src/xrdb.c

   1 /* Deal with the X Resource Manager.
   2    Copyright (C) 1990, 1993-1994, 2000-2017 Free Software Foundation,
   3    Inc.
   4
   5 Author: Joseph Arceneaux
   6 Created: 4/90
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software: you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation, either version 3 of the License, or (at
  13 your option) any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.  */
  22
  23 #include <config.h>
  24
  25 #include <unistd.h>
  26 #include <errno.h>
  27 #include <epaths.h>
  28 #include <stdlib.h>
  29 #include <stdio.h>
  30
  31 #include "lisp.h"
  32
  33 /* This may include sys/types.h, and that somehow loses
  34    if this is not done before the other system files.  */
  35 #include "xterm.h"
  36
  37 #include <X11/Xlib.h>
  38 #include <X11/Xatom.h>
  39 #include <X11/X.h>
  40 #include <X11/Xutil.h>
  41 #include <X11/Xresource.h>
  42 #ifdef HAVE_PWD_H
  43 #include <pwd.h>
  44 #endif
  45
  46 /* X file search path processing.  */
  47
  48
  49 /* The string which gets substituted for the %C escape in XFILESEARCHPATH
  50    and friends, or zero if none was specified.  */
  51 static char *x_customization_string;
  52
  53
  54 /* Return the value of the emacs.customization (Emacs.Customization)
  55    resource, for later use in search path decoding.  If we find no
  56    such resource, return zero.  */
  57 static char *
  58 x_get_customization_string (XrmDatabase db, const char *name,
  59                             const char *class)
  60 {
  61   char *full_name = alloca (strlen (name) + sizeof "customization" + 3);
  62   char *full_class = alloca (strlen (class) + sizeof "Customization" + 3);
  63   char *result;
  64
  65   sprintf (full_name,  "%s.%s", name,  "customization");
  66   sprintf (full_class, "%s.%s", class, "Customization");
  67
  68   result = x_get_string_resource (db, full_name, full_class);
  69   return result ? xstrdup (result) : NULL;
  70 }
  71
  72 /* Expand all the Xt-style %-escapes in STRING, whose length is given
  73    by STRING_LEN.  Here are the escapes we're supposed to recognize:
  74
  75         %N      The value of the application's class name
  76         %T      The value of the type parameter ("app-defaults" in this
  77                 context)
  78         %S      The value of the suffix parameter ("" in this context)
  79         %L      The language string associated with the specified display
  80                 (We use the "LANG" environment variable here, if it's set.)
  81         %l      The language part of the display's language string
  82                 (We treat this just like %L.  If someone can tell us what
  83                  we're really supposed to do, dandy.)
  84         %t      The territory part of the display's language string
  85                 (This never gets used.)
  86         %c      The codeset part of the display's language string
  87                 (This never gets used either.)
  88         %C      The customization string retrieved from the resource
  89                 database associated with display.
  90                 (This is x_customization_string.)
  91
  92    Return the resource database if its file was read successfully, and
  93    refers to %L only when the LANG environment variable is set, or
  94    otherwise provided by X.
  95
  96    ESCAPED_SUFFIX is postpended to STRING if it is non-zero.
  97    %-escapes in ESCAPED_SUFFIX are expanded.
