xref: /dragonfly/contrib/less/decode.c (revision e0f238eda64c20d98364903e0c003825fd0b66dd)
1 /*
2  * Copyright (C) 1984-2024  Mark Nudelman
3  *
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.
6  *
7  * For more information, see the README file.
8  */
9 
10 
11 /*
12  * Routines to decode user commands.
13  *
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.
25  *
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.
30  */
31 
32 #include "less.h"
33 #include "cmd.h"
34 #include "lesskey.h"
35 
36 extern int erase_char, erase2_char, kill_char;
37 extern int mousecap;
38 extern int sc_height;
39 
40 /* "content" is lesskey source, never binary. */
41 static void add_content_table(int (*call_lesskey)(constant char *, lbool), constant char *envname, lbool sysvar);
42 static int add_hometable(int (*call_lesskey)(constant char *, lbool), constant char *envname, constant char *def_filename, lbool sysvar);
43 
44 #define SK(k) \
45           SK_SPECIAL_KEY, (k), 6, 1, 1, 1
46 /*
47  * Command table is ordered roughly according to expected
48  * frequency of use, so the common commands are near the beginning.
49  */
50 
51 static unsigned char cmdtable[] =
52 {
53           '\r',0,                         A_F_LINE,
54           '\n',0,                         A_F_LINE,
55           'e',0,                          A_F_LINE,
56           'j',0,                          A_F_LINE,
57           SK(SK_DOWN_ARROW),0,            A_F_LINE,
58           CONTROL('E'),0,                 A_F_LINE,
59           CONTROL('N'),0,                 A_F_LINE,
60           'k',0,                          A_B_LINE,
61           'y',0,                          A_B_LINE,
62           CONTROL('Y'),0,                 A_B_LINE,
63           SK(SK_CONTROL_K),0,             A_B_LINE,
64           CONTROL('P'),0,                 A_B_LINE,
65           SK(SK_UP_ARROW),0,              A_B_LINE,
66           'J',0,                          A_FF_LINE,
67           'K',0,                          A_BF_LINE,
68           'Y',0,                          A_BF_LINE,
69           'd',0,                          A_F_SCROLL,
70           CONTROL('D'),0,                 A_F_SCROLL,
71           'u',0,                          A_B_SCROLL,
72           CONTROL('U'),0,                 A_B_SCROLL,
73           ESC,'[','M',0,                  A_X11MOUSE_IN,
74           ESC,'[','<',0,                  A_X116MOUSE_IN,
75           ' ',0,                          A_F_SCREEN,
76           'f',0,                          A_F_SCREEN,
77           CONTROL('F'),0,                 A_F_SCREEN,
78           CONTROL('V'),0,                 A_F_SCREEN,
79           SK(SK_PAGE_DOWN),0,             A_F_SCREEN,
80           'b',0,                          A_B_SCREEN,
81           CONTROL('B'),0,                 A_B_SCREEN,
82           ESC,'v',0,                      A_B_SCREEN,
83           SK(SK_PAGE_UP),0,               A_B_SCREEN,
84           'z',0,                          A_F_WINDOW,
85           'w',0,                          A_B_WINDOW,
86           ESC,' ',0,                      A_FF_SCREEN,
87           'F',0,                          A_F_FOREVER,
88           ESC,'F',0,                      A_F_UNTIL_HILITE,
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           ESC,'U',0,                      A_CLR_SEARCH,
95           'g',0,                          A_GOLINE,
96           SK(SK_HOME),0,                  A_GOLINE,
97           '<',0,                          A_GOLINE,
98           ESC,'<',0,                      A_GOLINE,
99           'p',0,                          A_PERCENT,
100           '%',0,                          A_PERCENT,
101           ESC,'(',0,                      A_LSHIFT,
102           ESC,')',0,                      A_RSHIFT,
103           ESC,'{',0,                      A_LLSHIFT,
104           ESC,'}',0,                      A_RRSHIFT,
105           SK(SK_RIGHT_ARROW),0,           A_RSHIFT,
106           SK(SK_LEFT_ARROW),0,            A_LSHIFT,
107           SK(SK_CTL_RIGHT_ARROW),0,       A_RRSHIFT,
108           SK(SK_CTL_LEFT_ARROW),0,        A_LLSHIFT,
109           '{',0,                          A_F_BRACKET|A_EXTRA,        '{','}',0,
110           '}',0,                          A_B_BRACKET|A_EXTRA,        '{','}',0,
111           '(',0,                          A_F_BRACKET|A_EXTRA,        '(',')',0,
112           ')',0,                          A_B_BRACKET|A_EXTRA,        '(',')',0,
113           '[',0,                          A_F_BRACKET|A_EXTRA,        '[',']',0,
114           ']',0,                          A_B_BRACKET|A_EXTRA,        '[',']',0,
115           ESC,CONTROL('F'),0,             A_F_BRACKET,
116           ESC,CONTROL('B'),0,             A_B_BRACKET,
117           'G',0,                          A_GOEND,
118           ESC,'G',0,                      A_GOEND_BUF,
119           ESC,'>',0,                      A_GOEND,
120           '>',0,                          A_GOEND,
121           SK(SK_END),0,                   A_GOEND,
122           'P',0,                          A_GOPOS,
123 
124           '0',0,                          A_DIGIT,
125           '1',0,                          A_DIGIT,
126           '2',0,                          A_DIGIT,
127           '3',0,                          A_DIGIT,
128           '4',0,                          A_DIGIT,
129           '5',0,                          A_DIGIT,
130           '6',0,                          A_DIGIT,
131           '7',0,                          A_DIGIT,
132           '8',0,                          A_DIGIT,
133           '9',0,                          A_DIGIT,
134           '.',0,                          A_DIGIT,
135 
