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 CONTROL('X'),CONTROL('X'),0, A_GOMARK,
146 ':','e',0, A_EXAMINE,
147 CONTROL('X'),CONTROL('V'),0, A_EXAMINE,
148 ':','n',0, A_NEXT_FILE,
149 ':','p',0, A_PREV_FILE,
152 ':','x',0, A_INDEX_FILE,
153 ':','d',0, A_REMOVE_FILE,
155 ':','t',0, A_OPT_TOGGLE|A_EXTRA, 't',0,
156 's',0, A_OPT_TOGGLE|A_EXTRA, 'o',0,
157 '_',0, A_DISP_OPTION,
174 static unsigned char edittable[] =
176 '\t',0, EC_F_COMPLETE, /* TAB */
177 '\17',0, EC_B_COMPLETE, /* BACKTAB */
178 SK(SK_BACKTAB),0, EC_B_COMPLETE, /* BACKTAB */
179 ESC,'\t',0, EC_B_COMPLETE, /* ESC TAB */
180 CONTROL('L'),0, EC_EXPAND, /* CTRL-L */
181 CONTROL('V'),0, EC_LITERAL, /* BACKSLASH */
182 CONTROL('A'),0, EC_LITERAL, /* BACKSLASH */
183 ESC,'l',0, EC_RIGHT, /* ESC l */
184 SK(SK_RIGHT_ARROW),0, EC_RIGHT, /* RIGHTARROW */
185 ESC,'h',0, EC_LEFT, /* ESC h */
186 SK(SK_LEFT_ARROW),0, EC_LEFT, /* LEFTARROW */
187 ESC,'b',0, EC_W_LEFT, /* ESC b */
188 ESC,SK(SK_LEFT_ARROW),0, EC_W_LEFT, /* ESC LEFTARROW */
189 SK(SK_CTL_LEFT_ARROW),0, EC_W_LEFT, /* CTRL-LEFTARROW */
190 ESC,'w',0, EC_W_RIGHT, /* ESC w */
191 ESC,SK(SK_RIGHT_ARROW),0, EC_W_RIGHT, /* ESC RIGHTARROW */
192 SK(SK_CTL_RIGHT_ARROW),0, EC_W_RIGHT, /* CTRL-RIGHTARROW */
193 ESC,'i',0, EC_INSERT, /* ESC i */
194 SK(SK_INSERT),0, EC_INSERT, /* INSERT */
195 ESC,'x',0, EC_DELETE, /* ESC x */
196 SK(SK_DELETE),0, EC_DELETE, /* DELETE */
197 ESC,'X',0, EC_W_DELETE, /* ESC X */
198 ESC,SK(SK_DELETE),0, EC_W_DELETE, /* ESC DELETE */
199 SK(SK_CTL_DELETE),0, EC_W_DELETE, /* CTRL-DELETE */
200 SK(SK_CTL_BACKSPACE),0, EC_W_BACKSPACE, /* CTRL-BACKSPACE */
201 ESC,'\b',0, EC_W_BACKSPACE, /* ESC BACKSPACE */
202 ESC,'0',0, EC_HOME, /* ESC 0 */
203 SK(SK_HOME),0, EC_HOME, /* HOME */
204 ESC,'$',0, EC_END, /* ESC $ */
205 SK(SK_END),0, EC_END, /* END */
206 ESC,'k',0, EC_UP, /* ESC k */
207 SK(SK_UP_ARROW),0, EC_UP, /* UPARROW */
208 ESC,'j',0, EC_DOWN, /* ESC j */
209 SK(SK_DOWN_ARROW),0, EC_DOWN, /* DOWNARROW */
210 CONTROL('G'),0, EC_ABORT, /* CTRL-G */
214 * Structure to support a list of command tables.
218 struct tablelist *t_next;
224 * List of command tables and list of line-edit tables.
226 static struct tablelist *list_fcmd_tables = NULL;
227 static struct tablelist *list_ecmd_tables = NULL;
228 static struct tablelist *list_var_tables = NULL;
229 static struct tablelist *list_sysvar_tables = NULL;
233 * Expand special key abbreviations in a command table.