  98
  99    Return NULL otherwise.  */
 100
 101 static XrmDatabase
 102 magic_db (const char *string, ptrdiff_t string_len, const char *class,
 103           const char *escaped_suffix)
 104 {
 105   XrmDatabase db;
 106   char *lang = getenv ("LANG");
 107
 108   ptrdiff_t path_size = 100;
 109   char *path = xmalloc (path_size);
 110   ptrdiff_t path_len = 0;
 111
 112   const char *p = string;
 113
 114   while (p < string + string_len)
 115     {
 116       /* The chunk we're about to stick on the end of result.  */
 117       const char *next = p;
 118       ptrdiff_t next_len = 1;
 119
 120       if (*p == '%')
 121         {
 122           p++;
 123
 124           if (p >= string + string_len)
 125             next_len = 0;
 126           else
 127             switch (*p)
 128               {
 129               case '%':
 130                 next = "%";
 131                 next_len = 1;
 132                 break;
 133
 134               case 'C':
 135                 if (x_customization_string)
 136                   {
 137                     next = x_customization_string;
 138                     next_len = strlen (next);
 139                   }
 140                 else
 141                   next_len = 0;
 142                 break;
 143
 144               case 'N':
 145                 next = class;
 146                 next_len = strlen (class);
 147                 break;
 148
 149               case 'T':
 150                 next = "app-defaults";
 151                 next_len = strlen (next);
 152                 break;
 153
 154               default:
 155               case 'S':
 156                 next_len = 0;
 157                 break;
 158
 159               case 'L':
 160               case 'l':
 161                 if (! lang)
 162                   {
 163                     xfree (path);
 164                     return NULL;
 165                   }
 166
 167                 next = lang;
 168                 next_len = strlen (next);
 169                 break;
 170
 171               case 't':
 172               case 'c':
 173                 xfree (path);
 174                 return NULL;
 175               }
 176         }
 177
 178       /* Do we have room for this component followed by a '\0'?  */
 179       if (path_size - path_len <= next_len)
 180         path = xpalloc (path, &path_size, path_len - path_size + next_len + 1,
 181                         -1, sizeof *path);
 182
 183       memcpy (path + path_len, next, next_len);
 184       path_len += next_len;
 185
 186       p++;
 187
 188       /* If we've reached the end of the string, append ESCAPED_SUFFIX.  */
 189       if (p >= string + string_len && escaped_suffix)
 190         {
 191           string = escaped_suffix;
 192           string_len = strlen (string);
 193           p = string;
 194           escaped_suffix = NULL;
 195         }
 196     }
 197
 198   path[path_len] = '\0';
 199   db = XrmGetFileDatabase (path);
 200   xfree (path);
 201   return db;
 202 }
 203
 204
 205 static char *
 206 gethomedir (void)
 207 {
 208   struct passwd *pw;
 209   char *ptr;
 210   char *copy;
 211
 212   if ((ptr = getenv ("HOME")) == NULL)
 213     {
 214       if ((ptr = getenv ("LOGNAME")) != NULL
 215           || (ptr = getenv ("USER")) != NULL)
 216         pw = getpwnam (ptr);
 217       else
 218         pw = getpwuid (getuid ());
 219
 220       if (pw)
 221         ptr = pw->pw_dir;
 222     }
 223
 224   if (ptr == NULL)
 225     return xstrdup ("/");
 226
 227   ptrdiff_t len = strlen (ptr);
 228   copy = xmalloc (len + 2);
 229   strcpy (copy + len, "/");