136           '=',0,                          A_STAT,
137           CONTROL('G'),0,                 A_STAT,
138           ':','f',0,                      A_STAT,
139           '/',0,                          A_F_SEARCH,
140           '?',0,                          A_B_SEARCH,
141           ESC,'/',0,                      A_F_SEARCH|A_EXTRA,        '*',0,
142           ESC,'?',0,                      A_B_SEARCH|A_EXTRA,        '*',0,
143           'n',0,                          A_AGAIN_SEARCH,
144           ESC,'n',0,                      A_T_AGAIN_SEARCH,
145           'N',0,                          A_REVERSE_SEARCH,
146           ESC,'N',0,                      A_T_REVERSE_SEARCH,
147           '&',0,                          A_FILTER,
148           'm',0,                          A_SETMARK,
149           'M',0,                          A_SETMARKBOT,
150           ESC,'m',0,                      A_CLRMARK,
151           '\'',0,                         A_GOMARK,
152           CONTROL('X'),CONTROL('X'),0,    A_GOMARK,
153           'E',0,                          A_EXAMINE,
154           ':','e',0,                      A_EXAMINE,
155           CONTROL('X'),CONTROL('V'),0,    A_EXAMINE,
156           ':','n',0,                      A_NEXT_FILE,
157           ':','p',0,                      A_PREV_FILE,
158           CONTROL('O'),CONTROL('N'),0,    A_OSC8_F_SEARCH,
159           CONTROL('O'),'n',0,             A_OSC8_F_SEARCH,
160           CONTROL('O'),CONTROL('P'),0,    A_OSC8_B_SEARCH,
161           CONTROL('O'),'p',0,             A_OSC8_B_SEARCH,
162           CONTROL('O'),CONTROL('O'),0,    A_OSC8_OPEN,
163           CONTROL('O'),'o',0,             A_OSC8_OPEN,
164           CONTROL('O'),CONTROL('L'),0,    A_OSC8_JUMP,
165           CONTROL('O'),'l',0,             A_OSC8_JUMP,
166           't',0,                          A_NEXT_TAG,
167           'T',0,                          A_PREV_TAG,
168           ':','x',0,                      A_INDEX_FILE,
169           ':','d',0,                      A_REMOVE_FILE,
170           '-',0,                          A_OPT_TOGGLE,
171           ':','t',0,                      A_OPT_TOGGLE|A_EXTRA,        't',0,
172           's',0,                          A_OPT_TOGGLE|A_EXTRA,        'o',0,
173           '_',0,                          A_DISP_OPTION,
174           '|',0,                          A_PIPE,
175           'v',0,                          A_VISUAL,
176           '!',0,                          A_SHELL,
177           '#',0,                          A_PSHELL,
178           '+',0,                          A_FIRSTCMD,
179 
180           'H',0,                          A_HELP,
181           'h',0,                          A_HELP,
182           SK(SK_F1),0,                    A_HELP,
183           'V',0,                          A_VERSION,
184           'q',0,                          A_QUIT,
185           'Q',0,                          A_QUIT,
186           ':','q',0,                      A_QUIT,
187           ':','Q',0,                      A_QUIT,
188           'Z','Z',0,                      A_QUIT
189 };
190 
191 static unsigned char edittable[] =
192 {
193           '\t',0,                         EC_F_COMPLETE,  /* TAB */
194           '\17',0,                        EC_B_COMPLETE,  /* BACKTAB */
195           SK(SK_BACKTAB),0,               EC_B_COMPLETE,  /* BACKTAB */
196           ESC,'\t',0,                     EC_B_COMPLETE,  /* ESC TAB */
197           CONTROL('L'),0,                 EC_EXPAND,      /* CTRL-L */
198           CONTROL('V'),0,                 EC_LITERAL,     /* BACKSLASH */
199           CONTROL('A'),0,                 EC_LITERAL,     /* BACKSLASH */
200           ESC,'l',0,                      EC_RIGHT,       /* ESC l */
201           SK(SK_RIGHT_ARROW),0,           EC_RIGHT,       /* RIGHTARROW */
202           ESC,'h',0,                      EC_LEFT,        /* ESC h */
203           SK(SK_LEFT_ARROW),0,            EC_LEFT,        /* LEFTARROW */
204           ESC,'b',0,                      EC_W_LEFT,      /* ESC b */
205           ESC,SK(SK_LEFT_ARROW),0,        EC_W_LEFT,      /* ESC LEFTARROW */
206           SK(SK_CTL_LEFT_ARROW),0,        EC_W_LEFT,      /* CTRL-LEFTARROW */
207           ESC,'w',0,                      EC_W_RIGHT,     /* ESC w */
208           ESC,SK(SK_RIGHT_ARROW),0,       EC_W_RIGHT,     /* ESC RIGHTARROW */
209           SK(SK_CTL_RIGHT_ARROW),0,       EC_W_RIGHT,     /* CTRL-RIGHTARROW */
210           ESC,'i',0,                      EC_INSERT,      /* ESC i */
211           SK(SK_INSERT),0,                EC_INSERT,      /* INSERT */
212           ESC,'x',0,                      EC_DELETE,      /* ESC x */
213           SK(SK_DELETE),0,                EC_DELETE,      /* DELETE */
214           ESC,'X',0,                      EC_W_DELETE,    /* ESC X */
215           ESC,SK(SK_DELETE),0,            EC_W_DELETE,    /* ESC DELETE */
216           SK(SK_CTL_DELETE),0,            EC_W_DELETE,    /* CTRL-DELETE */
217           SK(SK_CTL_BACKSPACE),0,         EC_W_BACKSPACE, /* CTRL-BACKSPACE */
218           ESC,SK(SK_BACKSPACE),0,         EC_W_BACKSPACE, /* ESC BACKSPACE */
219           ESC,'0',0,                      EC_HOME,        /* ESC 0 */
220           SK(SK_HOME),0,                  EC_HOME,        /* HOME */
221           ESC,'$',0,                      EC_END,         /* ESC $ */
222           SK(SK_END),0,                   EC_END,         /* END */
223           ESC,'k',0,                      EC_UP,          /* ESC k */
224           SK(SK_UP_ARROW),0,              EC_UP,          /* UPARROW */
225           ESC,'j',0,                      EC_DOWN,        /* ESC j */
