable table.
409 add_var_table(tlist, buf, len)
410 struct tablelist **tlist;
414 if (add_cmd_table(tlist, buf, len) < 0)
415 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
419 * Search a single command table for the command string in cmd.
422 cmd_search(cmd, table, endtable, sp)
433 for (p = table, q = cmd; p < endtable; p++, q++)
438 * Current characters match.
439 * If we're at the end of the string, we've found it.
440 * Return the action code, which is the character
441 * after the null at the end of the string
442 * in the command table.
452 * We get here only if the original
453 * cmd string passed in was empty ("").
454 * I don't think that can happen,
455 * but just in case ...
460 * Check for an "extra" string.
469 } else if (*q == '\0')
472 * Hit the end of the user's command,
473 * but not the end of the string in the command table.
474 * The user's command is incomplete.
481 * Skip ahead to the next command in the
482 * command table, and reset the pointer
483 * to the beginning of the user's command.
485 if (*p == '\0' && p[1] == A_END_LIST)
488 * A_END_LIST is a special marker that tells
489 * us to abort the cmd search.
504 * No match found in the entire command table.
510 * Decode a command character and return the associated action.
511 * The "extra" string, if any, is returned in sp.
514 cmd_decode(tlist, cmd, sp)
515 struct tablelist *tlist;
520 int action = A_INVALID;
523 * Search thru all the command tables.
524 * Stop when we find an action which is not A_INVALID.
526 for (t = tlist; t != NULL; t = t->t_next)
528 action = cmd_search(cmd, t->t_start, t->t_end, sp);
529 if (action != A_INVALID)
532 if (action == A_UINVALID)
538 * Decode a command from the cmdtables list.
545 return (cmd_decode(list_fcmd_tables, cmd, sp));
549 * Decode a command from the edittables list.
556 return (cmd_decode(list_ecmd_tables, cmd, sp));
560 * Get the value of an environment variable.
561 * Looks first in the lesskey file, then in the real environment.
570 a = cmd_decode(list_var_tables, var, &s);
574 if (s != NULL && *s != '\0')
576 a = cmd_decode(list_sysvar_tables, var, &s);
584 * Get an "integer" from a lesskey file.
585 * Integers are stored in a funny format:
586 * two bytes, low order first, in radix KRADIX.
595 n += *(*sp)++ * KRADIX;
600 * Process an old (pre-v241) lesskey file.
603 old_lesskey(buf, len)
608 * Old-style lesskey file.
609 * The file must end with either
611 * or ...,cmd,0,action|A_EXTRA,string,0
612 * So the last byte or the second to last byte must be zero.
614 if (buf[len-1] != '\0' && buf[len-2] != '\0')
616 add_fcmd_table(buf, len);
621 * Process a new (post-v241) lesskey file.
624 new_lesskey(buf, len, sysvar)
634 * New-style lesskey file.
635 * Extract the pieces.
637 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
638 buf[len-2] != C1_END_LESSKEY_MAGIC ||
639 buf[len-1] != C2_END_LESSKEY_MAGIC)
649 add_fcmd_table(p, n);
654 add_ecmd_table(p, n);
659 add_var_table((sysvar) ?
660 &list_sysvar_tables : &list_var_tables, p, n);
667 * Unrecognized section type.
675 * Set up a user command table, based on a "lesskey" file.
678 lesskey(filename, sysvar)
690 * Try to open the lesskey file.
692 f = open(filename, OPEN_READ);
697 * Read the file into a buffer.
698 * We first figure out the size of the file and allocate space for it.
699 * {{ Minimal error checking is done here.
700 * A garbage .less file will produce strange results.
701 * To avoid a large amount of error checking code here, we
702 * rely on the lesskey program to generate a good .less file. }}
705 if (len == NULL_POSITION || len < 3)
708 * Bad file (valid file must have at least 3 chars).
713 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
718 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
724 n = read(f, buf, (unsigned int) len);
733 * Figure out if this is an old-style (before version 241)
734 * or new-style lesskey file format.
736 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
737 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
738 return (old_lesskey(buf, (int)len));
739 return (new_lesskey(buf, (int)len, sysvar));
743 * Add the standard lesskey file "$HOME/.less"
746 add_hometable(envname, def_filename, sysvar)
754 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
755 filename = save(filename);
757 filename = save(def_filename);
759 filename = homefile(def_filename);
760 if (filename == NULL)
762 if (lesskey(filename, sysvar) < 0)
764 parg.p_string = filename;
765 error("Cannot use lesskey file \"%s\"", &parg);
772 * See if a char is a special line-editing command.
782 char usercmd[MAX_CMDLEN+1];
785 * An editing character could actually be a sequence of characters;
786 * for example, an escape sequence sent by pressing the uparrow key.
787 * To match the editing string, we use the command decoder
788 * but give it the edit-commands command table
789 * This table is constructed to match the user's keyboard.
791 if (c == erase_char || c == erase2_char)
792 return (EC_BACKSPACE);
794 return (EC_LINEKILL);
797 * Collect characters in a buffer.
798 * Start with the one we have, and get more if we need them.
805 usercmd[nch+1] = '\0';
807 action = ecmd_decode(usercmd, &s);
808 } while (action == A_PREFIX);
810 if (flags & EC_NORIGHTLEFT)
821 if (flags & EC_NOHISTORY)
824 * The caller says there is no history list.
825 * Reject any history-manipulation action.
836 #if TAB_COMPLETE_FILENAME
837 if (flags & EC_NOCOMPLETE)
840 * The caller says we don't want any filename completion cmds.
853 if ((flags & EC_PEEK) || action == A_INVALID)
856 * We're just peeking, or we didn't understand the command.
857 * Unget all the characters we read in the loop above.
858 * This does NOT include the original character that was
859 * passed in as a parameter.
863 ungetcc(usercmd[--nch]);