 230   return memcpy (copy, ptr, len);
 231 }
 232
 233
 234 /* Find the first element of SEARCH_PATH which exists and is readable,
 235    after expanding the %-escapes.  Return 0 if we didn't find any, and
 236    the path name of the one we found otherwise.  */
 237
 238 static XrmDatabase
 239 search_magic_path (const char *search_path, const char *class,
 240                    const char *escaped_suffix)
 241 {
 242   const char *s, *p;
 243
 244   for (s = search_path; *s; s = p)
 245     {
 246       for (p = s; *p && *p != ':'; p++)
 247         ;
 248
 249       if (p > s)
 250         {
 251           XrmDatabase db = magic_db (s, p - s, class, escaped_suffix);
 252           if (db)
 253             return db;
 254         }
 255       else if (*p == ':')
 256         {
 257           static char const ns[] = "%N%S";
 258           XrmDatabase db = magic_db (ns, strlen (ns), class, escaped_suffix);
 259           if (db)
 260             return db;
 261         }
 262
 263       if (*p == ':')
 264         p++;
 265     }
 266
 267   return 0;
 268 }
 269 \f
 270 /* Producing databases for individual sources.  */
 271
 272 static XrmDatabase
 273 get_system_app (const char *class)
 274 {
 275   const char *path;
 276
 277   path = getenv ("XFILESEARCHPATH");
 278   if (! path) path = PATH_X_DEFAULTS;
 279
 280   return search_magic_path (path, class, 0);
 281 }
 282
 283
 284 static XrmDatabase
 285 get_fallback (Display *display)
 286 {
 287   return NULL;
 288 }
 289
 290
 291 static XrmDatabase
 292 get_user_app (const char *class)
 293 {
 294   XrmDatabase db = 0;
 295   const char *path;
 296
 297   /* Check for XUSERFILESEARCHPATH.  It is a path of complete file
 298      names, not directories.  */
 299   path = getenv ("XUSERFILESEARCHPATH");
 300   if (path)
 301     db = search_magic_path (path, class, 0);
 302
 303   if (! db)
 304     {
 305       /* Check for APPLRESDIR; it is a path of directories.  In each,
 306          we have to search for LANG/CLASS and then CLASS.  */
 307       path = getenv ("XAPPLRESDIR");
 308       if (path)
 309         {
 310           db = search_magic_path (path, class, "/%L/%N");
 311           if (!db)
 312             db = search_magic_path (path, class, "/%N");
 313         }
 314     }
 315
 316   if (! db)
 317     {
 318       /* Check in the home directory.  This is a bit of a hack; let's
 319          hope one's home directory doesn't contain any %-escapes.  */
 320       char *home = gethomedir ();
 321       db = search_magic_path (home, class, "%L/%N");
 322       if (! db)
 323         db = search_magic_path (home, class, "%N");
 324       xfree (home);
 325     }
 326
 327   return db;
 328 }
 329
 330 static char const xdefaults[] = ".Xdefaults";
 331
 332 static XrmDatabase
 333 get_user_db (Display *display)
 334 {
 335   XrmDatabase db;
 336   char *xdefs;
 337
 338 #ifdef PBaseSize                /* Cheap way to test for X11R4 or later.  */
 339   xdefs = XResourceManagerString (display);
 340 #else
 341   xdefs = display->xdefaults;
 342 #endif
 343
 344   if (xdefs != NULL)
 345     db = XrmGetStringDatabase (xdefs);
 346   else
 347     {
 348       /* Use ~/.Xdefaults.  */
 349       char *home = gethomedir ();
 350       ptrdiff_t homelen = strlen (home);
 351       char *filename = xrealloc (home, homelen + sizeof xdefaults);
 352       strcpy (filename + homelen, xdefaults);
 353       db = XrmGetFileDatabase (filename);
 354       xfree (filename);
 355     }
 356
 357 #ifdef HAVE_XSCREENRESOURCESTRING
 358   /* Get the screen-specific resources too.  */