226           SK(SK_DOWN_ARROW),0,            EC_DOWN,        /* DOWNARROW */
227           CONTROL('G'),0,                 EC_ABORT,       /* CTRL-G */
228           ESC,'[','M',0,                  EC_X11MOUSE,    /* X11 mouse report */
229           ESC,'[','<',0,                  EC_X116MOUSE,   /* X11 1006 mouse report */
230 };
231 
232 static unsigned char dflt_vartable[] =
233 {
234           'L','E','S','S','_','O','S','C','8','_','m','a','n', 0, EV_OK|A_EXTRA,
235                     /* echo '%o' | sed -e "s,^man\:\\([^(]*\\)( *\\([^)]*\\)\.*,-man '\\2' '\\1'," -e"t X" -e"s,\.*,-echo Invalid man link," -e"\: X" */
236                     'e','c','h','o',' ','\'','%','o','\'',' ','|',' ','s','e','d',' ','-','e',' ','"','s',',','^','m','a','n','\\',':','\\','\\','(','[','^','(',']','*','\\','\\',')','(',' ','*','\\','\\','(','[','^',')',']','*','\\','\\',')','\\','.','*',',','-','m','a','n',' ','\'','\\','\\','2','\'',' ','\'','\\','\\','1','\'',',','"',' ','-','e','"','t',' ','X','"',' ','-','e','"','s',',','\\','.','*',',','-','e','c','h','o',' ','I','n','v','a','l','i','d',' ','m','a','n',' ','l','i','n','k',',','"',' ','-','e','"','\\',':',' ','X','"',
237                     0,
238 
239           'L','E','S','S','_','O','S','C','8','_','f','i','l','e', 0, EV_OK|A_EXTRA,
240                     /* eval `echo '%o' | sed -e "s,^file://\\([^/]*\\)\\(.*\\),_H=\\1;_P=\\2;_E=0," -e"t X" -e"s,.*,_E=1," -e": X"`; if [ "$_E" = 1 ]; then echo -echo Invalid file link; elif [ -z "$_H" -o "$_H" = localhost -o "$_H" = $HOSTNAME ]; then echo ":e $_P"; else echo -echo Cannot open remote file on "$_H"; fi */
241                     'e','v','a','l',' ','`','e','c','h','o',' ','\'','%','o','\'',' ','|',' ','s','e','d',' ','-','e',' ','"','s',',','^','f','i','l','e','\\',':','/','/','\\','\\','(','[','^','/',']','*','\\','\\',')','\\','\\','(','\\','.','*','\\','\\',')',',','_','H','=','\\','\\','1',';','_','P','=','\\','\\','2',';','_','E','=','0',',','"',' ','-','e','"','t',' ','X','"',' ','-','e','"','s',',','\\','.','*',',','_','E','=','1',',','"',' ','-','e','"','\\',':',' ','X','"','`',';',' ','i','f',' ','[',' ','"','$','_','E','"',' ','=',' ','1',' ',']',';',' ','t','h','e','n',' ','e','c','h','o',' ','-','e','c','h','o',' ','I','n','v','a','l','i','d',' ','f','i','l','e',' ','l','i','n','k',';',' ','e','l','i','f',' ','[',' ','-','z',' ','"','$','_','H','"',' ','-','o',' ','"','$','_','H','"',' ','=',' ','l','o','c','a','l','h','o','s','t',' ','-','o',' ','"','$','_','H','"',' ','=',' ','$','H','O','S','T','N','A','M','E',' ',']',';',' ','t','h','e','n',' ','e','c','h','o',' ','"','\\',':','e',' ','$','_','P','"',';',' ','e','l','s','e',' ','e','c','h','o',' ','-','e','c','h','o',' ','C','a','n','n','o','t',' ','o','p','e','n',' ','r','e','m','o','t','e',' ','f','i','l','e',' ','o','n',' ','"','$','_','H','"',';',' ','f','i',
242                     0,
243 };
244 
245 /*
246  * Structure to support a list of command tables.
247  */
248 struct tablelist
249 {
250           struct tablelist *t_next;
251           unsigned char *t_start;
252           unsigned char *t_end;
253 };
254 
255 /*
256  * List of command tables and list of line-edit tables.
257  */
258 static struct tablelist *list_fcmd_tables = NULL;
259 static struct tablelist *list_ecmd_tables = NULL;
260 static struct tablelist *list_var_tables = NULL;
261 static struct tablelist *list_sysvar_tables = NULL;
262 
263 
264 /*
265  * Expand special key abbreviations in a command table.
266  */
expand_special_keys(unsigned char * table,size_t len)267 static void expand_special_keys(unsigned char *table, size_t len)
268 {
269           unsigned char *fm;
270           unsigned char *to;
271           int a;
272           constant char *repl;
273           size_t klen;
274 
275           for (fm = table;  fm < table + len; )
276           {
277                     /*
278                      * Rewrite each command in the table with any
279                      * special key abbreviations expanded.
280                      */
281                     for (to = fm;  *fm != '\0'; )
282                     {
283                               if (*fm != SK_SPECIAL_KEY)
284                               {
285                                         *to++ = *fm++;
286                                         continue;
287                               }
288                               /*
289                                * After SK_SPECIAL_KEY, next byte is the type
290                                * of special key (one of the SK_* constants),
291                                * and the byte after that is the number of bytes,
292                                * N, reserved by the abbreviation (including the
293                                * SK_SPECIAL_KEY and key type bytes).
294                                * Replace all N bytes with the actual bytes
295                                * output by the special key on this terminal.
296                                */
297                               repl = special_key_str(fm[1]);
298                               klen = fm[2] & 0377;
299                               fm += klen;
300                               if (repl == NULL || strlen(repl) > klen)
301                                         repl = "\377";
302                               while (*repl != '\0')
303                                         *to++ = (unsigned char) *repl++; /*{{type-issue}}*/
304                     }
305                     *to++ = '\0';
306                     /*
307                      * Fill any unused bytes between end of command and
308                      * the action byte with A_SKIP.