236 expand_special_keys(table, len)
246 for (fm = table; fm < table + len; )
249 * Rewrite each command in the table with any
250 * special key abbreviations expanded.
252 for (to = fm; *fm != '\0'; )
254 if (*fm != SK_SPECIAL_KEY)
260 * After SK_SPECIAL_KEY, next byte is the type
261 * of special key (one of the SK_* contants),
262 * and the byte after that is the number of bytes,
263 * N, reserved by the abbreviation (including the
264 * SK_SPECIAL_KEY and key type bytes).
265 * Replace all N bytes with the actual bytes
266 * output by the special key on this terminal.
268 repl = special_key_str(fm[1]);
271 if (repl == NULL || (int) strlen(repl) > klen)
273 while (*repl != '\0')
278 * Fill any unused bytes between end of command and
279 * the action byte with A_SKIP.
287 while (*fm++ != '\0')
294 * Initialize the command lists.
300 * Add the default command tables.
302 add_fcmd_table((char*)cmdtable, sizeof(cmdtable));
303 add_ecmd_table((char*)edittable, sizeof(edittable));
306 * For backwards compatibility,
307 * try to add tables in the OLD system lesskey file.
310 add_hometable(NULL, BINDIR "/.sysless", 1);
313 * Try to add the tables in the system lesskey file.
315 add_hometable("LESSKEY_SYSTEM", LESSKEYFILE_SYS, 1);
317 * Try to add the tables in the standard lesskey file "$HOME/.less".
319 add_hometable("LESSKEY", LESSKEYFILE, 0);
324 * Add a command table.
327 add_cmd_table(tlist, buf, len)
328 struct tablelist **tlist;
337 * Allocate a tablelist structure, initialize it,
338 * and link it into the list of tables.
340 if ((t = (struct tablelist *)
341 calloc(1, sizeof(struct tablelist))) == NULL)
345 expand_special_keys(buf, len);
347 t->t_end = buf + len;
354 * Add a command table.
357 add_fcmd_table(buf, len)
361 if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
362 error("Warning: some commands disabled", NULL_PARG);
366 * Add an editing command table.
369 add_ecmd_table(buf, len)
373 if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
374 error("Warning: some edit commands disabled", NULL_PARG);
378 * Add an environment variable table.
381 add_var_table(tlist, buf, len)
382 struct tablelist **tlist;
386 if (add_cmd_table(tlist, buf, len) < 0)
387 error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
391 * Search a single command table for the command string in cmd.
394 cmd_search(cmd, table, endtable, sp)
405 for (p = table, q = cmd; p < endtable; p++, q++)
410 * Current characters match.
411 * If we're at the end of the string, we've found it.
412 * Return the action code, which is the character
413 * after the null at the end of the string
414 * in the command table.
424 * We get here only if the original
425 * cmd string passed in was empty ("").
426 * I don't think that can happen,
427 * but just in case ...
432 * Check for an "extra" string.
441 } else if (*q == '\0')
444 * Hit the end of the user's command,
445 * but not the end of the string in the command table.
446 * The user's command is incomplete.
453 * Skip ahead to the next command in the
454 * command table, and reset the pointer
455 * to the beginning of the user's command.
457 if (*p == '\0' && p[1] == A_END_LIST)
460 * A_END_LIST is a special marker that tells
461 * us to abort the cmd search.
476 * No match found in the entire command table.
482 * Decode a command character and return the associated action.
483 * The "extra" string, if any, is returned in sp.
486 cmd_decode(tlist, cmd, sp)
487 struct tablelist *tlist;
492 int action = A_INVALID;
495 * Search thru all the command tables.
496 * Stop when we find an action which is not A_INVALID.
498 for (t = tlist; t != NULL; t = t->t_next)
500 action = cmd_search(cmd, t->t_start, t->t_end, sp);
501 if (action != A_INVALID)
504 if (action == A_UINVALID)
510 * Decode a command from the cmdtables list.
517 return (cmd_decode(list_fcmd_tables, cmd, sp));
521 * Decode a command from the edittables list.
528 return (cmd_decode(list_ecmd_tables, cmd, sp));
532 * Get the value of an environment variable.
533 * Looks first in the lesskey file, then in the real environment.