 359   xdefs = XScreenResourceString (DefaultScreenOfDisplay (display));
 360   if (xdefs != NULL)
 361     {
 362       XrmMergeDatabases (XrmGetStringDatabase (xdefs), &db);
 363       XFree (xdefs);
 364     }
 365 #endif
 366
 367   return db;
 368 }
 369
 370 static XrmDatabase
 371 get_environ_db (void)
 372 {
 373   XrmDatabase db;
 374   char *p = getenv ("XENVIRONMENT");
 375   char *filename = 0;
 376
 377   if (!p)
 378     {
 379       /* Use ~/.Xdefaults-HOSTNAME.  */
 380       char *home = gethomedir ();
 381       ptrdiff_t homelen = strlen (home);
 382       Lisp_Object system_name = Fsystem_name ();
 383       ptrdiff_t filenamesize = (homelen + sizeof xdefaults
 384                                 + 1 + SBYTES (system_name));
 385       p = filename = xrealloc (home, filenamesize);
 386       lispstpcpy (stpcpy (stpcpy (filename + homelen, xdefaults), "-"),
 387                   system_name);
 388     }
 389
 390   db = XrmGetFileDatabase (p);
 391
 392   xfree (filename);
 393
 394   return db;
 395 }
 396 \f
 397 /* External interface.  */
 398
 399 /* Types of values that we can find in a database */
 400
 401 #define XrmStringType "String"  /* String representation */
 402 static XrmRepresentation x_rm_string;   /* Quark representation */
 403
 404 /* Load X resources based on the display and a possible -xrm option. */
 405
 406 XrmDatabase
 407 x_load_resources (Display *display, const char *xrm_string,
 408                   const char *myname, const char *myclass)
 409 {
 410   XrmDatabase user_database;
 411   XrmDatabase rdb;
 412   XrmDatabase db;
 413   char line[256];
 414
 415 #if defined USE_MOTIF || !defined HAVE_XFT || !defined USE_LUCID
 416   const char *helv = "-*-helvetica-medium-r-*--*-120-*-*-*-*-iso8859-1";
 417 #endif
 418
 419 #ifdef USE_MOTIF
 420   const char *courier = "-*-courier-medium-r-*-*-*-120-*-*-*-*-iso8859-1";
 421 #endif
 422
 423   x_rm_string = XrmStringToQuark (XrmStringType);
 424 #ifndef USE_X_TOOLKIT
 425   /* pmr@osf.org says this shouldn't be done if USE_X_TOOLKIT.
 426      I suspect it's because the toolkit version does this elsewhere.  */
 427   XrmInitialize ();
 428 #endif
 429   rdb = XrmGetStringDatabase ("");
 430
 431   /* Add some font defaults.  If the font `helv' doesn't exist, widgets
 432      will use some other default font.  */
 433 #ifdef USE_MOTIF
 434
 435   sprintf (line, "%s.pane.background: grey75", myclass);
 436   XrmPutLineResource (&rdb, line);
 437   sprintf (line, "%s*fontList: %s", myclass, helv);
 438   XrmPutLineResource (&rdb, line);
 439   sprintf (line, "%s*menu*background: grey75", myclass);
 440   XrmPutLineResource (&rdb, line);
 441   sprintf (line, "%s*menubar*background: grey75", myclass);
 442   XrmPutLineResource (&rdb, line);
 443   sprintf (line, "%s*verticalScrollBar.background: grey75", myclass);
 444   XrmPutLineResource (&rdb, line);
 445   sprintf (line, "%s*verticalScrollBar.troughColor: grey75", myclass);
 446   XrmPutLineResource (&rdb, line);
 447   sprintf (line, "%s*horizontalScrollBar.background: grey75", myclass);
 448   XrmPutLineResource (&rdb, line);
 449   sprintf (line, "%s*horizontalScrollBar.troughColor: grey75", myclass);
 450   XrmPutLineResource (&rdb, line);
 451   sprintf (line, "%s.dialog*.background: grey75", myclass);
 452   XrmPutLineResource (&rdb, line);
 453   sprintf (line, "%s*fsb.Text.background: white", myclass);
 454   XrmPutLineResource (&rdb, line);
 455   sprintf (line, "%s*fsb.FilterText.background: white", myclass);
 456   XrmPutLineResource (&rdb, line);
 457   sprintf (line, "%s*fsb*DirList.background: white", myclass);