309                      */
310                     while (to <= fm)
311                               *to++ = A_SKIP;
312                     fm++;
313                     a = *fm++ & 0377;
314                     if (a & A_EXTRA)
315                     {
316                               while (*fm++ != '\0')
317                                         continue;
318                     }
319           }
320 }
321 
322 /*
323  * Expand special key abbreviations in a list of command tables.
324  */
expand_cmd_table(struct tablelist * tlist)325 static void expand_cmd_table(struct tablelist *tlist)
326 {
327           struct tablelist *t;
328           for (t = tlist;  t != NULL;  t = t->t_next)
329           {
330                     expand_special_keys(t->t_start, ptr_diff(t->t_end, t->t_start));
331           }
332 }
333 
334 /*
335  * Expand special key abbreviations in all command tables.
336  */
expand_cmd_tables(void)337 public void expand_cmd_tables(void)
338 {
339           expand_cmd_table(list_fcmd_tables);
340           expand_cmd_table(list_ecmd_tables);
341           expand_cmd_table(list_var_tables);
342           expand_cmd_table(list_sysvar_tables);
343 }
344 
345 /*
346  * Initialize the command lists.
347  */
init_cmds(void)348 public void init_cmds(void)
349 {
350           /*
351            * Add the default command tables.
352            */
353           add_fcmd_table(cmdtable, sizeof(cmdtable));
354           add_ecmd_table(edittable, sizeof(edittable));
355           add_sysvar_table(dflt_vartable, sizeof(dflt_vartable));
356 #if USERFILE
357 #ifdef BINDIR /* For backwards compatibility */
358           /* Try to add tables in the OLD system lesskey file. */
359           add_hometable(lesskey, NULL, BINDIR "/.sysless", TRUE);
360 #endif
361           /*
362            * Try to load lesskey source file or binary file.
363            * If the source file succeeds, don't load binary file.
364            * The binary file is likely to have been generated from
365            * a (possibly out of date) copy of the src file,
366            * so loading it is at best redundant.
367            */
368           /*
369            * Try to add tables in system lesskey src file.
370            */
371 #if HAVE_LESSKEYSRC
372           if (add_hometable(lesskey_src, "LESSKEYIN_SYSTEM", LESSKEYINFILE_SYS, TRUE) != 0)
373 #endif
374           {
375                     /*
376                      * Try to add the tables in the system lesskey binary file.
377                      */
378                     add_hometable(lesskey, "LESSKEY_SYSTEM", LESSKEYFILE_SYS, TRUE);
379           }
380           /*
381            * Try to add tables in the lesskey src file "$HOME/.lesskey".
382            */
383 #if HAVE_LESSKEYSRC
384           if (add_hometable(lesskey_src, "LESSKEYIN", DEF_LESSKEYINFILE, FALSE) != 0)
385 #endif
386           {
387                     /*
388                      * Try to add the tables in the standard lesskey binary file "$HOME/.less".
389                      */
390                     add_hometable(lesskey, "LESSKEY", LESSKEYFILE, FALSE);
391           }
392 #endif
393 
394           add_content_table(lesskey_content, "LESSKEY_CONTENT_SYSTEM", TRUE);
395           add_content_table(lesskey_content, "LESSKEY_CONTENT", FALSE);
396 }
397 
398 /*
399  * Add a command table.
400  */
add_cmd_table(struct tablelist ** tlist,unsigned char * buf,size_t len)401 static int add_cmd_table(struct tablelist **tlist, unsigned char *buf, size_t len)
402 {
403           struct tablelist *t;
404 
405           if (len == 0)
406                     return (0);
407           /*
408            * Allocate a tablelist structure, initialize it,
409            * and link it into the list of tables.
410            */
411           if ((t = (struct tablelist *)
412                               calloc(1, sizeof(struct tablelist))) == NULL)
413           {
414                     return (-1);
415           }
416           t->t_start = buf;
417           t->t_end = buf + len;
418           t->t_next = NULL;
419           if (*tlist == NULL)
420                     *tlist = t;
421           else
422           {
423                     struct tablelist *e;
424                     for (e = *tlist;  e->t_next != NULL;  e = e->t_next)
425                               continue;
426                     e->t_next = t;
427           }
428           return (0);
429 }
430 
431 /*
432  * Remove the last command table in a list.
433  */
pop_cmd_table(struct tablelist ** tlist)434 static void pop_cmd_table(struct tablelist **tlist)
435 {
436           struct tablelist *t;
437           if (*tlist == NULL)
438                     return;
439           if ((*tlist)->t_next == NULL)
440           {
441                     t = *tlist;
442                     *tlist = NULL;
443           } else
444           {
445                     struct tablelist *e;
446                     for (e = *tlist;  e->t_next->t_next != NULL;  e = e->t_next)
447                               continue;
448                     t = e->t_next;
449                     e->t_next = NULL;
450           }
451           free(t);
452 }
453 
454 /*
455  * Add a command table.
456  */
add_fcmd_table(unsigned char * buf,size_t len)457 public void add_fcmd_table(unsigned char *buf, size_t len)
458 {
459           if (add_cmd_table(&list_fcmd_tables, buf, len) < 0)
460                     error("Warning: some commands disabled", NULL_PARG);
461 }
462 
463 /*
464  * Add an editing command table.
465  */
add_ecmd_table(unsigned char * buf,size_t len)466 public void add_ecmd_table(unsigned char *buf, size_t len)
467 {
468           if (add_cmd_table(&list_ecmd_tables, buf, len) < 0)
469                     error("Warning: some edit commands disabled", NULL_PARG);
470 }
471 
472 /*
473  * Add an environment variable table.