542 a = cmd_decode(list_var_tables, var, &s);
546 if (s != NULL && *s != '\0')
548 a = cmd_decode(list_sysvar_tables, var, &s);
556 * Get an "integer" from a lesskey file.
557 * Integers are stored in a funny format:
558 * two bytes, low order first, in radix KRADIX.
567 n += *(*sp)++ * KRADIX;
572 * Process an old (pre-v241) lesskey file.
575 old_lesskey(buf, len)
580 * Old-style lesskey file.
581 * The file must end with either
583 * or ...,cmd,0,action|A_EXTRA,string,0
584 * So the last byte or the second to last byte must be zero.
586 if (buf[len-1] != '\0' && buf[len-2] != '\0')
588 add_fcmd_table(buf, len);
593 * Process a new (post-v241) lesskey file.
596 new_lesskey(buf, len, sysvar)
606 * New-style lesskey file.
607 * Extract the pieces.
609 if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
610 buf[len-2] != C1_END_LESSKEY_MAGIC ||
611 buf[len-1] != C2_END_LESSKEY_MAGIC)
621 add_fcmd_table(p, n);
626 add_ecmd_table(p, n);
631 add_var_table((sysvar) ?
632 &list_sysvar_tables : &list_var_tables, p, n);
639 * Unrecognized section type.
647 * Set up a user command table, based on a "lesskey" file.
650 lesskey(filename, sysvar)
662 * Try to open the lesskey file.
664 filename = shell_unquote(filename);
665 f = open(filename, OPEN_READ);
671 * Read the file into a buffer.
672 * We first figure out the size of the file and allocate space for it.
673 * {{ Minimal error checking is done here.
674 * A garbage .less file will produce strange results.
675 * To avoid a large amount of error checking code here, we
676 * rely on the lesskey program to generate a good .less file. }}
679 if (len == NULL_POSITION || len < 3)
682 * Bad file (valid file must have at least 3 chars).
687 if ((buf = (char *) calloc((int)len, sizeof(char))) == NULL)
692 if (lseek(f, (off_t)0, SEEK_SET) == BAD_LSEEK)
698 n = read(f, buf, (unsigned int) len);
707 * Figure out if this is an old-style (before version 241)
708 * or new-style lesskey file format.
710 if (buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
711 buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
712 return (old_lesskey(buf, (int)len));
713 return (new_lesskey(buf, (int)len, sysvar));
717 * Add the standard lesskey file "$HOME/.less"
720 add_hometable(envname, def_filename, sysvar)
728 if (envname != NULL && (filename = lgetenv(envname)) != NULL)
729 filename = save(filename);
731 filename = save(def_filename);
733 filename = homefile(def_filename);
734 if (filename == NULL)
736 if (lesskey(filename, sysvar) < 0)
738 parg.p_string = filename;
739 error("Cannot use lesskey file \"%s\"", &parg);
746 * See if a char is a special line-editing command.
756 char usercmd[MAX_CMDLEN+1];
759 * An editing character could actually be a sequence of characters;
760 * for example, an escape sequence sent by pressing the uparrow key.
761 * To match the editing string, we use the command decoder
762 * but give it the edit-commands command table
763 * This table is constructed to match the user's keyboard.
765 if (c == erase_char || c == erase2_char)
766 return (EC_BACKSPACE);
768 return (EC_LINEKILL);
771 * Collect characters in a buffer.
772 * Start with the one we have, and get more if we need them.
779 usercmd[nch+1] = '\0';
781 action = ecmd_decode(usercmd, &s);
782 } while (action == A_PREFIX);
784 if (flags & EC_NORIGHTLEFT)
795 if (flags & EC_NOHISTORY)
798 * The caller says there is no history list.
799 * Reject any history-manipulation action.
810 #if TAB_COMPLETE_FILENAME
811 if (flags & EC_NOCOMPLETE)
814 * The caller says we don't want any filename completion cmds.
827 if ((flags & EC_PEEK) || action == A_INVALID)
830 * We're just peeking, or we didn't understand the command.
831 * Unget all the characters we read in the loop above.
832 * This does NOT include the original character that was
833 * passed in as a parameter.
837 ungetcc(usercmd[--nch]);