 458   XrmPutLineResource (&rdb, line);
 459   sprintf (line, "%s*fsb*ItemsList.background: white", myclass);
 460   XrmPutLineResource (&rdb, line);
 461   sprintf (line, "%s*fsb*background: grey75", myclass);
 462   XrmPutLineResource (&rdb, line);
 463   sprintf (line, "%s*fsb.Text.fontList: %s", myclass, courier);
 464   XrmPutLineResource (&rdb, line);
 465   sprintf (line, "%s*fsb.FilterText.fontList: %s", myclass, courier);
 466   XrmPutLineResource (&rdb, line);
 467   sprintf (line, "%s*fsb*ItemsList.fontList: %s", myclass, courier);
 468   XrmPutLineResource (&rdb, line);
 469   sprintf (line, "%s*fsb*DirList.fontList: %s", myclass, courier);
 470   XrmPutLineResource (&rdb, line);
 471
 472   /* Set double click time of list boxes in the file selection
 473      dialog from `double-click-time'.  */
 474   if (INTEGERP (Vdouble_click_time) && XINT (Vdouble_click_time) > 0)
 475     {
 476       sprintf (line, "%s*fsb*DirList.doubleClickInterval: %"pI"d",
 477                myclass, XFASTINT (Vdouble_click_time));
 478       XrmPutLineResource (&rdb, line);
 479       sprintf (line, "%s*fsb*ItemsList.doubleClickInterval: %"pI"d",
 480                myclass, XFASTINT (Vdouble_click_time));
 481       XrmPutLineResource (&rdb, line);
 482     }
 483
 484 #else /* not USE_MOTIF */
 485
 486   sprintf (line, "Emacs.dialog*.background: grey75");
 487   XrmPutLineResource (&rdb, line);
 488 #if !defined (HAVE_XFT) || !defined (USE_LUCID)
 489   sprintf (line, "Emacs.dialog*.font: %s", helv);
 490   XrmPutLineResource (&rdb, line);
 491   sprintf (line, "*XlwMenu*font: %s", helv);
 492   XrmPutLineResource (&rdb, line);
 493 #endif
 494   sprintf (line, "*XlwMenu*background: grey75");
 495   XrmPutLineResource (&rdb, line);
 496   sprintf (line, "Emacs*verticalScrollBar.background: grey75");
 497   XrmPutLineResource (&rdb, line);
 498   sprintf (line, "Emacs*horizontalScrollBar.background: grey75");
 499   XrmPutLineResource (&rdb, line);
 500
 501 #endif /* not USE_MOTIF */
 502
 503   user_database = get_user_db (display);
 504
 505   /* Figure out what the "customization string" is, so we can use it
 506      to decode paths.  */
 507   xfree (x_customization_string);
 508   x_customization_string
 509     = x_get_customization_string (user_database, myname, myclass);
 510
 511   /* Get application system defaults */
 512   db = get_system_app (myclass);
 513   if (db != NULL)
 514     XrmMergeDatabases (db, &rdb);
 515
 516   /* Get Fallback resources */
 517   db = get_fallback (display);
 518   if (db != NULL)
 519     XrmMergeDatabases (db, &rdb);
 520
 521   /* Get application user defaults */
 522   db = get_user_app (myclass);
 523   if (db != NULL)
 524     XrmMergeDatabases (db, &rdb);
 525
 526   /* get User defaults */
 527   if (user_database != NULL)
 528     XrmMergeDatabases (user_database, &rdb);
 529
 530   /* Get Environment defaults. */
 531   db = get_environ_db ();
 532   if (db != NULL)
 533     XrmMergeDatabases (db, &rdb);
 534
 535   /* Last, merge in any specification from the command line. */
 536   if (xrm_string != NULL)
 537     {
 538       db = XrmGetStringDatabase (xrm_string);
 539       if (db != NULL)
 540         XrmMergeDatabases (db, &rdb);
 541     }
 542
 543   return rdb;
 544 }
 545
 546
 547 /* Retrieve the value of the resource specified by NAME with class CLASS
 548    and of type TYPE from database RDB.  The value is returned in RET_VALUE. */
 549
 550 static int
 551 x_get_resource (XrmDatabase rdb, const char *name, const char *class,