474  */
add_var_table(struct tablelist ** tlist,unsigned char * buf,size_t len)475 static void add_var_table(struct tablelist **tlist, unsigned char *buf, size_t len)
476 {
477           struct xbuffer xbuf;
478 
479           xbuf_init(&xbuf);
480           expand_evars((char*)buf, len, &xbuf); /*{{unsigned-issue}}*/
481           /* {{ We leak the table in buf. expand_evars scribbled in it so it's useless anyway. }} */
482           if (add_cmd_table(tlist, xbuf.data, xbuf.end) < 0)
483                     error("Warning: environment variables from lesskey file unavailable", NULL_PARG);
484 }
485 
add_uvar_table(unsigned char * buf,size_t len)486 public void add_uvar_table(unsigned char *buf, size_t len)
487 {
488           add_var_table(&list_var_tables, buf, len);
489 }
490 
add_sysvar_table(unsigned char * buf,size_t len)491 public void add_sysvar_table(unsigned char *buf, size_t len)
492 {
493           add_var_table(&list_sysvar_tables, buf, len);
494 }
495 
496 /*
497  * Return action for a mouse wheel down event.
498  */
mouse_wheel_down(void)499 static int mouse_wheel_down(void)
500 {
501           return ((mousecap == OPT_ONPLUS) ? A_B_MOUSE : A_F_MOUSE);
502 }
503 
504 /*
505  * Return action for a mouse wheel up event.
506  */
mouse_wheel_up(void)507 static int mouse_wheel_up(void)
508 {
509           return ((mousecap == OPT_ONPLUS) ? A_F_MOUSE : A_B_MOUSE);
510 }
511 
512 /*
513  * Return action for the left mouse button trigger.
514  */
mouse_button_left(int x,int y)515 static int mouse_button_left(int x, int y)
516 {
517           /*
518            * {{ It would be better to return an action and then do this
519            *    in commands() but it's nontrivial to pass y to it. }}
520            */
521 #if OSC8_LINK
522           if (osc8_click(y, x))
523                     return (A_NOACTION);
524 #else
525           (void) x;
526 #endif /* OSC8_LINK */
527           if (y < sc_height-1)
528           {
529                     setmark('#', y);
530                     screen_trashed();
531           }
532           return (A_NOACTION);
533 }
534 
535 /*
536  * Return action for the right mouse button trigger.
537  */
mouse_button_right(int x,int y)538 static int mouse_button_right(int x, int y)
539 {
540           (void) x;
541           /*
542            * {{ unlike mouse_button_left, we could return an action,
543            *    but keep it near mouse_button_left for readability. }}
544            */
545           if (y < sc_height-1)
546           {
547                     gomark('#');
548                     screen_trashed();
549           }
550           return (A_NOACTION);
551 }
552 
553 /*
554  * Read a decimal integer. Return the integer and set *pterm to the terminating char.
555  */
getcc_int(char * pterm)556 static int getcc_int(char *pterm)
557 {
558           int num = 0;
559           int digits = 0;
560           for (;;)
561           {
562                     char ch = getcc();
563                     if (ch < '0' || ch > '9')
564                     {
565                               if (pterm != NULL) *pterm = ch;
566                               if (digits == 0)
567                                         return (-1);
568                               return (num);
569                     }
570                     if (ckd_mul(&num, num, 10) || ckd_add(&num, num, ch - '0'))
571                               return -1;
572                     ++digits;
573           }
574 }
575 
576 /*
577  * Read suffix of mouse input and return the action to take.
578  * The prefix ("\e[M") has already been read.
579  */
x11mouse_action(int skip)580 static int x11mouse_action(int skip)
581 {
582           static int prev_b = X11MOUSE_BUTTON_REL;
583           int b = getcc() - X11MOUSE_OFFSET;
584           int x = getcc() - X11MOUSE_OFFSET-1;
585           int y = getcc() - X11MOUSE_OFFSET-1;
586           if (skip)
587                     return (A_NOACTION);
588           switch (b) {
589           default:
590                     prev_b = b;
591                     return (A_NOACTION);
592           case X11MOUSE_WHEEL_DOWN:
593                     return mouse_wheel_down();
594           case X11MOUSE_WHEEL_UP:
595                     return mouse_wheel_up();
596           case X11MOUSE_BUTTON_REL:
597                     /* to trigger on button-up, we check the last button-down */
598                     switch (prev_b) {
599                     case X11MOUSE_BUTTON1:
600                               return mouse_button_left(x, y);
601                     /* is BUTTON2 the rightmost with 2-buttons mouse? */
602                     case X11MOUSE_BUTTON2:
603                     case X11MOUSE_BUTTON3:
604                               return mouse_button_right(x, y);
605                     }
606                     return (A_NOACTION);
607           }
608 }
609 
610 /*
611  * Read suffix of mouse input and return the action to take.
612  * The prefix ("\e[<") has already been read.
613  */
x116mouse_action(int skip)614 static int x116mouse_action(int skip)
615 {
616           char ch;
617           int x, y;
618           int b = getcc_int(&ch);
619           if (b < 0 || ch != ';') return (A_NOACTION);
620           x = getcc_int(&ch) - 1;
621           if (x < 0 || ch != ';') return (A_NOACTION);
622           y = getcc_int(&ch) - 1;
623           if (y < 0) return (A_NOACTION);
624           if (skip)
625                     return (A_NOACTION);
626           switch (b) {
627           case X11MOUSE_WHEEL_DOWN:
628                     return mouse_wheel_down();
629           case X11MOUSE_WHEEL_UP:
630                     return mouse_wheel_up();
631           case X11MOUSE_BUTTON1:
632                     if (ch != 'm') return (A_NOACTION);
633                     return mouse_button_left(x, y);
634           default:
635                     if (ch != 'm') return (A_NOACTION);
636                     /* any other button release */
637                     return mouse_button_right(x, y);
638           }
639 }
640 
641 /*
642  * Search a single command table for the command string in cmd.
643  */
cmd_search(constant char * cmd,constant char * table,constant char * endtable,constant char ** sp)644 static int cmd_search(constant char *cmd, constant char *table, constant char *endtable, constant char **sp)
645 {
646           constant char *p;
647           constant char *q;
648           int a = A_INVALID;
649 
650           *sp = NULL;
651           for (p = table, q = cmd;  p < endtable;  p++, q++)
652           {
653                     if (*p == *q)
654                     {
655                               /*
656                                * Current characters match.
657                                * If we're at the end of the string, we've found it.
658                                * Return the action code, which is the character
659                                * after the null at the end of the string
660                                * in the command table.
661                                */
662                               if (*p == '\0')
663                               {
664                                         a = *++p & 0377;
665                                         while (a == A_SKIP)
666                                                   a = *++p & 0377;
667                                         if (a == A_END_LIST)
668                                         {
669                                                   /*
670                                                    * We get here only if the original
671                                                    * cmd string passed in was empty ("").
672                                                    * I don't think that can happen,
673                                                    * but just in case ...
674                                                    */
675                                                   return (A_UINVALID);
676                                         }
677                                         /*
678                                          * Check for an "extra" string.
679                                          */
680                                         if (a & A_EXTRA)
681                                         {
682                                                   *sp = ++p;
683                                                   while (*p != '\0')
684                                                             ++p;
685                                                   a &= ~A_EXTRA;
686                                         }
687                                         if (a == A_X11MOUSE_IN)
688                                                   a = x11mouse_action(0);
689                                         else if (a == A_X116MOUSE_IN)
690                                                   a = x116mouse_action(0);
691                                         q = cmd-1;
692                               }
693                     } else if (*q == '\0')
694                     {
695                               /*
696                                * Hit the end of the user's command,
697                                * but not the end of the string in the command table.
698                                * The user's command is incomplete.
699                                */
700                               if (a == A_INVALID)
701                                         a = A_PREFIX;
702                               q = cmd-1;
703                     } else
704                     {
705                               /*
706                                * Not a match.
707                                * Skip ahead to the next command in the
708                                * command table, and reset the pointer
709                                * to the beginning of the user's command.
710                                */
711                               if (*p == '\0' && p[1] == A_END_LIST)
712                               {
713                                         /*
714                                          * A_END_LIST is a special marker that tells
715                                          * us to abort the cmd search.
716                                          */
717                                         return (A_UINVALID);
718                               }
719                               while (*p++ != '\0')
720                                         continue;
721                               while (*p == A_SKIP)
722                                         p++;
723                               if (*p & A_EXTRA)
724                                         while (*++p != '\0')
725                                                   continue;
726                               q = cmd-1;
727                     }
728           }
729           return (a);
730 }
731 
732 /*
733  * Decode a command character and return the associated action.
734  * The "extra" string, if any, is returned in sp.
735  */
cmd_decode(struct tablelist * tlist,constant char * cmd,constant char ** sp)736 static int cmd_decode(struct tablelist *tlist, constant char *cmd, constant char **sp)
737 {
738           struct tablelist *t;
739           int action = A_INVALID;
740 
741           /*
742            * Search for the cmd thru all the command tables.
743            * If we find it more than once, take the last one.
744            */
745           *sp = NULL;
746           for (t = tlist;  t != NULL;  t = t->t_next)
747           {
748                     constant char *tsp;
749                     int taction = cmd_search(cmd, (char *) t->t_start, (char *) t->t_end, &tsp);
750                     if (taction == A_UINVALID)
751                               taction = A_INVALID;
752                     if (taction != A_INVALID)
753                     {
754                               action = taction;
755                               *sp = tsp;
756                     }
757           }
758           return (action);
759 }
760 
761 /*
762  * Decode a command from the cmdtables list.
763  */
fcmd_decode(constant char * cmd,constant char ** sp)764 public int fcmd_decode(constant char *cmd, constant char **sp)
765 {
766           return (cmd_decode(list_fcmd_tables, cmd, sp));
767 }
768 
769 /*
770  * Decode a command from the edittables list.
771  */
ecmd_decode(constant char * cmd,constant char ** sp)772 public int ecmd_decode(constant char *cmd, constant char **sp)
773 {
774           return (cmd_decode(list_ecmd_tables, cmd, sp));
775 }
776 
777 /*
778  * Get the value of an environment variable.
779  * Looks first in the lesskey file, then in the real environment.
780  */
lgetenv(constant char * var)781 public constant char * lgetenv(constant char *var)
782 {
783           int a;
784           constant char *s;
785 
786           a = cmd_decode(list_var_tables, var, &s);
787           if (a == EV_OK)
788                     return (s);
789           s = getenv(var);
790           if (s != NULL && *s != '\0')
791                     return (s);
792           a = cmd_decode(list_sysvar_tables, var, &s);
793           if (a == EV_OK)
794                     return (s);
795           return (NULL);
796 }
797 
798 /*
799  * Like lgetenv, but also uses a buffer partially filled with an env table.
800  */
lgetenv_ext(constant char * var,unsigned char * env_buf,size_t env_buf_len)801 public constant char * lgetenv_ext(constant char *var, unsigned char *env_buf, size_t env_buf_len)
802 {
803           constant char *r;
804           size_t e;
805           size_t env_end = 0;
806 
807           for (e = 0;;)
808           {
809                     for (; e < env_buf_len; e++)
810                               if (env_buf[e] == '\0')
811                                         break;
812                     if (e >= env_buf_len) break;
813                     if (env_buf[++e] & A_EXTRA)
814                     {
815                               for (e = e+1; e < env_buf_len; e++)
816                                         if (env_buf[e] == '\0')
817                                                   break;
818                     }
819                     e++;
820                     if (e >= env_buf_len) break;
821                     env_end = e;
822           }
823           /* Temporarily add env_buf to var_tables, do the lookup, then remove it. */
824           add_uvar_table(env_buf, env_end);
825           r = lgetenv(var);
826           pop_cmd_table(&list_var_tables);
827           return r;
828 }
829 
830 /*
831  * Is a string null or empty?
832  */
isnullenv(constant char * s)833 public lbool isnullenv(constant char *s)
834 {
835           return (s == NULL || *s == '\0');
836 }
837 
838 #if USERFILE
839 /*
840  * Get an "integer" from a lesskey file.