 552                 XrmRepresentation expected_type, XrmValue *ret_value)
 553 {
 554   XrmValue value;
 555   XrmName namelist[100];
 556   XrmClass classlist[100];
 557   XrmRepresentation type;
 558
 559   XrmStringToNameList (name, namelist);
 560   XrmStringToClassList (class, classlist);
 561
 562   if (XrmQGetResource (rdb, namelist, classlist, &type, &value) == True
 563       && (type == expected_type))
 564     {
 565       if (type == x_rm_string)
 566         ret_value->addr = (char *) value.addr;
 567       else
 568         memcpy (ret_value->addr, value.addr, ret_value->size);
 569
 570       return value.size;
 571     }
 572
 573   return 0;
 574 }
 575
 576 /* Retrieve the string resource specified by NAME with CLASS from
 577    database RDB. */
 578
 579 char *
 580 x_get_string_resource (XrmDatabase rdb, const char *name, const char *class)
 581 {
 582   XrmValue value;
 583
 584   if (inhibit_x_resources)
 585     /* --quick was passed, so this is a no-op.  */
 586     return NULL;
 587
 588   if (x_get_resource (rdb, name, class, x_rm_string, &value))
 589     return (char *) value.addr;
 590
 591   return 0;
 592 }
 593 \f
 594 /* Stand-alone test facilities.  */
 595
 596 #ifdef TESTRM
 597
 598 typedef char **List;
 599 #define arg_listify(len, list) (list)
 600 #define car(list) (*(list))
 601 #define cdr(list) (list + 1)
 602 #define NIL(list) (! *(list))
 603 #define free_arglist(list)
 604
 605 static List
 606 member (char *elt, List list)
 607 {
 608   List p;
 609
 610   for (p = list; ! NIL (p); p = cdr (p))
 611     if (! strcmp (elt, car (p)))
 612       return p;
 613
 614   return p;
 615 }
 616
 617 static void
 618 fatal (char *msg, char *prog)
 619 {
 620   fprintf (stderr, msg, prog);
 621   exit (1);
 622 }
 623
 624 int
 625 main (int argc, char **argv)
 626 {
 627   Display *display;
 628   char *displayname, *resource_string, *class, *name;
 629   XrmDatabase xdb;
 630   List arg_list, lp;
 631
 632   arg_list = arg_listify (argc, argv);
 633
 634   lp = member ("-d", arg_list);
 635   if (!NIL (lp))
 636     displayname = car (cdr (lp));
 637   else
 638     displayname = "localhost:0.0";
 639
 640   lp = member ("-xrm", arg_list);
 641   resource_string = NIL (lp) ? 0 : car (cdr (lp));
 642
 643   lp = member ("-c", arg_list);
 644   if (! NIL (lp))
 645     class = car (cdr (lp));
 646   else
 647     class = "Emacs";
 648
 649   lp = member ("-n", arg_list);
 650   if (! NIL (lp))
 651     name = car (cdr (lp));
 652   else
 653     name = "emacs";
 654
 655   free_arglist (arg_list);
 656
 657   if (!(display = XOpenDisplay (displayname)))
 658     fatal ("Can't open display '%s'\n", XDisplayName (displayname));
 659
 660   xdb = x_load_resources (display, resource_string, name, class);
 661
 662   /* In a real program, you'd want to also do this: */
 663   display->db = xdb;
 664
 665   while (true)
 666     {
 667       char query_name[90];
 668       char query_class[90];
 669
 670       printf ("Name: ");
 671       gets (query_name);
 672
 673       if (strlen (query_name))
 674         {
 675           char *value;
 676
 677           printf ("Class: ");
 678           gets (query_class);
 679
 680           value = x_get_string_resource (xdb, query_name, query_class);
 681
 682           if (value != NULL)
 683             printf ("\t%s(%s):  %s\n\n", query_name, query_class, value);
 684           else
 685             printf ("\tNo Value.\n\n");
 686         }
 687       else
 688         break;
 689     }
 690   printf ("\tExit.\n\n");
 691
 692   XCloseDisplay (display);
 693
 694   return 0;
 695 }
 696 #endif /* TESTRM */