841  * Integers are stored in a funny format:
842  * two bytes, low order first, in radix KRADIX.
843  */
gint(unsigned char ** sp)844 static size_t gint(unsigned char **sp)
845 {
846           size_t n;
847 
848           n = *(*sp)++;
849           n += *(*sp)++ * KRADIX;
850           return (n);
851 }
852 
853 /*
854  * Process an old (pre-v241) lesskey file.
855  */
old_lesskey(unsigned char * buf,size_t len)856 static int old_lesskey(unsigned char *buf, size_t len)
857 {
858           /*
859            * Old-style lesskey file.
860            * The file must end with either
861            *     ...,cmd,0,action
862            * or  ...,cmd,0,action|A_EXTRA,string,0
863            * So the last byte or the second to last byte must be zero.
864            */
865           if (buf[len-1] != '\0' && buf[len-2] != '\0')
866                     return (-1);
867           add_fcmd_table(buf, len);
868           return (0);
869 }
870 
871 /*
872  * Process a new (post-v241) lesskey file.
873  */
new_lesskey(unsigned char * buf,size_t len,lbool sysvar)874 static int new_lesskey(unsigned char *buf, size_t len, lbool sysvar)
875 {
876           unsigned char *p;
877           unsigned char *end;
878           int c;
879           size_t n;
880 
881           /*
882            * New-style lesskey file.
883            * Extract the pieces.
884            */
885           if (buf[len-3] != C0_END_LESSKEY_MAGIC ||
886               buf[len-2] != C1_END_LESSKEY_MAGIC ||
887               buf[len-1] != C2_END_LESSKEY_MAGIC)
888                     return (-1);
889           p = buf + 4;
890           end = buf + len;
891           for (;;)
892           {
893                     c = *p++;
894                     switch (c)
895                     {
896                     case CMD_SECTION:
897                               n = gint(&p);
898                               if (p+n >= end)
899                                         return (-1);
900                               add_fcmd_table(p, n);
901                               p += n;
902                               break;
903                     case EDIT_SECTION:
904                               n = gint(&p);
905                               if (p+n >= end)
906                                         return (-1);
907                               add_ecmd_table(p, n);
908                               p += n;
909                               break;
910                     case VAR_SECTION:
911                               n = gint(&p);
912                               if (p+n >= end)
913                                         return (-1);
914                               if (sysvar)
915                                         add_sysvar_table(p, n);
916                               else
917                                         add_uvar_table(p, n);
918                               p += n;
919                               break;
920                     case END_SECTION:
921                               return (0);
922                     default:
923                               /*
924                                * Unrecognized section type.
925                                */
926                               return (-1);
927                     }
928           }
929 }
930 
931 /*
932  * Set up a user command table, based on a "lesskey" file.
933  */
lesskey(constant char * filename,lbool sysvar)934 public int lesskey(constant char *filename, lbool sysvar)
935 {
936           unsigned char *buf;
937           POSITION len;
938           ssize_t n;
939           int f;
940 
941           if (!secure_allow(SF_LESSKEY))
942                     return (1);
943           /*
944            * Try to open the lesskey file.
945            */
946           f = open(filename, OPEN_READ);
947           if (f < 0)
948                     return (1);
949 
950           /*
951            * Read the file into a buffer.
952            * We first figure out the size of the file and allocate space for it.
953            * {{ Minimal error checking is done here.
954            *    A garbage .less file will produce strange results.
955            *    To avoid a large amount of error checking code here, we
956            *    rely on the lesskey program to generate a good .less file. }}
957            */
958           len = filesize(f);
959           if (len == NULL_POSITION || len < 3)
960           {
961                     /*
962                      * Bad file (valid file must have at least 3 chars).
963                      */
964                     close(f);
965                     return (-1);
966           }
967           if ((buf = (unsigned char *) calloc((size_t)len, sizeof(char))) == NULL)
968           {
969                     close(f);
970                     return (-1);
971           }
972           if (less_lseek(f, (less_off_t)0, SEEK_SET) == BAD_LSEEK)
973           {
974                     free(buf);
975                     close(f);
976                     return (-1);
977           }
978           n = read(f, buf, (size_t) len);
979           close(f);
980           if (n != len)
981           {
982                     free(buf);
983                     return (-1);
984           }
985 
986           /*
987            * Figure out if this is an old-style (before version 241)
988            * or new-style lesskey file format.
989            */
990           if (len < 4 ||
991               buf[0] != C0_LESSKEY_MAGIC || buf[1] != C1_LESSKEY_MAGIC ||
992               buf[2] != C2_LESSKEY_MAGIC || buf[3] != C3_LESSKEY_MAGIC)
993                     return (old_lesskey(buf, (size_t) len));
994           return (new_lesskey(buf, (size_t) len, sysvar));
995 }
996 
997 #if HAVE_LESSKEYSRC
lesskey_text(constant char * filename,lbool sysvar,lbool content)998 static int lesskey_text(constant char *filename, lbool sysvar, lbool content)
999 {
1000           static struct lesskey_tables tables;
1001           if (!secure_allow(SF_LESSKEY))
1002                     return (1);
1003           int r = content ? parse_lesskey_content(filename, &tables) : parse_lesskey(filename, &tables);
1004           if (r != 0)
1005                     return (r);
1006           add_fcmd_table(tables.cmdtable.buf.data, tables.cmdtable.buf.end);
1007           add_ecmd_table(tables.edittable.buf.data, tables.edittable.buf.end);
1008           if (sysvar)
1009                     add_sysvar_table(tables.vartable.buf.data, tables.vartable.buf.end);
1010           else
1011                     add_uvar_table(tables.vartable.buf.data, tables.vartable.buf.end);
1012           return (0);
1013 }
1014 
lesskey_src(constant char * filename,lbool sysvar)1015 public int lesskey_src(constant char *filename, lbool sysvar)
1016 {
1017           return lesskey_text(filename, sysvar, FALSE);
1018 }
1019 
lesskey_content(constant char * content,lbool sysvar)1020 public int lesskey_content(constant char *content, lbool sysvar)
1021 {
1022           return lesskey_text(content, sysvar, TRUE);
1023 }
1024 
lesskey_parse_error(char * s)1025 void lesskey_parse_error(char *s)
1026 {
1027           PARG parg;
1028           parg.p_string = s;
1029           error("%s", &parg);
1030 }
1031 #endif /* HAVE_LESSKEYSRC */
1032 
1033 /*
1034  * Add a lesskey file.
1035  */
add_hometable(int (* call_lesskey)(constant char *,lbool),constant char * envname,constant char * def_filename,lbool sysvar)1036 static int add_hometable(int (*call_lesskey)(constant char *, lbool), constant char *envname, constant char *def_filename, lbool sysvar)
1037 {
1038           char *filename = NULL;
1039           constant char *efilename;
1040           int r;
1041 
1042           if (envname != NULL && (efilename = lgetenv(envname)) != NULL)
1043                     filename = save(efilename);
1044           else if (sysvar) /* def_filename is full path */
1045                     filename = save(def_filename);
1046           else /* def_filename is just basename */
1047           {
1048                     /* Remove first char (normally a dot) unless stored in $HOME. */
1049                     constant char *xdg = lgetenv("XDG_CONFIG_HOME");
1050                     if (!isnullenv(xdg))
1051                               filename = dirfile(xdg, &def_filename[1], 1);
1052                     if (filename == NULL)
1053                     {
1054                               constant char *home = lgetenv("HOME");
1055                               if (!isnullenv(home))
1056                               {
1057                                         char *cfg_dir = dirfile(home, ".config", 0);
1058                                         filename = dirfile(cfg_dir, &def_filename[1], 1);
1059                                         free(cfg_dir);
1060                               }
1061                     }
1062                     if (filename == NULL)
1063                               filename = homefile(def_filename);
1064           }
1065           if (filename == NULL)
1066                     return -1;
1067           r = (*call_lesskey)(filename, sysvar);
1068           free(filename);
1069           return (r);
1070 }
1071 
1072 /*
1073  * Add the content of a lesskey source file.
1074  */
add_content_table(int (* call_lesskey)(constant char *,lbool),constant char * envname,lbool sysvar)1075 static void add_content_table(int (*call_lesskey)(constant char *, lbool), constant char *envname, lbool sysvar)
1076 {
1077           (void) call_lesskey; /* not used */
1078           constant char *content = lgetenv(envname);
1079           if (isnullenv(content))
1080                     return;
1081           lesskey_content(content, sysvar);
1082 }
1083 #endif /* USERFILE */
1084 
1085 /*
1086  * See if a char is a special line-editing command.
1087  */
editchar(char c,int flags)1088 public int editchar(char c, int flags)
1089 {
1090           int action;
1091           int nch;
1092           constant char *s;
1093           char usercmd[MAX_CMDLEN+1];
1094 
1095           /*
1096            * An editing character could actually be a sequence of characters;
1097            * for example, an escape sequence sent by pressing the uparrow key.
1098            * To match the editing string, we use the command decoder
1099            * but give it the edit-commands command table
1100            * This table is constructed to match the user's keyboard.
1101            */
1102           if (c == erase_char || c == erase2_char)
1103                     return (EC_BACKSPACE);
1104           if (c == kill_char)
1105           {
1106 #if MSDOS_COMPILER==WIN32C
1107                     if (!win32_kbhit())
1108 #endif
1109                     return (EC_LINEKILL);
1110           }
1111 
1112           /*
1113            * Collect characters in a buffer.
1114            * Start with the one we have, and get more if we need them.
1115            */
1116           nch = 0;
1117           do {
1118                     if (nch > 0)
1119                               c = getcc();
1120                     usercmd[nch] = c;
1121                     usercmd[nch+1] = '\0';
1122                     nch++;
1123                     action = ecmd_decode(usercmd, &s);
1124           } while (action == A_PREFIX && nch < MAX_CMDLEN);
1125 
1126           if (action == EC_X11MOUSE)
1127                     return (x11mouse_action(1));
1128           if (action == EC_X116MOUSE)
1129                     return (x116mouse_action(1));
1130 
1131           if (flags & ECF_NORIGHTLEFT)
1132           {
1133                     switch (action)
1134                     {
1135                     case EC_RIGHT:
1136                     case EC_LEFT:
1137                               action = A_INVALID;
1138                               break;
1139                     }
1140           }
1141 #if CMD_HISTORY
1142           if (flags & ECF_NOHISTORY)
1143           {
1144                     /*
1145                      * The caller says there is no history list.
1146                      * Reject any history-manipulation action.
1147                      */
1148                     switch (action)
1149                     {
1150                     case EC_UP:
1151                     case EC_DOWN:
1152                               action = A_INVALID;
1153                               break;
1154                     }
1155           }
1156 #endif
1157 #if TAB_COMPLETE_FILENAME
1158           if (flags & ECF_NOCOMPLETE)
1159           {
1160                     /*
1161                      * The caller says we don't want any filename completion cmds.
1162                      * Reject them.
1163                      */
1164                     switch (action)
1165                     {
1166                     case EC_F_COMPLETE:
1167                     case EC_B_COMPLETE:
1168                     case EC_EXPAND:
1169                               action = A_INVALID;
1170                               break;
1171                     }
1172           }
1173 #endif
1174           if ((flags & ECF_PEEK) || action == A_INVALID)
1175           {
1176                     /*
1177                      * We're just peeking, or we didn't understand the command.
1178                      * Unget all the characters we read in the loop above.
1179                      * This does NOT include the original character that was
1180                      * passed in as a parameter.
1181                      */
1182                     while (nch > 1)
1183                     {
1184                               ungetcc(usercmd[--nch]);
1185                     }
1186           } else
1187           {
1188                     if (s != NULL)
1189                               ungetsc(s);
1190           }
1191           return action;
1192 }
1193 
1194